Hoophouse Baseboards: wood, steel or recycled plastic?

 

Our first year shadecloth with ropes to hooks in our cedar baseboards.

This post is not for everyone, but it shows where my head has been this week. Even if you don’t have a hoophouse, or are not even thinking about getting one,you might be interested in recycled plastic decking boards, or buying repurposed material from an “industrial thrift store”!

We made cedar baseboards when we put up our hoophouse 20+ years ago, and they have rotted. We have done partial replacements, including a major one maybe five years ago, but are now considering either plastic decking “lumber” (recycled plastic, with or without any wood filler), or steel.

I did some research:

https://hightunnels.org/design-construction-of-high-tunnels-west-virginia/ Lewis Jett (WV Extension)

“Baseboards and hip boards add strength to the base of the frame (Figure 8). For most high tunnel frames, 2 inches x 6 inches x 10 feet wood (or recycled plastic) boards are suitable. Pressure-treated wood can be used for both hipboards and baseboards. Each section of baseboard is bolted onto the ground post or secured with a pipe strap. The baseboard and hipboard must be level across the length of the high tunnel. Each joint between sections can be spliced with a small segment of board.” Our hoophouse is 96ft long, so we’d need 192ft plus some way of joining them (metal brackets?)

So, same dimensions, whether wood or plastic. 2” x 6” x 10’. We don’t need “structural grade” lumber (wood or plastic) as the ground-posts provide the strength and are not going to move sideways.

Next, I asked local growers: Do any of you have advice based on experience?

Replies ranged across the spectrum

  1. Sounds like cedar serves well for that. 20 years is a good run for wood. Maybe locust or old chestnut barn boards would serve well, too.
  2. We replaced the rotting wood baseboard with plastic deck “wood” about 5 years ago and haven’t had any problems with it.  Didn’t even think about using steel.   Ignorance is bliss.
  3. When we redo base boards I would like to go with hat channel.  I think sidewalls would air seal better and I’m finding that more important than insulation value. We’ve been putting straw on the tunnel edges for weed control and insulation for the winter.

I replied: We’re not content with living with the state of decline of the wood. Currently we have about 12 ft of the south wall where the plastic and wigglewire channel are not attached to the earth. We have to fix that before the chills of winter get in!

Wood

See the ATTRA publication Pressure-Treated Wood: Organic and natural Alternatives 2011. Be aware that many of the alternative lumber treatments described in the ATTRA article are NOT currently allowed for use on organic farms.  Certified farms should consult their Organic certifier.

“Lumber treated with prohibited materials is not allowed under the National Organic Program (NOP) Regulations. The NOP prohibits most but not all synthetics. Lumber is pressure treated to resist insects and fungi, but the materials used are toxic to humans. For posts and lumber that are in contact with soil, crops, or livestock, the options include untreated lumber, alternatively treated lumber, alternative plywood products, and untreated fence posts.

Borates (boric acids and borax) have long been used for alternative wood protection and can be used with all types of lumber, logs, and ply-wood. Borax, a naturally occurring mined material, is allowed for organic production. Borates and boric acid are synthetic substances allowed for use as an insecticide in organic production as what is described in the National List 205.601 as a “structural pest control, [not in] direct contact with organic food or crops.” Borate-treated lumber and borate wood treatments are available commercially.

Borate wood treatments will penetrate to the center of the wood when the wood is dipped, especially when the wood is freshly cut or when seasoned wood is rewetted. Because borates are water soluble; however, they will leach from the wood when in contact with water in the soil, leaving the wood unprotected. This is the reason that borate-treated lumber should be used only in locations that are at least six inches above the ground and protected from excessive rain. Borate-treated wood is not considered suitable for unprotected outdoor use, such as for fence posts or poles, but it is suitable for most building-construction purposes.”

Recycled Plastic Lumber and Plastic/Wood Composite Lumber

(from ATTRA 2011)

“Lumber” made of recycled plastic or composites of plastic and wood can provide durable weather-resistant alternatives to wood for some applications. In organic operations, formed plastic is approved only for use in nonstructural applications because it doesn’t have strength comparable to wood. However, plastic lumber can easily substitute for treated wood in nonstructural applications such as fences, sill plates, and raised beds. The plastics are rot- and corrosion-proof and don’t crack, splinter, or chip. Even in exposed and sub-grade conditions, plastic lumber has a long life expectancy. It will not leach chemicals into the ground, surface water or soil as treated wood can. A challenging aspect of working with plastic lumber is its relatively high likelihood of expanding, which varies for each product and manufacturer and has to be considered during installation. Thermal expansion is the change in dimensions of a material due to temperature changes.

The number of plastic-lumber manufacturers and their variety of products has notably increased recently. Some companies use only High Density Polyethylene (HDPE) plastic, while others use commingled plastic wastes. A few manufacturers even mix plastic with recycled tire rubber. Some plastic lumber will contain wood fiber, which helps strengthen the plastic and reduces expansion.

Plastic lumber is available in many configurations and sizes, including solid- and hollow-core dimensional products and tongue-and-groove designs. The quality and product performance will vary by manufacturer; many manufacturers have independent testing results available.”

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The Composite Lumber Manufacturers Association offers publications and links to member companies that manufacture and distribute plastic lumber. See All About Composite Decking. It requires no maintenance, comes in lengths up to 20ft, can be fastened with self-drilling screws, and can be drilled and sawn with power or hand tools used for wood.

The California Integrated Waste Management Board Recycled Plastic Lumber website provides a good introduction to the types and uses of recycled-plastic-lumber products.

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Suppliers of plastic lumber

Growers Supply has 2” x 6” x 8’or 12’ recycled plastic boards in black (Expands in heat, don’t buy dark color?). We’d need 16 boards at 12ft long ($1887.20 plus shipping), or 24 at 8ft long ($1894.80 plus shipping). Can get 10% discount. “A 12foot board will shrink .029/inches over a 5 degree drop in temperature. Note your starting point is what temperature the board started at when assembled. Typically use 60 degrees as a baseline. In this case a temperature drop to 0 degrees will net 11/32″ over the 60degree swing. A direct sunlight board will shrink less in a temperature drop and expand more in a temperature increase.”

On decks, the boards are tightly fastened every 16” and can’t go anywhere much sideways.

Home Depot and Lowes only have short pieces.

Plastic Lumber Yard, PA. Can get 5% discount.

Premium Grade is the nicest looking, and best for decking. Structural grade is reinforced with fiberglass, making it stiffer, the best under high traffic. Molded grade is recycled high-density polyethylene (HDPE), suitable for landscaping, buildings and near food.

Molded grade 2” x 6” x 12’ $126.23 each. $2,019.68 for us (plus shipping) Available in 8, 10, 12, 14, 16ft lengths and many colors. This grade would work for baseboards.

Their Clearance dept might be useful, as we probably don’t care exactly what color it is, or even if it’s all the same color. Currently they have 2” x 6” x 12’ in white for $76.50 each ($1224 for 192 ft) and a grey board with peg joins 1 7/8’ x 5 7/8” x 12’ for $50 each, but they only have 9 left! 2” x 6” x 8‘ black (severe “dog-bone”, meaning the boards are thinner in the middle than along the edges. (Oops! We all have days like that) for $30.16 each – must buy all 36 pieces. We only need 24. info@plasticlumberyard.com or call (610) 277-3900 for shipping info.

Markstaar 888-846-2693 Offering double discounts right now. Recycled lumber boards.

2” x 6” x 12’ $48.96; 2” x 6” x 8’ $32.64. (24 for $783.36) Black is cheapest.

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Metal baseboards

Steel is available as either “hat” profile strips from greenhouse suppliers, or metal joists, 6″ wide, C-cross-section. They look easiest to use, but have zero insulating value.

I’ve found some steel joists on https://www.repurposedmaterialsinc.com/ . This is a fun website, saving all sorts of good stuff from going to the landfill.

  1. Hat channel Join by overlapping sections and using self-tapping screws. Tunnel Vision has an installation video on Hat Channel. $54.74 for a 12’3” length 5” wide. 18-gauge steel. ($875.84 plus shipping for 16 lengths) Truck delivery for full-length strips, or they will cut them in half for ground delivery.

Boot Strap Farmer also has a video with hat channel. 6.5’ lengths, $452.99 for a 10-pack. (65’). We’d need three 10-packs, $1358.97 plus shipping. And lots of joins. . .

  1. Square tubing
  2. Steel C-section joists

RepurposedMaterials is a fun website, saving all sorts of good stuff from going to the landfill. I need to compare prices, shipping and practicality. Steel is looking better right now.  has different things at different times, naturally enough.

Structural Steel Stud

$78 for almost 20ft length. 12″ x 2″ 14 gauge C-shape plus curved over edges. We’d need 10 lengths and would spend $780 Plus Shipping

Track square cornered c-shape

$48 for 20ft.  10″ x 1.25″ 18 gauge We’d spend $480 plus shipping from SC

Structural Steel Track

$45. 20′ x 11-1/4″ x 1-1/2″. 18 gauge. Square cornered, no curved in edges. We’d spend $450 plus shipping.

Wood Recycled Plastic Hat Channel Repurposed joist
Price $783.36/

$1224/

$1887.20/ $2,019.68

$875.84/

$1358.97

$450 /

$480 /

$780/

 

Pluses Recycled,

No maintenance

No maintenance Saving waste

Price is good

Minuses Rots Expands.

Leaches? They say not

Shipping might be high (heavy)

 

 

 

Book Review Farming on the Wild Side, The Evolution of a Regenerative Organic Farm and Nursery, Nancy and John Hayden

Farming On The Wild Side book cover. Chelsea Green.
Book Review Farming on the Wild Side, The Evolution of a Regenerative Organic Farm and Nursery, Nancy and John Hayden, Chelsea Green, 2019. 258 pages, $29.95.

This is a lovely, thoughtful, well-illustrated book, telling how Nancy and John Hayden changed their farm (formerly a conventional dairy farm) over three decades into a regenerative farm, now specializing in perennial fruit trees. Their focus has been on stewarding the land mindfully, restoring and increasing biodiversity. In these uncertain times, there is much we can’t do alone, and we worry if enough people will make enough of the necessary changes. We can, instead, focus on positive changes we can make to improve our world. Growing and nurturing plants will benefit you, the plants and the planet.

The Haydens have an 18-acre farm in northern Vermont with undulating land, and a wide range of soil types. Very different from central Virginia, where I live! Both moved to Syracuse, NY to study biology and ecology, and after meeting at university, they worked in the Peace Corps on opposite sides of the African continent. Nancy worked in Kenya, supporting small farmers installing fishponds. John was in Mali, helping market gardeners and farmers, especially in dealing with millet pests. They both grew intellectually, emotionally and spiritually, with broader worldviews, awareness of white privilege, and deeper understanding of solitude and loneliness.

After Peace Corps, they reunited, married and began graduate school at Michigan State U, studying entomology (John) and environmental engineering (Nancy). John hankered to start a farm, so when Nancy was offered a post at the University of Vermont, they packed up the family and moved. A few months later, they bought their farm. It was a well-manicured conventional dairy farm with a cathedral-like barn built in 1900. The lawns are now orchards, and the stream banks host fruit bushes and small trees. The focus these days is on biodiversity and a regenerative food system, not on “pretty”. You can see before and after photos, and sketch maps of their farm (The Farm Between).

The book includes a valuable chart summarizing their practices and events during each of the three decades of their farm life so far. This shows how changes can be made as interests and focus shift. Long-term sustainability for aging farmers!

In the initial years their goals were to feed their family high quality food (hard to find to buy in the 1990’s), treat livestock humanely, regenerate the land for long-term health, and generate income from farming. They grew organic annual vegetables and raised grass-fed poultry, rabbits, sheep and pigs for a meat CSA. They also raised young children, and a family cow. The farm hosted field trips from local elementary schools, and Nancy became an associate professor.

John and Nancy got inspiration from Holistic Resource Management, as well as many small-farming pioneers. HRM led them to learn and practice management intensive grazing. This involves carefully matching stocking density with the health of the pastures, leading to continuous improvement. Paddocks just large enough, and no bigger, encourage livestock to graze all the plants down, leading to lush and nutritious regrowth. Initially their pastures were overrun with reed canary grass, and just one year of intensive grazing management with sheep started to bring improvements.

They also raised chickens and rabbits in moveable pens (chicken tractors), and quickly devised improvements to the pen design and the choice of breed. They trained all their livestock to come running when they heard grain shaken in a bucket. This good habit saved them from problems when livestock got loose onto the busy state road.

In the middle decade (roughly the 2000’s), the children grew up and left home, John became a lecturer on Plant and Soil Science, the field trips included special needs children and summer camps for middle-schoolers. They became more focused on resilience, biodiversity and pollinators. Keeping livestock makes it hard for a farming couple or family to vacation at the same time, and well-trained farm sitters are worth a lot!

Raising animals in confined spaces, feeding mostly corn and soy and antibiotics, while exploiting workers and degrading the environment is a disgrace to our society. Slaughtering animals is tough, and where possible, the Haydens opted for on-farm slaughter, as less stressful and more humane. The Haydens cut back on meat production and expanded perennial and annual food crops.

After 20 years of learning and practicing with draft horses during visits to working horse farms, and after 10 years at The Farm Between, John bought his own team of two Clydesdales. This helped them successfully expand their vegetable and small fruit production. From 2004-2011, they put up five hoophouses, initially for tomatoes and other valuable vegetables. They could pay for the structures and the wages in one year by growing cherry tomatoes in each new hoophouse. This increased their resilience in the face of extreme weather of various kinds, and in 2009, they planted a few rows of fall raspberries in one of the hoophouses. These did so well that the next year they planted one whole hoophouse full.

The third decade (after serious flooding from Hurricane Irene in 2011) brought a forceful introduction to the reality of climate change. Their focus on improving the soil has included a major composting operation. The Haydens have succeeded in doubling the organic matter in their soils from 2.5 to 6% over the years. Initially John collected food scraps to feed their chickens and then compost. But the heavy lifting and the rats got to him.

It takes 500 years or more to grow an inch of soil, which is all too easily lost to wind and water erosion. Growing cover crops holds the soil in place while adding organic matter. While they grew mostly annual vegetables, the Haydens used at least one-third of their land for growing cover crops, usually including legumes, to add nitrogen to the soil. Growing annual vegetables is stressful. Everything is urgent and important, all season! Perennials allow more flexibility, for example in the timing of weeding and pruning.

They committed more to perennial polyculture, retired the horses and bought a tractor. Fruit planting had expanded every year, with perennial vegetables and annual hemp in the alleys between the rows. Other alleys are left unmowed to encourage milkweed (selling seeds and floss). All the while, the edges and hedges have provided biological diversity for insects, birds and other creatures.

Nancy Hayden, author of Farming on the Wild Side

They repurposed all their hoophouses to grow fruit, protected from the elements as well as pests and diseases. They have dwarf apple trees (blemish-free no-spray organic apples!), cherries, peaches, plums, apricots and raspberries. Outdoors they grow hazelberts, elderberries, aronia, honeyberry, gooseberries, blackcurrants, red and white currents, and many blueberries. The increased fruit production led them to work with cider producers and market other fruit products including selling at the Burlington Farmers’ Market. They started a retail nursey of fruit trees on the farm, alongside fruit sales. Operating a fruit tree nursey at the farm enables the farmers to attract customers who are very interested in what they are doing, and will encourage and support them in growing their own fruit. Nancy retired from UVM. They expanded on-farm workshops, field trips and classes for all ages.

They were able to provide free housing for their employees and pay them above minimum wage. Despite the obvious success of their farm stand, farmers’ market, meat and produce CSAs, restaurant and grocery accounts, they were not quite satisfied. The family were eating well, and Nancy’s off-farm income kept them afloat and allowed them to build up the farm infrastructure. John was working 60-80 hours a week on the farm, but not producing much net income for the four-child family they were now raising. John calculated he was earning half minimum wage, and the only way that was being “successful” was that the 80 hour weeks made two half-minimum wages! Their aging bodies had also become a factor to consider. Also, Nancy and John developed interests that vied for their attention, much as they were still committed to the farm.

They had noticed their soil structure was deteriorating, even though the organic matter content was increasing. They studied approaches to deal with soil loss and degradation, climate disruption, water and air pollution, declining food quality and loss of biodiversity. The book includes a valuable chart listing stressors in the categories of environmental, social, economic and personal stresses, and resilience strategies to tackle each.

The Haydens committed to be more proactive in benefiting the land, and becoming more economically resilient. Their approach was a synthesis of:

  • resilience (ability to bounce back from stresses and shocks),
  • organic farming (nurture healthy soil to grow healthy crops and healthy people: it’s about the soil, not about the certificate),
  • regenerative organic (rebuild soil organic matter, increase biodiversity, improve water quality and slow the pace of climate change),
  • agroecology (approaching agriculture by combining ecology, biology, agronomy, plant physiology and more, improving soils and water, biodiversity, species conservation, carbon sequestration),
  • permaculture (“permanent agriculture”, integrative perennial-based systems, working with the natural environment, providing for the needs of people locally),
  • agroforestry (intentionally incorporating trees and shrubs into farming systems for the benefit of the environment, the community and the farm,)
  • biodynamics (considering each farm as a unique integrated organism, raising crops and livestock synergistically)
  • wabi sabi (finding beauty and value in the impermanent, the natural cycles of growth, death and decay.)
  • rewilding (letting banks, ditches, shrubs and trees grow back, providing shelter and food for many more insects and birds; planting orchards in place of lawns,
  • personal spiritual traditions (focusing on nature and natural cycles)

As a result of considering all these approaches, Nancy and John found themselves drawn to wholesaling fruit, particularly to local wineries. They wanted no-spray organic fruit, pointing out that organic fungicides and broad-spectrum insecticides are toxic to pollinators and other beneficial insects, as well as the pest species.

In August 1995, a few years after John and Nancy moved to the farm, the summer drought was broken by three days of rain upstream of the farm. The river overflowed, flooding the low fields and the barn three feet deep. The water level receded the next day, leaving a big mess, including dead chicks and destroyed equipment. The house was on higher ground, and was not affected.

In 2011, they got a 500-year flood in April and a repeat with Hurricane Irene in August.  They lost their potato and corn crops, and noticed that the perennial fruit bushes and conservation shrubs recovered just fine when the water receded. They decided not to grow annual crops in the low-lying Field Six any more, but instead plant elderberries and aronia, which tolerate some flooding.

As they transitioned to growing mostly perennials, they also stopped tilling. They sheet mulch around newly planted fruit trees and berry bushes, with either cardboard and woodchips, or with landscape fabric rolls with “seam-lines” along the planting rows. This means they can open the overlapping pieces in spring or fall to add soil amendments. They’ve also used this technique to grow pumpkins, sunflowers and CBD hemp in the alleys between young fruit trees. They also employ a “grow, mow and blow” in the alleys to deposit home-grown mulch around the trees.

Transitioning to more perennials in polyculture orchards led them to incorporate agroforestry practices such as hedges, biomass trees, and riparian forest zones (next to streams). Hedgerows act as windbreaks, as well as enhancing biodiversity, and reducing soil erosion and offering sanctuary to many kinds of wildlife.

The apple orchards provide scion wood for selling and for grafting to make new trees. Between new fruit trees, in the rows, they plant blackcurrants and other fruit bushes, nitrogen-fixing small trees and perennial wildflowers. These infill plants will be chopped or lopped for mulch when the apple trees need the space.

Perennial vegetables also have a place on the farm. Asparagus and rhubarb have been there for over 20 years. Sea kale and Jerusalem artichokes are more recent additions, in the alleys between apple trees. Remember this book is written in Vermont, where rhubarb ripens in June, blueberries in July and elderberries in late summer. Follow the concepts, not the details, if you are in a very different climate zone.

Climate change in Vermont has, so far, meant warmer, earlier springs, which can cause trees to break bud, risking crop death by frosts in May. Using hoophouses for fruit can reduce risk. Leave the hoophouse open all winter, but if a spring frost threatens during or after bloom, close the house up for the night. “Fruit trees can break your heart,” the authors warn.

John Hayden, Author of Farming on the Wild Side

The section on rootstocks, scion wood and grafting explains how to propagate trees. Growing polycultural orchards reduces dependency on any particular variety or type, and makes organic production much more viable, as pest or disease outbreaks are rarer and other crops compensate for whichever is taken down. There’s a nice list of the ten best apple varieties at the farm, and one of stone fruit cultivars. Again, remember this is Vermont, zone 4a.

The farm also grows many less common cold-hardy berries. Blackcurrants do well in Vermont, but I know from experience that they do poorly in the South. The yield is plentiful, but the harvest slow. Their target rate is ten pounds an hour. The variety Tatania is their highest-yielding, at 4.7 pounds per bush. A useful tip is to stand still and move the branches towards you, rather than moving yourself a lot. There are tips on good varieties of berries too.

Elderberries and Aronia have already been mentioned as flood-tolerant. Both also require full sun. they are high in anti-oxidants, and attract wildlife, unfortunately including Spotted Wing Drosophila, which cause the berries to drop before the whole panicle is ripe. The solution is to pick every few days, removing the ripe parts of the clusters. Note that American elderberries need to be cooked or fermented before eating, as they contain cyanide-inducing compounds.

The farm has an area of boxed propagation beds where they raise hardwood cuttings to grow bushes for sale. They have a space where customers can see full-size plants in a natural setting. This area supports many pollinators, as does their willow labyrinth. There is a mowed walking path around the pollinator sanctuary, where visitors love to observe plants, insects, birds, and other wildlife. The riparian zone is part of a contiguous wildlife corridor connecting the woods and the farm, and providing edges with meadows and cropland. Common milkweed in the orchard alleys is promoted by mowing the grass early, before the milkweed emerges.

The chapter on pests and diseases invites us to rethink these life-forms. Weed management is necessary. Birds can be “pests” on fruit crops during the harvest period. Netting the berries at this time and then removing the nets to let the birds in to clean up the dropped berries helps reduce other pest problems, such as SWD. At the time the book was written, their way of dealing with the SWD was to net individual panicles of elderberries using nylon “footies.” Crop diversity reduces potential crop losses and pest outbreaks.

The Haydens dispute the myth that pests on a plant show the plant is unhealthy or that the soil conditions are wrong. Having a diversity of insects shows a natural balance. If the number of pests increases to the point of causing economic damage, that’s a pest outbreak, and needs action. Having a low level of pest insects keeps predators and parasites provided for! Always look for parasites, such as the white fly eggs on the thorax of the Japanese beetles. Everything may be being taken care of! Wiping everyone out with pesticides causes imbalance, and the pest populations can come back faster than their predators. The true parasites are the pesticide companies, say the authors!

Attention is also paid to pollinators, providing nesting habitat as well as pollen and nectar sources. Native bees are perhaps in greater peril than (imported) honeybees. They just don’t have as good PR, despite flying earlier in the year and in colder, rainier, windier weather! There are 275 native bee species in Vermont (4,000 in the US). Most of us didn’t know that! There is a table of when various pollinator flowers start blooming in Vermont, to help anyone seeking to provide bee forage more of the season.

As Nancy and John produced more value-added fruit products for sale, they noticed an interesting thing: people would pay for the jam or syrup-topped snow cones, but balk at the price of the actual fruit! It’s time to move away from our expectation of cheap food (which likely derives from the history of enslaved people doing most of the farm-work in the US in the past).

Another change for the farm is to selling fruit wholesale, to wineries, breweries, cideries and soda makers. They like the big “over-and-done” sales, although selling retail direct from the farm is important for staying in touch with the public and diversifying income streams. Nancy and John point out that they could not have done all they’ve done without off-the-farm income. This is the reality for most farmers, particularly small-scale farmers. Nancy and John were fortunate in finding off the farm work that they enjoyed.

The book wraps up with an appendix of common and scientific names of plants and arthropods mentioned in the book, and an impressive twelve-page, triple-columned index. This is a book by people who really want to help us navigate our path through farming for the long haul.

Year-Round Hoophouse Vegetables slideshow, VABF Handouts

Tatsoi in the mist, November.
Photo Wren Vile

Busy Conference Season is here!

I just got back from the Virginia Association for Biological Farming conference in Roanoke. There I gave a half-day presentation on Year-Round Hoophouse Vegetables, which you can watch here:

Year-Round Hoophouse Vegetables 240m

The conference was very well-attended, and not everyone at my workshop on Friday, or the Alliums Year-Round 90 minute workshop on Sunday morning got a handout. I promised to post them here, and now I’m making good. I’m also posting the handout for the third workshop I gave, Asian Greens in the Winter Hoophouse. This rounds out the set, and gives a chance to those who went to a different workshop at that time to get a look in.

Year-Round Hoophouse Vegetables 8 pg handout 2023
Alliums Year-Round
Asian Greens in the Winter Hoophouse 2023

This coming weekend I will be venturing north to NOFA-Mass and giving a presentation on Crop Planning for Sustainable Vegetable Production.

To those who are wondering what happened to my monthly post Fruit for the Month, I postponed it. There isn’t so much fruit in January, is there?

Conference Season, cold damage update, potato yield error in my book

Conference Season

It’s busy season for conferences, so I’ll tell you about the next two I’m speaking at. You can go to my Events page to see what’s further ahead.

This weekend (January 6-8 (Fri-Sun), 2023) is the Virginia Association for Biological Farming at the Hotel Roanoke and Conference Center

VABF 2023 Conference banner

Virginia Association for Biological Farming

23rd annual Virginia Biological Farming Conference

VABF Conference INFO Home Page

The 23rd annual Virginia Biological Farming Conference is Virginia’s premier organic and sustainable agricultural conference! The Conference brings together farmers, gardeners, eaters, educators and advocates of biological and organic farming and gardening. The Conference will be held in person January 6-8, 2023 at The Hotel Roanoke and Conference Center.

The three-day Conference includes:  Full and Half Day Pre-Conference intensive workshops, 50+ sessions and workshops, presentations and panel discussions, 40+ tradeshow exhibitors, locally sourced farm meals and book signings. The Conference features a Silent Auction and networking opportunities including regional networking meetings, and the Taste of Virginia Expo & Social! 

Keynote Speakers

Dr. Elaine Ingham, Soil Food Web School

Leah Penniman, Founding Co-director Soul Fire Farm

I will be presenting a half-day workshop 8am-noon on Friday Jan 6, on Year-Round Hoophouse Vegetables

90 minute workshop Sunday January 8, 8.30 am – 10 am Alliums Year Round
90 minute workshop Sunday January 8, 10.30 am – noon, Asian Greens in the Winter Hoophouse

See the 2023 Session Summaries

Taste of Virginia Expo and Market & Social

Included in the Conference Registration and free and open to the public is the Taste of Virginia Expo & Market on Saturday, January 7, 2 – 9 PM in the Crystal Ballroom at Hotel Roanoke. Featuring sampling and sales of Virginia-crafted foods, local libations, handicrafts, and herbals. Complete the evening with music, dancing, and socializing from 8-10 PM.

Locally Sourced Meals

VABF and LEAP Local Food Hub are working together to procure the majority of our Conference food from local member farms. We look forward to supporting our member farms and enjoying delicious, fresh, local food from the farms below! All Conference Registrations include lunch and dinner on Saturday, lunch on Sunday and morning coffee and tea.

VABF logo

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NOFA-Mass Annual Winter Conference, January 12-14, 2023

Northeast Organic Farming Association, Massachusetts Chapter.

The Conference will be held at Worcester State University on Saturday January 14 and online Sunday January 15. We encourage you to make the most of the range of possibilities – i.e. tastings in person, international discussions over Zoom, tool modifications, storytelling. Creativity is welcome!

An organic lunch on Saturday is sandwiched by over 40 educational workshops for a full day of learning and socializing.

This is a valuable opportunity for farmers, gardeners, homesteaders, educators, and environmentalists to share resources and ideas to grow our vibrant organic community. We are excited to come together around this winter’s theme, “Cooperative Foodways: Building Our Future Together.”

The conference hosts 40+ workshops and draws hundreds of attendees from throughout the Northeast.

I will be giving a workshop on Crop Planning for Sustainable Vegetable Production

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Cold damage update

Bright Lights chard with cold-damaged stems.
Dec 27.
Pam Dawling

I reported very little damage to our hoophouse crops last week when it was 2F (-17C) outdoors. Since then, no plants keeled over, but some leaves are showing tan patches of dead cells, either where the leaves touched the rowcover. or where they were not properly covered. So, we have lost some leaves of senposai, a few of spinach, some on the yarrow we planted for beneficial insects. But, overall, I’m extremely happy with the good condition of our crops.

—————————————————-

Mistake about potato yields

Sorting potatoes two weeks after harvest to remove problem potatoes before rot spreads.
Photo Wren Vile

Yes made a mistake back in 2012, when I wrote Sustainable Market Farming, which I hope has been corrected in reprints since I was first notified of this in August 2019. If you have an older edition of my book, it might still have the error. In yield numbers on page 376, it says about potatoes, “Yields are likely to be 150 lbs/ac (168 kg/ha); 200 lbs/ac (224 kg/ha) is a good yield”.

“Yes, my mistake indeed! On page 45, I have the (better!) info that potatoes can yield at least 110 pounds/100 feet, or 49.9 kg/30m. I think I probably meant to write on page 376, that a low yield could be 150 pounds/100ft, which is equivalent to 11 tons/acre. In the metric system, that’s 223 kg/100m, or 24.4 tons/ha. Other sources suggest average yields could be almost twice this. And good yields, even 4 times the low numbers.

So it should say

“Yields are likely to be 11 tons/ac (24.4 tons/ha); 22 tons/ac (48.8 tons/ha) is a good yield”

That’s US tons of 2000 pounds, metric tons of 1000 kg. Or for a smaller scale, probably closer to what most of us are growing,

“Yields are likely to be 150 lbs/100ft (223 kg/100m); 200 lbs/100 ft (300 kg/100m) is a good yield”

I hope I’ve got all the conversions right.

How cold can leafy greens and salad crops survive?

Our hoophouse beds after the nights at 2F (-17C) and 8F (-13C). Looking amazing! Pam Dawling

We were luckier with the weather than many people over the weekend (12/23-12/26/2022). And so were our vegetable crops. On Friday 12/23 we prepared for a suddenly very cold night. It was very windy as we battled to stop the hoophouse windows from blowing open. We finally got some shims, a hammer and a stepladder, and wedged them closed. They stayed that way until Tuesday 12/27. We were fortunate in getting no precipitation (I hate ice!) and no power outage.

Pool noodles repurposed as draft excluders.
Pam Dawling

We fortified the doors with our rock collecting buckets, and prevented most of the under-door drafts with our pool noodle draft excluders. They have a rope running through them, which is hooked onto small cup-hooks on the door frame. We repurposed noodles that had been used as props at a party or some other kind of event. They had been covered in tube socks and had glued-on googly eyes.

Rolls of rowcover at the ready in our hoophouse.
Pam Dawling

It was a bit unnerving being in the hoophouse as it creaked and groaned in the wind. In the winter we keep rolls of rowcover ready for any night we think will be below 8F (-13C). We unrolled the rowcovers by lunchtime and laid tools on the ends nearest the doors. I was worried that if we lost power, and therefore the inflation, it would get very cold indeed in the hoophouse.

The DIY manometer in our hoophouse. (the background lines have faded). Pam Dawling

Since we last changed the plastic we haven’t managed to get the recommended 1/3” (8.5mm) pressure difference in the “bubble” between the plastic layers, compared to our normal air pressure. Mostly we don’t even get ¼” (6.5mm). The “bubble” provides thermal insulation as well as physical strength against snow or ice buildup, and strong winds.

It got down to 2F (-17C) outdoors Friday night, and Saturday didn’t warm up much. I don’t actually know what the night temperature was in the hoophouse as our recorded low temperatures don’t make sense: 14F (-10C) for four consecutive nights (Fri to Mon). I suspect we didn’t reset the thermometer correctly. Usually the hoophouse can hold 8 F (4.5 C) degrees warmer than outdoors, but not 12 F (7 C). It looks like it did, perhaps because we didn’t open it all day!

Soil thermometer in our hoophouse on 27 December 2022.
Pam Dawling

The soil is still nice and warm in there: 59F (15C). That really helps. The rowcovers are usually removed in the daytime, either pulled aside if we expect to need them again the next night, or rolled up out of the way. Most of the time they stay rolled up at the east end of the hoophouse. We appreciate not needing to deal with rowcovers most of the time! On Saturday 24th, the temperature maximum for the day outdoors was 24F (-4.5C), and we kept the rowcovers in place over the crops. On Sunday the high outdoors was 28F (-2C) so we pulled the rowcovers aside until the night. On Monday 26th the night-time forecast was benign enough that we rolled the rowcovers up. And now we get a milder spell.

Hakurei turnips with frozen yellow leaves where they touched the plastic (rowcover protected the plants). Pam Dawling

How did the crops fare? It’s not always obvious at first if a crop has been killed by cold or not, But I can now say with confidence that nothing died. The edge beds are always the coldest. The south edge bed had Hakurei turnips, delicious and notoriously the least cold-hardy turnip variety. Most of the globe of the turnip sits on the surface of the soil. You can see in the photo that some of the leaves, the ones right by the wall plastic, have been killed and turned yellow. But the roots themselves (with rowcover over them) seem fine.

Bright Lights chard with cold-damaged stems in our hoophouse north edge bed after nights at 2F and 8F
Pam Dawling

Over the other side, in the north bed, we have some Bright Lights chard, among other things. Multi-colored chards are less cold-hardy than red ones, which in turn are less cold-hardy than green ones. We know we take a risk in growing Bright Lights through the winter, but we so enjoy the sight of the short pieces of colored stems in our salad mixes that we take the risk. Some of the stems have curled over, probably on their way to dying, but the plants live on, to provide many more salads this winter! And some cooked greens too.

Some of the giant senposai leaves, where not fully protected by the relatively narrow rowcover, have developed tan dead spots, so those leaves can just continue as the plants’ solar panels until we get tired of looking at them and decide they are no longer needed.

Each winter I update my Winter-Kill Temperatures of Cold-Hardy Vegetables list, except this past spring I had nothing new to add. Outdoors, I noticed today that the tatsoi has definitely died, the Vates kale and the spinach have survived (uncovered) and the small garlic leaves don’t seem troubled. The leftover lettuce transplants have been damaged, if not killed.

Winter lettuce and other salad crops

Salad Mix freshly harvested. Lettuce-free mix!
Photo Pam Dawling

We are feasting on our winter salad mixes now, so I decided to write a post to encourage more people to grow winter salads.

Just how viable this is for you depends on your winter climate zone and your facilities. In the coldest of places with nowhere except your kitchen or a windowsill, you can grow sprouts and microgreens.

To grow sprouts, get some organic seeds, soak them in a jar, then fit a straining lid, which can simply be a piece of fabric held in place over the open mouth of the jar with a strong rubber band, or, if using a Mason jar, the metal ring part of the lid. Drain off the extra water, then set the jar on its side, with the seeds distributed evenly along the side. Rinse and drain twice a day, until the sprouts are the size you want. Here’s a couple of websites.

See How to Grow Sprouts at Home, by Beth, or Growing Sprouts at Home, by The SproutPeople

You don’t need to follow these directions word by word, but if you do, it will work. Other methods can also work. Just be sure to rinse and to drain!

The enthusiastic author of How to Grow Microgreens, Sylvia Fountaine, lays out a 6-step process and provides a video. Microgreens are basically seedlings, with stems and green seed leaves. Sprouts are mostly root and stem, as you may have noticed.

For those wanting to grow microgreens professionally, I recommend Andrew Mefferd’s chapter in his Greenhouse and Hoophouse Grower’s Handbook.  

I wrote about our Fall Lettuce Transition in my post Preparing your Hoophouse for Fall and Winter 9/28/22 – This post includes days to germination of lettuce at various soil temperatures. Here are dates when we sow lettuce for growing in various places (not just our hoophouse).

·        For outdoor lettuce I stop sowing August 29, transplant those 9/22 and expect to harvest them 12/10 – 12/31. I add hoops and thick rowcover when it gets cold to keep it growing.

Buttercrunch Bibb lettuce in December. Photo Kathleen Slattery

·        For winter growing in coldframes, I sow 9/1, 9/3, 9/5, 9/7, 9/9 and transplant 9/25 -10/8. Leaves from those plants can be harvested all winter until we need the cold frames to harden off spring transplants in mid-late February. We cover the coldframes with rowcover when it starts to get cold, then plastic-glazed lids as it gets colder, and quilts for really cold spells. These days we are more likely to direct sow spinach in the frames than transplant lettuce. It’s hardier and faster growing.

·        From September 11-17 we sow lettuce every other day in our outdoor nursery bed, to transplant in our unheated greenhouse (double glass windows, solid north wall, rarely freezes in there). We harvest those lettuces by the leaf all winter until we need to dig out the compost they are growing in to fill our seed flats in early February.

Lettuce growing in our greenhouse in November.
Photo Wren Vile

·        On September 15 and 24 we sow lettuce outdoors in a nursery bed, to transplant in our hoophouse 10/15 and 10/24. Those lettuces will feed us all winter, 11/16-3/1, if we simply harvest the outer leaves, rather than cut the head.

Green Panisse and red Revolution lettuce in our hoophouse in November.
Photo Pam Dawling

·        On October 23 we start sowing lettuce mix in the hoophouse. We sow successions of baby lettuce mix directly in the soil 10/24, 12/31, 2/1, 2/15. The last one, on 15 February, will be for harvest starting mid-March, and ending in May when it gets too hot. By then we should be happily harvesting juicy lettuce heads outdoors and will have lost interest in the lettuce mix. We like Fedco’s 2981LO Lettuce Mix OG or Johnny’s Allstar Gourmet Lettuce Mix #2301. For those with challenging growing conditions, both companies offer other specialized selected mixes. 1 oz (28gm) of seed sows about 600 ft, (200m) 

Baby lettuce mix in our hoophouse in winter.
Photo Twin Oaks Community

·        We sow “filler leaf lettuces” in our hoophouse 10/23, and 11/9, to use for gap filling (replacing casualties). 1/25 is our last date for filling any gaps in the hoophouse beds with lettuce plants. After that, we fill all gaps with spinach plants.

Short rows of filler greens in the north edge bed of our hoophouse in December.
Photo Kathleen Slattery

·        So, we have different “stop-dates” for the different types and locations, but no complete Lettuce Stop-date.

o   8/29 Last date for sowing for outdoor row-covered lettuce

o   9/9 last date for sowing to transplant in coldframes

o   9/21 last date for sowing for planting in an unheated greenhouse.

o   9/24 last date for sowing for planting into a double-layered hoophouse

o   11/9 last date for sowing “filler leaf lettuces”

o   2/15 last date for sowing baby lettuce mix in the hoophouse.

How should people not in central Virginia calculate their own stop dates? Using the same numbers as above for the various types and locations:

  1. ​Figure out how late in the year it’s worth having lettuces outdoors. When does the temperature drop to 20°F (-7°C)? Stop sowing for outdoors 3-4 months before then. (Our 8/29 sowing is harvested by 12/31, but our 8/20 sowing is harvested by 11/25). It’s worth experimenting to find which date works best. Outdoors, I have found that lettuce may survive an occasional dip to 10°F (-12°C) with good rowcover. Consult your Extension Service and the website WeatherSpark.com. Fill in your location and look at pages of useful info about the weather where you are.
  2. Figure when your coldframes get down to say 15°F (-9°C). This might be when the outdoor night-time low is 10°F (-12°C), lower if you have a well-insulated coldframe. We have some old quilts to roll on top of our coldframe on nights below 15°F (-9°C). Perhaps lettuce won’t make it all the way through winter in a coldframe in your climate. If so, be prepared to clear the plants when it gets too cold. Calculate back to figure when to sow – allow 4 months to get full sized lettuces.
  3. Figure when your solar double-paned-glass and masonry wall greenhouse gets down to ° (-9°C), or add a small heater with a thermostat to keep it warmer than that. Calculate back to the sowing date, allowing for the fact that plants grow quicker in a greenhouse than outdoors or in coldframes. Maybe allow 3 months.

    Our greenhouse with young lettuce transplants in early October.
    Photo Bridget Aleshire
  4. As far as daylight goes, on 9/24 everyone everywhere is pretty much getting the same amount wherever we live. With a hoophouse, the goal is to grow plants to harvestable size by the time you no longer have lettuce from outdoors (refer to #1). It probably only takes 2 months to grow a lettuce big enough for leaf harvest in a double layer hoophouse. Just be sure not to over-harvest in the winter. We have had lettuce survive a double layer hoophouse temperature of 10.4°F (-12°C) without any rowcover (sometimes called an inner tunnel), and -2.2°F (-19°C) with.
  5. At this point calculations switch to what happens after the Winter Solstice. When do you plan to start harvesting your first outdoor lettuce again? Aim for a two-week overlap with both hoophouse and outdoor lettuce available in the spring. Work back from your hoophouse harvest end date to find the last worthwhile sowing date for filler lettuces. Because lettuce bolts easily when it gets warm in spring, play it cautious. We plan to start outdoors 4/15. We stop transplanting lettuce in the hoophouse 1/25, 2 1/2 months before then. Sowing filler lettuce too late is not really a problem – you can cut it as baby lettuce. But avoid transplanting it just to have it bolt.
  6. If your climate is cold, or you don’t mind only getting one or two cuts from baby lettuce mix, you can carry on sowing it until the soil temperature reaches 86°F/30°C (max temp for lettuce germination). If it is warm, do be sure to water often, so the lettuce doesn’t turn bitter. Otherwise look to you first outdoor lettuce and clear the baby mix when the outdoor crop is ready.
Beautiful baby lettuce mix in our hoophouse in February.
Photo Wren Vile

See my post Lettuce All Year in a Changing Climate 8/31/21. It includes links to all my Lettuce of the Month series, and includes my slideshow Lettuce Year Round and our 2022 Lettuce Varieties List, to help you choose varieties we recommend for different times of year.

For ideas on mixing various crops in winter salads, see Making Salad Mix 10/31/17 and Fast Growing Vegetables 3/24/20. Winter salad mix is also known as mesclun or spring mix (even though we are growing it in the winter). Spinach and many brassicas grow faster than lettuce in cold weather, and make delicious salads.

Bulls Blood Beet leaves
Photo Bridget Aleshire

Also, check my Asian Greens of the Month posts. This post from April 2018, includes at the end links to each of the series. Many Asian Greens make great salad crops. The frilly mustards featured in this post are a good example.

For information on the temperatures that many crops will die at from cold, see Winter Kill Temperatures 2021. I was updating this list each spring. 2022 seems to have slipped by. I don’t think I had any new information, as the winter wasn’t extreme (although we had a long and memorable power outage!).

 

Flowers Against Aphids – The Research Continues

I missed Giving Tuesday, but I do have a donation button for anyone who is able to support my work! I appreciate the help, as blogposts don’t exactly pay for themselves.

September-sown Borage flowering in our hoophouse in January. Photo Pam Dawling

It’s late November as I write this. Starting last fall (2021) we sowed a range of flowers to attract beneficial insects, to plant in our hoophouse in hopes of reducing the early spring aphids. Aphids can get out of control in early spring in our greenhouse and hoophouse, as they become active before their native predators, such as ladybugs, emerge from hibernation. In January we get bad aphids on the lettuce and, of the flowers we planted to attract beneficials, borage was the only one flowering. It was not enough. We did three sprays of soapy water at 5 day intervals to kill the aphids. We also have a particular problem in our hoophouse and in our greenhouse on the eggplant, pepper and tomato transplants from mid-April to mid- to late- May depending when we manage to get them under control.

Young eggplant struggling against lots of aphids.
Photo Pam Dawling

Most flowers in our trials were annuals, and they flowered and died. We still have four yarrow plants and one bushy shungiku. Shungiku is Glebionis coronaria, (formerly called Chrysanthemum coronarium, Ismelia coronaria, Xanmthophthalmum coronarium, or Pinardia coronaria), and commonly called Crown Daisy. Most chrysanthemums are perennial with poisonous leaves, but shungiku is an annual. Our plant seems not to know this.

September-sown shungiku (chrysanthemum greens) in January.
Photo Pam Dawling

Shungiku is the eastern Japanese name for the edible chrysanthemum, also known as “garland chrysanthemum” or “chop suey greens” in English. It is known as “Kikuna” in western Japan, “tong hao” in Chinese, ssukgat in Korean and cải cúc or tần ô in Vietnamese. There are various colors of flowers. Ours are yellow, not banded with other colors. We bought seed from Small House Farm. Bevin Cohen says it does attract bees, butterflies and predatory insects, and would probably do well in the winter hoophouse, and could be provoked into bolting early in the spring.

After our research and trials, we decided it isn’t worthwhile growing the annuals, as they didn’t flower when we needed them (except this shungiku!). We might try borage again, as it was quick to flower last year, and other people have done well with borage. Ours died. We also decided (as recommended by a reader) to leave some overwintered brassicas to flower. We are starting to find bolting mizuna, so that may be perfect.

Bolting mizuna in our hoophouse
Photo Pam Dawling

Two of the four yarrow plants have flowers (in November) and we will keep them. Having perennials seems a good way to get flowers in early spring. These plants were too young to flower last spring. We still have some seeds of the perennial phacelia, so we could try that again, although perhaps it isn’t cold-hardy enough.

Anti-aphid yarrow flowering in our hoophouse in late November, 13 months after sowing. Photo Pam Dawling

If you want to read the trials and research that led us to this point, see two posts from February 2022: More on Insectary Flowers. It was too cold for predators in early February, even with enticing flowers. Ladybugs showed up in late February and we had borage flowers for them, but no other flowers. We had sowed at the very beginning of September and the very end of October. After that, we started more flowers in our greenhouse on February 1. We noticed that plants in pots dry out very fast in the hoophouse, and they have to be hand-watered, as the drip tape doesn’t do it. It’s probably better to get the flowers in the ground in the hoophouse and greenhouse as soon as they are big enough.

Earlier in February, I posted Growing flowers to attract aphid predators in early spring

I listed aphid predatory insects such as ladybugs, lacewings, aphid parasites, damsel bugs, braconid wasps, rove beetles, syrphid flies, and spined soldier beetles, as are attracted to plants with small flat open flowers, like alyssum, dill, yarrow, buckwheat, sunflowers, and cosmos.

On a big scale this is known as Farmscaping, and you can read about it in a publication from ATTRA; Farmscaping to Enhance Biological Control . You can use this publication to make a specific plan to tackle particular pests. Ladybugs are a good general help because they eat the eggs of many different pest species.

A ladybug on the leaf stem of a sunflower planted to attract beneficials. Photo Pam Dawling

Organic Integrated Pest Management involves tackling pest problems one step at a time with ecologically-based practices, starting with actions chosen to reduce the chances of the pest ever getting a grip on your crops. You can find various listings of steps online and in print. They are all in basic agreement – start with prevention, follow with avoidance, and finish with pest-killing if needed. I recommend the ATTRA Organic IPM Field Guide. Each of the 22 pages is a poster, complete with good photos and concise clear info.

eOrganic has many articles on Insect Management in Organic Farming Systems that explain ways to tackle pest problems with ecologically-based practices, starting with actions chosen to reduce the chances of the pest ever getting a grip on your crops.

A pepper leaf with tiny aphids.
photo Pam Dawling

That post describes the lifecycle of aphids, starting in spring with eggs hatching into wingless females that give birth via parthenogenesis to more females. Within a week, one female can produce 100 clones, which can repeat the process at the age of one week.  This continues until adverse weather or predators trigger production of a generation of winged female aphids that moves to new plants. Later in summer male aphids are born and females lay fertilized eggs that overwinter on host plants, to hatch the following spring.

There is a chart in the post, giving details of the flowers we chose, where we found the seed, and which months we decided to plant them in.

Our first sowing, in September, was of borage and shungiku (Chrysanthemum greens) only. We thought having some flowering plants in large pots would enable us to move them to the trouble spots, but plants in pots dry out too fast. The borage flowered with pompom-like clusters, much more compact than spring outdoor borage does.

Anti-aphid flowers yarrow in pots in January (October sown)
Photo Pam Dawling

The second sowing, in late October, included Meadowfoam, Tidy Tips, Phacelia and Yarrow. Those plants were still small at the beginning of February. No flowers, no help against January lettuce aphids.

The third sowing was February 1, and included borage, shungiku, Meadowfoam, Phacelia, Tidy Tips and yarrow.

The September-sown borage and shungiku both had trouble with cold temperatures during January – three non-consecutive nights at 10F (-12C). Some of each got cold-damaged.

By February, no beneficial insects had been seen on the borage flowers, and no aphids had been killed as a result.

Shungiku in November with a bee.
Pam Dawling
Shungiku with spider, in November. Pam Dawling
Shungiku with a fly in November. Pam Dawling
This looks like a leaf-footed bug on the shungiku in November. Not good news to have this pest around! Pam Dawling

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The background to these 2022 trials included a lot of research. In July 2021 I posted Controlling Aphids in Early Spring

Climate change is making the problem worse: for every 1degree Celsius rise in average temperature (about 2 F degrees), aphids become active two weeks earlier.

Organic Integrated Pest Management

I have a blog post about our organic integrated pest management, a 7 step method of pest management which starts with actions least harmful to the ecosystem, only employing biological controls such as botanical sprays and selective pesticides if necessary after all other steps have been insufficient.

Pepper plant with aphids and ants farming them.
Photo Pam Dawling

Applying these principles to dealing with early spring aphids

  1. Prevent infestation Control ants (which farm aphids for their sweet excretions). Try repellents, or trap crops of nasturtiums.
  2. Cover or protect physically with fine mesh netting.
  3. Provide habitat for natural enemies. Plant for a continuous supply of insect-attracting blooms, that flower early in the year and attract predators such as ladybugs, lacewings, syrphid flies (hoverflies), damsel bugs, big-eyed bugs, and spiders. Grow early flowers with pollen and nectar they can use as alternative foods. Sow seed in fall for earliest bloom.
  4. Monitor crops at least once a week
  5. Introduce natural enemies: We do have an aphid parasite in the hoophouse as we do find mummies, but not enough to control an aphid outbreak in spring. Parasitic wasps for aphids include Aphidus colemani from Arbico Organics; Aphidus ervi from Arbico; a predatory gall-midge, Aphidoletes aphidomyza, (cost $125 including shipping per week, perhaps $375 total); Green Lacewings (more affordable); Ladybugs, notorious for flying away.
  6. Hand pick and kill. Handpicking aphids is likely impossible, so blast them off the plants with a water jet from a hose.
  7. Use biological controls. Failing success with the methods above, a soap spray can be effective, although aphid predators will also be harmed. We use 3 Tablespoons (15 ml) per gallon (3.8 l) of biodegradable Murphy’s Oil Soap, in a sequence of 3 sprayings 5 days apart.

Also see that post for details about Tidy Tips (Layia platyglossa), a spring flowering wild annual in the aster (sunflower) family; Meadowfoam (Limnanthes douglasii), a fast-growing bushy annual commonly known as poached egg plant and Douglas’ Meadowfoam; Baby blue eyes (Nemophila menziesii), a low spreading, shrub-like annual; Borage, a warm-season annual, taking only about 8 weeks to flower from sowing; Sweet Alyssum, a small annual; Shungiku, described above. We considered, but did not plant two biennials: Dill and Angelica, as they sound quite large. The perennials we chose, are also large (30” tall, or much more, and might need staking), but the advantages of having permanent working plants won us over. Yarrow is hardy to zone 5. Common Yarrow (with flowers that range from white to red) is hardy down to zone 3. It attracts an array of beneficial insects. Phacelia is particularly useful in early spring if it has overwintered as it is an early pollen source for bees coming out of hibernation. Sow in the fall for early spring blooms But it winter-kills at approximately 18˚F (-8˚C), and I think that’s what happened to ours. We also considered Fennel, Foeniculum vulgare (common fennel) but it blooms from mid-summer to frost. Too late and too tall for our goal of attracting spring aphid predators in the hoophouse. Coyote bush, (Baccharis pilularis), also called chaparral broom, is a native shrub related to sunflowers, that sounds way too much of a space hog. And Dandelions – I just couldn’t bring myself to risk planted this sturdy weed in the hoophouse!

That post also includes details of natural enemies you can buy, and how to make a soap spray if none of those efforts work. Also there you will find the approach we decided on as the Best Options for our Hoophouse and Greenhouse in April and May

November photo of shungiku flowering in our hoophouse alongside Yukina Savoy, senposai and Hakurei turnips. Pam Dawling

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Way back in July 2016, I posted  Insectary Flowers to Attract Beneficial Insects

This post covers insectary flowers outdoors and in, at various times of year. At the end of April we sow several plug flats of different flowers to plant out in Insectary Circles at the ends of our outdoor raised beds.

See my July 2017 Mother Earth News post Insectaries: Grow Flowers to Attract Beneficial Insects In late May or early June, we transplant IPM

flowers in our outdoor Insectary Circles in the vegetable garden to attract pollinators and pest predators. We use circles cut from plastic buckets to surround these clusters of flowers so that inexperienced helpers don’t pull them out as weeds.  We use a combination of sunflowers, dill, borage, cosmos, calendula, tithonia (Mexican sunflowers), zinnias.

Cindy Conner suggested leaving parsley and celery plants to overwinter and flower early.

Events I’m speaking at this fall and winter

 

At CAFF (The Center for Arkansas Farms and Food) in September I presented High Tunnel Season Extension

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CAFF - Extend Your Growing Season into Colder Weather with High Tunnels
I’m spending October home on the farm, preparing and planting the hoophouse with winter crops. Meanwhile I’m applying to speak at quite a few sustainable agriculture conferences and preparing slideshows, handouts and talks. I’m going back to in-person conferences. We have very limited Wi-Fi in this part of rural Virginia and video-conferencing is just not possible. I managed to make some recorded narrated slideshows during the pandemic and I picked up more writing work. But there is an undeniable something I get from in-person conferences!

In the past year I’ve been at two in-person events: The very safely and carefully orchestrated PASA conference back in February, and the September CAFF presentation, half of which was outside touring the farm and half in a large airy lecture room. Now I’m lining up quite a few conferences. Go to my Events page on this website to get all the details, including links to register. Hope to see you at one of these:

I will be facilitating the Farmer Roundtable: Working Through Production Challenges on Saturday, November 5, from 1:30 – 2:45 pm with time to linger afterwards.

CFSA 2022 Conference banner

I will be presenting a 75-minute workshop on Spring and Summer Hoophouse Use, especially how to manage extreme heat and diseases in hot and humid climates.

Tennessee Local Food Summit logo
  • January 6-8 (Fri-Sun), 2023, Virginia Association for Biological Farming is hosting the Virginia Biological Farming Conference, Hotel Roanoke and Conference Center. Conference INFO Home Page

I hope to be presenting a half-day pre-conference session on Friday January 6, on Year-Round Hoophouse Vegetables. Also maybe a regular length session during the main conference.

VABF 2023 Conference banner
  • January 14, 2023 (Saturday), NOFA-MASS Annual Winter Conference. Northeast Organic Farming Association, Massachusetts Chapter. https://www.nofamass.org/conferences/ Worcester State University on Saturday January 14 and online Sunday January 15. I hope to give a presentation on Saturday.
  • February 8-11, 2023 (Weds to Sat 2.30pm), PASA 2023 Sustainable Agriculture Conference. Lancaster Marriott Hotel and Conference Center, 25 S Queen St, Lancaster, PA. https://pasafarming.org/conference/

I will be presenting two 60 min or 75 min workshops:

Alliums Year-Round (Brand New!)

Crop Planning for Sustainable Vegetable Production.

Virtual Conference: January 17–19

Feb 25-26, 2023, Organic Growers School Spring Conference, Mars Hill University, Asheville, North Carolina

Along with Ira Wallace, I will be presenting a half-day (3 ½ hours) workshop Year-Round Gardening 

The workshop will be on Saturday and repeated on Sunday

Organic Growers School logo

One Folk School Road, Brasstown, NC 28902

I will be teaching a week-long course, Growing Vegetables Year Round

Campbell Folk School logo

I will be presenting two 60 minute workshops, one each day

I will be presenting two 60 minute workshops, one each day. Different workshops from the Kansas Fair.

Check back on my Events page often, as events and details are firming up

Hoophouse Winter Schedule Tweaks and Improvements

I’m always on the lookout for ways to pack more crops in, get higher yields, reduce or at least spread the workload. All while nurturing healthy soil and organic food that people enjoy.

Tweaking the Salt Wash-Down Dates

Using a lawn sprinkler to wash down the salt build up in our hoophouse. Photo Pam Dawling

I wrote about Preparing your Hoophouse for Fall and Winter on September 28. I belatedly realized that in my hurry to publish the post I let some out-of-date info slip in. We don’t do our fall salt wash-down in November any more – we prefer early October, while it is still warm enough for the plants to be improved by extra water, rather than drowned and miserable. We have switched from two days in the spring to three, as we think two days wasn’t quite enough water to get all the salt back deep in the soil profile. We had ambitions of doing three days in the fall as well, but I can tell you now, from experience, that we can fit in two days but no more.

I’ve described how we broadfork and rake all the beds in the fall, and the amount I can do in one day (along with all the other tasks) is 1/3 of a 96ft x 4ft (29m x1.2m) bed. That human limitation, and the logistics of crop rotation and planting dates, leaves a small window between preparing the first three beds to get planted (9/6-10/6), and the remaining four (10/10-10/24). It really doesn’t work well to broadfork and rake saturated soil! It’s better to have a few days for the water to soak in. So, we are satisfied with two days of salt wash-down in fall, for the time being.

Catch Crops

Mid-October photo of September-sown tatsoi and August-sown Tokyo bekana. Fast-growing crops make good use of small windows of time.
Photo Pam Dawling

Last fall I noticed that some areas of some of our beds were idle between being prepped and planting dates in November and December.  I hate to waste prime real estate like hoophouse bed space, So this year when we planned our bed layout, we herded all the little late sowings into one bed with the intention of finding some fast-growing crops to put in that space first. We also managed a more rational layout in each bed, planting the various crops in chronological order from the east end to the west.

Next, I researched what we might grow ahead of the main crop. There are some unknowns here. We have numbers of days to maturity for crops in ideal conditions (nice warm spring temperatures), but we are heading into colder temperatures and shorter days. So it might not work out as we hope. However, given our fondness for salad mixes, anything we have to pull up immature will still be eaten and enjoyed!

Salad Mix freshly harvested.
Photo Pam Dawling

The bed in question was all ready to plant on September 30. The areas I could see for catch crops included 11/9 “filler” spinach and filler lettuce, 11/15 tatsoi #2, 12/7 lettuce mix #2, 12/18 mustard salad mix, and 12/20 radish #5.

I decided to put the 16ft (5m) of areas for November 9-15 sowings (39-45 days to go) into 45day Tokyo bekana and the 18ft (5.5m) of areas for sowings after December 7 (79 days available at that point) into 60day Cylindra beets. The Tokyo bekana came up very quickly, and I expect it will be destined for salad greens, which will be very useful as our outdoor lettuce is waning and we’ve just had a patchy frost (early for here) – the colder weather will slow crops down.

Young Cylindra beets.
Photo Wren VIle

The beets have still not come up 9 days later, and the soil is 60F (15.5C). I’ll check again tomorrow. 10 days should be long enough with soil at that temperature. My niggling worry is that the salt wash-down has drowned the seeds. See Root Crops in August. If they are not up at 10 days, I think I will hoe the area and resow with something quicker – perhaps tatsoi (45 days). I was disregarding tatsoi because it will bolt in January. Umm, but this is a catch crop, that we’ll need to pull up in early December – January isn’t even on its calendar!

Carrots out! Cress in!

Belle Isle Upland Cress from Southern Exposure Seed Exchange

Last winter we grew a small patch of carrots because one of the crew really wanted to try them in the hoophouse. I wasn’t a fan because carrots are so slow-growing and provide only one harvest (usually). But I am a fan of democracy and participation, so we grew carrots. We could have harvested them sooner than we did and planted something else (in my opinion), but there they sat all winter.

Oh yes, about that “usually”: you can eat carrot tops and I have used finely chopped carrot leaves as a garnish. A major brand of crackers has carrot tops as one the herbs in their Herb Crackers. Read the small print!

This fall, as we planned our crops, I said I’d prefer not to grow carrots again, but I was out-voted, and hence we sowed carrots. Now those crew members have left, and I gave the evil eye to the carrots. I’d just read an interesting article about nutrient-dense vegetables, and learned that The 5 Most Nutrient-Dense Vegetables Based on Science are watercress, Chinese (Napa) cabbage, Swiss chard, beet greens, and spinach. We’re growing all the others, but no watercress. For the next-best thing, I wanted to try land cress/Upland Cress in our winter hoophouse.  So I hoed off the little carrots and sowed Creasy Greens Upland Cress and Belle Isle Upland Cress from Southern Exposure. They take 50 days to maturity (in spring) and I note:

“The yellow blossoms help nourish ladybugs, syrphids, and other beneficial insects”

So I plan to let some flower in spring for the beneficial insects.

Creasy Greens Upland Cress from Southern Exposure Seed Exchange

Flowers for beneficial insects

September-sown shungiku (chrysanthemum greens) in January.
Photo Pam Dawling

Last year, one of our trials was a collection of annual flowers to attract more pollinators into the hoophouse. None of the ones we tried seemed to do much, except for one shingiku (chrysanthemum greens) which is still flowering! Readers suggested I’d do better to just let some winter brassicas flower instead of growing special flowers. So upland cress might become part of our solution for that! We’re also growing a perennial, yarrow, to attract beneficials.

Shungiku chrysanthemum greens.
Photo Small House Farm

The other hoophouse tweaks on my list are more for spring and summer, so I’ll leave those for another post.

Preparing your hoophouse for fall and winter

December lettuce and spinach in our hoophouse. Photo Wren Vile

Recently I traveled to Fayetteville, Arkansas to give my presentation Extend Your Growing Season into Colder Weather with High Tunnels. Run the mouse over the slide and click on the lower left.

CAFF - Extend Your Growing Season into Colder Weather with High Tunnels

We are getting ready for fall and starting to plant our winter crops in the hoophouse.

I have written about transition to winter crops here: Planning and Growing Winter Hoophouse Vegetables (August 16, 2022). This post includes a bed plan, and links to lots of related posts, such as selecting and planning winter crops, bed prep, direct sowing and transplanting, and then caring for the crops, optimizing use of the space, harvesting, and what to do if something goes wrong,

Fall Lettuce Transition

From September 11-17 we sow to transplant in our greenhouse, and on September 15 and 24 to transplant in our hoophouse. This is our fall transition and I’ll write about that when the time comes.

On September 15 and 24, we sow leaf lettuces and romaines in an outdoor nursery bed. We transplant these into our hoophouse at 10” (25 cm) spacing. This is a bit closer than the 12” (30 cm) spacing we use outdoors. We will harvest outer leaves from the hoophouse lettuce all winter, so the plants won’t get as big as they do outdoors.

Beautiful baby lettuce mix in our hoophouse in February.
Photo Wren Vile

On October 23 we start sowing lettuce mix in the hoophouse. Baby lettuce mix can be ready in as little as 21 days from mid-spring to mid-fall, longer in colder weather. Our first sowing will be harvestable form 4 December to 15 May if we’re lucky, although if it gets too hot, this planting will get bitter and we’ll need to pull it up.

Baby lettuce mix is a direct-sown cut-and-come-again crop, the plants regrow and can be harvested more than once in cool seasons. We sow 10 rows in a 4’ (1.2m) bed, 4.5” (11cm) apart. Weed and thin to 1″ (2.5 cm). When 3″–4″ (7.5–10 cm) tall, cut 1” (2.5 cm) above the soil. Gather a small handful in one hand and cut with using large scissors. Immediately after harvesting, weed the just-cut area so the next cut won’t include weeds. Rake after harvest with a fine leaf rake to remove outer leaves and cut scraps. If you want to make more than one cut, you will need to remove anything that isn’t top quality salad while you can see it. Larger scale operations have harvesting machines.

We make four or five sowings of baby lettuce mix, sowing our last one on 15 February, for harvest starting mid-March, and ending in May when it gets too hot. By then we should be happily harvesting juicy lettuce heads outdoors and will have lost interest in the lettuce mix.

The soil temperature range for germination of lettuce seeds is 35-85°F (2-29°C), with 40-80°F (4-27°C) being the optimum range and 75°F (24°C) the ideal. At 41°F (5°C) lettuce takes 15 days to germinate; at 50°F (10°C) it takes 7 days; at 59°F (15°C) 4 days; at 68°F (20°C) only 2.5 days; at 77°F (25°C) 2.2 days. Then time to germination increases: 2.6 days at 86°F (30°C); after that it’s too hot.

Removing Shadecloth from our Hoophouse

We are now removing our shadecloth. Normally we would have removed the shade cloth in mid-September, or at least by the Equinox, but this year we are delayed a week. After 15 years with our initial piece of shadecloth we ordered a new piece. Well, we ordered two new pieces, because we mistakenly ordered a piece only half long enough. We bought a matching piece for the other half, and this winter we are going to sew the two pieces together with nylon twine, because the ends of each piece roll back, leaving a central gap about 6 feet long by September. Measure twice, order once!

Our hoophouse with two pieces of shadecloth (by mistake). Photo Pam Dawling

Before next spring we need to replace quite a lot of the hooks the shadecloth ropes attach to. Next time we replace the big plastic we also need to replace the baseboards, as they are rotting and not holding the hooks well.

My post Fall hoophouse bed prep and shadecloth removal includes spreading compost, broadforking, and a step-by-step guide to hoophouse fall bed prep.

Also see September in the Hoophouse for more about removing shadecloth

A reader passed on this tip:When I ordered shadecloth for my hoophouse, I overshot each end by ten or twelve feet. We stake that out on either end, using six-foot T-posts, to give us a shaded area where air moving into the hoophouse’s open ends can be cooled before entering the structure. Every year in July and August, I’m grateful we did.”

Washing Down the Salts in the Hoophouse

Effects of excess soil salt levels on crop foliage.
Photo Rose Ogutu, Horticulture Specialist, Delaware State University

Next week we will leach the salts that have risen to the surface of the soil and dried out there. My book The Year-Round Hoophouse has a whole chapter on recognizing, monitoring and reducing salts that have built-up in the hoophouse, and reducing the likelihood of problems in the future. There is also a chart of salt tolerance of various vegetables, so you can choose what to grow while you remediate your soil. Here I’ll just give a very short intro, in three slides. Click in the lower left of the first slide to move to the next one.

Salt Build-up

Closing Hoophouse Doors and Windows at Night

We are starting to close the doors at night when the temperature looks likely to drop below 50°F (10°C) outside. We had to trim down the grass to be able to push the doors to. We had to re-drill the holes the door-bolts (“cane bolts”) go down into. The doors have been wide open all summer.

View through the hoophouse doors in December.
Photo Kathleen Slattery

In fall/winter/spring, if night time outdoor low temperatures will be below 40°F (4.5°C) here, we close the windows as well as the doors.

See my post Hoophouse Sliding Doors if you might want to replace your doors with sliding ones.

One of the sliding doors on our hoophouse.
Photo Pam Dawling

Be Ready for Winter

See my post Dealing with winter weather in your hoophouse (Jan 2022). Be ready to deal with snow and strong winds, extra cold temperatures, and holes in the plastic letting cold air in. If you have a double layer hoophouse, the air inflated between the layers adds strength to the structure, as well as thermal insulation. Holes are bad news.

Hoophouse snow scraping tool on a telescoping painter’s pole. Photo Pam Dawling

Winter Kit

  • SnoBrum and telescoping painter’s pole
  • Hat with visor
  • Long-handled broom with bristles covered with a towel or some bubblewrap
  • Rowcover or inner tunnels
  • Some spare plants, back-up plans or a list of fast-growing crops to replace disasters with successes.
  • PolyPatch tape for fixing holes in the plastic
  • Gorilla tape for fixing many problems
  • Pond noodles or other draft-excluding sausages if your doors let air under them
  • Perhaps some sturdy poles or 2x4s to help support the roof in case of very heavy snow.
  • Hot chocolate/tea/coffee for when you get back indoors.
Plan D: seed flats in our hoophouse on Oct 16, a late attempt to make up for things that went wrong!
Photo Pam Dawling