Year-Round Growing on the Farm and Garden, starting now

At the Organic Growers School Conference, Ira Wallace and I co-presented a half-day workshop (twice!). I uploaded the slides as a pdf on SlideShare.net, and here they are.

Those who start early in “spring” (late winter) might get earlier crops, but when is it worth it?

Some crops are just not going to thrive if you start too soon: cucumbers, peppers, and even tomatoes, for example. Make sure you can provide conditions that meet the minimum temperature requirements for these tender crops. See my book Sustainable Market Farming, for all the details. We used to start these tender crops earlier than we do now. March conditions have become more unreliable, often colder.

If you already have a place to grow protected crops, or you are experienced with rowcover and have plenty on hand, then the signs are good. Crops can be started earlier in a greenhouse or hoophouse (or even on a kitchen windowsill) than you can sow them outdoors. When the plants reach a good size, harden them off and then plant them out in a mild spell, with rowcover for the first couple of weeks. Pay close attention to weather forecasts.

Our greenhouse full of seed flats and sunshine in March.
Photo Twin Oaks Community

“Hardening off” is a process of acclimating your plants to colder, brighter, breezier conditions, so that they won’t suffer when they are transplanted. If you have only a small number of plants, or of flats, you could actually bring them back indoors every night and set them out every morning for 10-14 days. Growers with lots of crops to harden off will make use of a coldframe. Depending on the actual temperature (or the expected night-time low) we might leave our plants uncovered, use rowcover, top the rowcover with transparent lids (“lights”) , and if it’s going to be really cold, quilted covers, weighted down with wood beams if it is the least bit windy.

Our coldframes and greenhouse at Twin Oaks. Photo Twin oaks Community.

After two weeks of hardening off, look for a few days of mild, calm weather to plant them out in the garden. Water the plants well the day before transplanting, and again one hour before transplanting. This allows the cells of the plants to fill up with water, enough to tide them over the period of “transplant shock”.

Even the most skillful of us end up doing some damage to the roots of transplants, and that means the plants have to regrow some lateral roots and root hairs before they can pull in water at the rate they were doing before your ministrations. As you transplant, avoid touching the roots of the plants. Our fingers damage the root hairs.

Okra seedlings in a Winstrip tray in the greenhouse.
Photo Kathryn Simmons

A way to minimize the root damage is to use soil blocks or Winstrip plug flats. These methods are more expensive in time or money than open flats or bare root transplants, but they allow the roots to get “air-pruned” as they grow. When the roots reach the air at the edges of the blocks, or at the vertical slits on the sides of the Winstrip cells, they stop growing, rather than circle around the cell, causing the plant to get root bound. Secondly, these tools work by helping the roots and compost form a coherent block, one that holds together as you pop it into the hole you create in the soil.

Speedling flats are styrofoam flats with tapered cells, and it is possible to slide the plugs out (or gently pull them out) with little damage. Regular cell packs (4-packs, 6-packs etc) can be encouraged to release their transplants by squeezing them at the base of a cell, while holding the pack sideways. Then spread your fingers over the compost around the pant, invert the pack and hopefully the plant and its compost stays as an item, with your fingers either side of the stem.

Transplanting spinach from a Speedling flat. Butter knives are the tool of choice for easing the little wedges out of the tapered cells.
Photo Denny Ray McElya

Hold the plant with one hand by a seed leaf, or if you have to, by the stem. The seed leaves are disposable, stems and roots are not! Hold the plant at the right height, usually with all the stem below the leaves in the ground and all the leaves above ground. Once the plant is in the ground at the right height, hold it there and use the other hand (maybe with a trowel) to push in soil to fill the hole. Firm the soil down quite well, pulling in more soil as needed to leave a level surface. You don’t want the plant to be in a divot, where water can accumulate.

About the degree of firmness: you are aiming to make good contact between the soil and the plant roots, so the roots are not in air pockets, but rather can suck in water from the between soil particles. Don’t firm so hard that you expel the air from the soil and make what feels like concrete the next day. With cabbages, I was taught to firm enough so that if you then grasp a leaf and pull, the leaf tears off, rather than pulling up the whole plant.

Plant for 20-30 minutes, then pause and water in each of the new transplants by hand. Some people will bring a watering can along the row and water each one, one at a time. I prefer to do little batches. At the end of you transplanting session, water the whole row or bed again. try to avoid having piles or dishpans of plants with roots exposed to the air. Definitely don’t take a tea break if you have exposed plants.

Cover with rowcover if needed, or shadecloth if the weather is very bright and sunny. This will just be for a few weeks, helping the plants recover from the transplant shock, and biding time while spring warms up.

If it doesn’t rain, water again the next day (day 2), then on days 4 and 6, then twice a week, then once a week forever after that, until harvest is completed.

A bed of young transplanted lettuce.
Photo Wren Vile

More on Blueberries; Crop Planning Slideshow

Admiring a cluster of blueberries.
Credit Marilyn Rayne Squier

More Resources on Blueberries

Since my post on Fruit for the Month of February, I have found some more really good resources on blueberries

Blueberries are easy to grow if conditions are right. They are a popular choice with organic growers, because they don’t need any pesticides to produce a good crop. They do, however, need annual pruning to be sure of a high quality crop. Pruning also keeps the bushes at a height easy to harvest from. Pruning is done during the dormant season, usually between December-early March in the Piedmont.

Some people are reluctant to prune because it does remove some of the flower buds and reduces berry production for that year, but if pruning is not carried out, berries become smaller each year and the health of the bushes declines. Pruning is an investment in the long-term success of your plants!

The Growing Small Farms website links to many how-to videos and fact sheets, with diagrams and photos. There are excellent resources on pruning and blueberry production in general. Everything you need to know about pruning blueberry bushes!

Side-by-side comparison of blueberry bushes before and after pruning. Slide by Bill Cline
Read more at: https://growingsmallfarms.ces.ncsu.edu/2023/01/february-is-a-great-time-to-prune-blueberries/

Another good resource is this article in the Agricultural Research Service newsletter

More People are Getting the ‘Blues’

By Scott Elliott, ARS Office of Communications.

Here is some recent information on blueberry research. New varieties, and a disease to watch out for.

Researchers at the Horticultural Crops Production and Genetic Improvement Research (HPCGIR) Unit in Corvallis, Oregon, are developing new cultivars of not just blueberries, but also blackberries, red raspberries, black raspberries, and strawberries to meet the particular needs of growers in the Pacific Northwest. Also useful to those in other areas.

“We focus on improving the shelf life of fruit so that it reaches consumers with consistently better texture and flavor,” said Claire Luby, plant geneticist with HCPGIR. Perhaps a large challenge for Luby and her colleagues is developing a cultivar that is resistant to a disease known to be a scourge of the berry: blueberry shock virus.

Blighted flower clusters due to blueberry shock virus infection. https://www.ncipmc.org/projects/pest-alerts/blueberry-shock-virus-bromoviridae-harvirus/

Click to download a PDF version of the Blueberry Shock Virus publication.

“We’re studying diverse blueberry plants to understand the genetic basis for blueberry shock virus, which can significantly impact yields for farmers,” she said. “Our hope is to use the insights from this project to develop new cultivars that are resistant, or at least more tolerant to, the disease.” Blueberry shock virus has caused annual crop losses of 34-90% in the Pacific Northwest.

Researchers combine traditional plant breeding with genomics to create their disease-resistant cultivars. The traditional technique (used in one form or another by people trying to improve agricultural crops for millennia) is to take pollen from one plant and use it to pollinate a different plant with complementary characteristics. They study the progeny of these crosses, looking for new characteristics that meet the goals of the breeding programs. Traditional blueberry breeding can take more than 20 years from the time an initial cross is made to when a consumer might eat from a resulting cultivar.

“We try to improve the accuracy and speed of the plant breeding process,” Luby explained. “We are now able to obtain a lot more genetic information about the plants and we can use that information to potentially predict whether an offspring of a given cross might have the characteristics we are looking for before we plant it out in the field. This is important because it can increase the speed of the plant breeding process.”

“Our goals are to develop blueberries that require fewer chemical inputs to fight disease, which can be better for both the environment and for growers’ bottom lines,” Luby said.

 The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.

Crop Planning for Sustainable Vegetable Production


Twin Oaks Garden Colored Spots Plan for crop planning

At the in-person Pasa Sustainable Agriculture Conference, I gave two presentations. I also sent a recorded workshop for their virtual conference in January. That one was Feeding the Soil. I’ve just scoured through all 8 pages on my website that check the category “Slideshows”. I found Feeding the Soil twice.

My Alliums Year Round presentation is new this year and I posted the handout after my presentation at VABF. Pasa had shorter workshops, so I pruned the slideshow, but left the handout with the “bonus material”.

My other presentation at Pasa was Crop Planning for Sustainable Vegetable Production. That is one of the very first topics I tackled when I started out as a speaker, so the three versions on this website span the past ten years. 2014, 2016, 2019. Here is the 90 minute 2023 version and ts handout:

Crop Planning 2023 90 min presentation
Crop Planning 6 pg Handout 2023

 

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?

My Cuban Agroecology Tour Summarized

January 2020 OGS Cuba Trip Group

In January 2020 I was part of a group tour of Cuban farming organized by the Organic Growers School. In 9 days we visited 9 farms, had several speakers address aspects of life (and particularly farming and environmental issues) in Cuba, had a couple of walking tours, ate many delicious farm-to-table type dinners and still had time for a salsa lesson.

When I got home I planned to follow up with a public slideshow, but instead we got the Covid pandemic. I made a series of blogposts, which you can revisit:

My Cuba farming trip. 1/20/20

A Cuban Bean Seed Bank 3/17/20

Finca Marta Agroecological Farm, Cuba 4/28/20

Cuban AgroEcology Tour: La Palma Farm, Pinar del Rio Province 8/4/20

Cuban Agriculture: Finca L’Armonia (Permaculture Farm), Viñales 9/29/20

Cuban Agroecology Tour: Finca Agroecológica El Paraiso, Viñales 10/27/20

Cuba Agroecology: Patio Pelegrin organoponico in Pinar del Rio, Cuba 12/15/20

Cuban Agriculture, Las Terrazas Ecovillage, Artemisa 1/13/21

Cuban Agriculture, French coffee plantation Cafetal Buenavista 3/03/21

Cuban Agroecology: FANJ and La Felicidad Permaculture Garden 3/31/21

Cuban Agriculture, Dinner at the Garden of Miracles restaurant with Rafael Betancourt 4/28/21

The roof garden at the Garden of Miracles Restaurant.
Pam Dawling

And now at last I have completed my slideshow, after begging photos from a couple of my tour group, to cover the gaps in my collection.

You can view the slideshow here:

Cuba Agroecology Tour 2020

Your Chance to go to Cuba

And now I hope I’ve inspired you to consider going on one of the Organic Growers School Cuba Trips in early 2023

https://organicgrowersschool.org/events/travel-cuba/ This link includes a YouTube of testimonials

January 3-12, 2023

April 4-13, 2023

“This 9-day tour of Cuba’s sustainable farms, community gardens, and historical centers provides a rare opportunity to learn about the Cuban food system and learn about alternatives to corporatized agriculture. Participants will have the chance to:

  • Learn from farmers and food activists about Cuba’s transition to agroecological farming practices and its national policies that prioritize sustainable farming and hunger remediation.

  • Connect with farmers, consumers, activists, NGOs, policymakers, and experts working to transform the global food system.

  • Acquire the knowledge and strategies to create just, sustainable, local, and healthy food systems in your own communities.”

Check out the linked presentation for a summary of the January 2022 tour and for a sneak peek of the types of activities involved in the tour. OGS successfully operated a tour group in January 2022. No-one got Covid. OGS brought the first educational trip from the United States to Cuba since the beginning of COVID

Finca Paraiso, Vinales, Cuba. Lettuce bed. Photo Pam Dawling

Please see the OGS website for more information.

On the website you can get your most likely questions answered: legal, financial and health requirements, sample itinerary, reasons to visit Cuba, reasons to go with OGS, reasons to value agroecology, and a one-hour Info session video. The trip includes bus transportation within Cuba, a minimum of 2 meals each day, 9 nights in casas particulares accommodation, a very good ag-knowledgeable tour guide and tour manager, and entry fees to various sight-seeing exhibitions.

Farmer Fernando Funes Monzote showing us the vegetable beds, terraced on contour, at Finca Marta, Artemisa, Cuba
Photo by Pam Dawling

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

<iframe src=”https://www.slideshare.net/slideshow/embed_code/key/D7gjiECOI6i83w?hostedIn=slideshare&page=upload” width=”476″ height=”400″ frameborder=”0″ marginwidth=”0″ marginheight=”0″ scrolling=”no”></iframe>

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

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

Planning and Growing Winter Hoophouse Vegetables

 

Hoophouse winter greens.
Photo Kathleen Slattery

If you have a hoophouse, you may now be planning or planting crops for fall, winter and spring. If you don’t have a hoophouse, this is a good time of year to consider getting one. See Twenty Benefits of Having a Hoophouse at the end of that post. There are grants available from NRCS, including reparation levels of funding from traditionally underserved groups of people. There are now companies that will construct your hoophouse for you, if you don’t want to do it yourself, or can’t. If you do want to build your own, there are detailed instructions in my book The Year-Round Hoophouse. You can buy the book here on my Books page direct from me, or from my publisher New Society, or you can buy it wherever books are sold.

The Year-Round Hoophouse cover

I have many posts about winter hoophouse vegetables, so rather than try to write something completely new on the topic, I am going to give you a guide to find your way around the information already here.

General Hoophouse Info

Winter hoophouse growing

Hoophouse video interview

Year-Round Hoophouse Vegetables slide show

Hoophouse Cool Season Crops slideshow

Hoophouse Many Crops slideshow

Hoophouse Bright Lights chard in winter.
Photo Wren Vile

Hoophouse Crop Planning

Planning winter hoophouse crops

Hoophouse Crop Rotations

Preparing for spring, sowing seeds, planning

Hoophouse Greens Clearance, Warm Weather Crops Established

Hoophouse Crops Winter 2022-2023

Hoophouse Bed Prep

Hoophouse fall bed prep

Fall hoophouse bed prep

Hoophouse bed broadforked to loosen up slumped soil. I’m happy to say our soil structure has improved in the 18 years since this photo was taken!
Photo Pam Dawling

Choosing Hoophouse Winter Crops

(see also my post categories on the right side of the computer screen, for special posts on Asian Greens, Cooking greens, lettuce and root crops)

How to decide which vegetable crops to grow

Winter-Kill Temperatures of Cold-Hardy Vegetables 2021

Spinach variety trial conclusions

September in the hoophouse: sowing spinach

Young spinach seedlings.
Photo Pam Dawling

Sow onions in a hoophouse

Frilly Mustards in our Winter Hoophouse

Three cheers for Ruby Streaks!

Yukina Savoy in the Hoophouse

Cooking Greens in December

Cooking Greens in February

Cooking Greens in March

Yukina Savoy in the early morning mist.
Photo Wren Vile

Asian Greens in October: Yukina Savoy, Tatsoi

Asian Greens for December: Pak Choy

Asian Greens for January: Chinese Cabbage

 

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

Lettuce All Year in a Changing Climate

Year Round Lettuce

Lettuce growing in October

Lettuce in December

Lettuce varieties for January

Early Lettuce Production

Cold-tolerant lettuce and the rest

Tango lettuce from our September 24 sowing on January 10.
Photo Pam Dawling

Planting in the Hoophouse (Both Transplanting and Direct Sowing)

The decision between transplanting and direct sowing

Sowing hoophouse winter crops

Seedling winter crops

Starting Seedlings

Bare Root Transplants

September sown White Russian kale (transplanted in October).
Photo Wren Vile

Keeping Every Hoophouse Bed Fully Planted and Productive

Using all the space in the winter hoophouse

Fast Growing Vegetables

Sequential Planting slideshow

Young Tokyo bekana transplant in our hoophouse .
Photo Pam Dawling

Caring for Hoophouse Crops

What makes vegetable crops bolt and how can I stop it?

You don’t want this! Bolting lettuce outdoors in July
Photo Alexis Yamashita

What to Do If Something Goes Wrong with Your Hoophouse Crops

Back-up plans for winter hoophouse crops

Plans A-D

Emergency back-up seedlings for the hoophouse.
Photo Pam Dawling

Harvesting in the Winter Hoophouse

Winter hoophouse harvests

Mid-winter hoophouse harvests

This winter week in the hoophouse

Young greens in the hoophouse

Winter Harvests

Making baby salad mix

Beautiful baby lettuce mix in our hoophouse.
Photo Wren Vile

Three Methods of Growing Sweet Potato Slips

Growing sweet potato slips in an old fridge used as a warm insulated cabinet.
Photo Kathryn Simmons

Sweet potatoes are grown from “slips,” (pieces of stem with a few leaves), grown from a mother root, not from seeds or replanted roots. We used to buy bare-root slips for transplanting, because we didn’t know how to grow our own, and had heard it wasn’t easy. We have been growing our own for many years now, and prefer the flexibility and reliability it gives us. We did make several mistakes initially, so I can warn you about what not to do. We have a system that we really like, and I have learned a few other methods that I will also tell you about, including one I helped out with the past two years, growing them in a hoophouse.

Disadvantages of buying sweet potato slips

  1. You need to specify a shipping date months ahead, then hope for good weather and no shipping delays.
  2. You might have late frosts, spring droughts, or El Niño wet springs, and climate change is only adding to the uncertainty, but slips that arrive in the mail need immediate attention.
  3. You have to get them all in the ground promptly, and do your best to keep them alive (because they arrive wilting).
  4. Some amount of drooping (transplant shock) is normal.
Cut sweet potato slips in water.
Photo Kathryn Simmons

Advantages of growing your own sweet potato slips

  1. You can delay planting if the weather is all wrong (frost, drenching rain, heatwave)
  2. You can grow them big and plant 3-5 nodes underground, giving more chance of survival if there is a late frost, or an early drought.
  3. You can plant them in stages rather than all on one day.
  4. You can grow extra and keep them on hand to replace casualties.
  5. The sturdy plants get off to a strong start – the transplants don’t wilt – a big advantage where the warm season is on the short side for a 90- to 120-day plant.
  6. You have more self-reliance and less money going out.

 How not to grow sweet potato slips

I made several mistakes learning to grow slips. You don’t have to repeat my mistakes! My first error – following directions written for much further south (in pre-internet days), was to try growing slips in mid-January in central Virginia. Dismal fight against nature! Likewise, I was puzzled by talk of using cold frames. Ours were freezing cold at that time of year.

Next, I set up a soil warming cable in a cinder-block-enclosed bed on the concrete floor of our greenhouse. This is how I discovered most soil warming cables have thermostats that switch off the heat at 70°F (21°C). I just couldn’t get the soil warm enough.

Sweet potatoes on a plate.
Photo Brittany Lewis

Three Successful Methods of Growing Sweet Potato Slips

  1. Twin Oaks slips-in-flats method
  2. Boutard single node cutting method
  3. Hoophouse or caterpillar tunnel bedding method (Twin Oaks)
Flat of home-grown sweet potato slips.
Credit Kathryn Simmons
  1. Twin Oaks Slips-in-Flats Method

I’ve written about this before, so I’ll just give you a link to open another page.

Starting Sweet Potato Slips discusses pros and cons of growing your own slips, and describes our “slips in flats” method, which I learned from Hiu Newcomb of Potomac Vegetable Farms. Here is our Worksheet we use to stay on track with that task.

Sweet Potato Plan 2022

 

Single-node sweet potato slip at 16 days.
Photo Anthony Boutard
  1. The Boutard single node cutting method

Anthony Boutard and Caroline Boutard Hunt wrote an article about single node sweet potato propagation (which they learned from John Hart of Cornell) in Growing for Market in March 2015. They farm in Oregon and New York respectively.

Both the slips-in-flats method and this one start at the same time, planting roots in damp compost in a warm greenhouse. I corresponded with Anthony Boutard about our respective methods. He pointed out that the slips-in-flats method needs a lot of warm space to grow the slips, at a time when warm space is at a premium. Our method does take us from early March to mid-May.

The single node cutting method uses only 10-20% of the number of mother roots compared to the slips-in-flats method. It uses tiny plants in plug flats, saving on greenhouse space, and only needs 18 days between cutting the slips and planting in the field. The smaller plants can experience less transplanting shock than larger plants. On the other hand, I do not think they have the resilience that multi-node plants have, for example if a late frost strikes.

When these plants grow in the field, their root production is from the single node. This can lead to fewer, but very large tubers, an advantage or a disadvantage, depending on your goals. Better in climates with a short warm season than in hot places, although digging after a shorter growing period would be possible in warm climates.

This method can be used to grow more plants from purchased cut slips, which is very helpful if you are growing a rare heirloom with limited propagation material available. Plant the bought slips in the greenhouse and grow them on until you can make cuttings.

Like the slips-in-flats method, this one buys time if the weather turns bad and you need to back pedal on your planting out date.

Single-node sweet potato slip showing roots three days after striking the cutting.
Photo Anthony Boutard.

To prepare single node cuttings, cut a slip from the mother tuber and cut off about ¼” (6mm)  above a leaf node (the swollen point where the leaf emerges). In the leaf axil is a bud which will grow a shoot, and just below the bud is a ring of cells that can grow roots. You can trim back the leaf stem, or leave the leaf on. Make the second, lower, cut just above the next node down. You can make several cuttings from one regular slip.

50-cell plug flats work well to grow the cuttings. Push the lower end of the shoot cutting at an angle into the cell, creating an even V with the leaf stem. If a cutting is too tall to fit your cell plugs, you can cut more off the lower end. The new shoot will then grow upwards easily from the bud in the leaf axil.

Keep the trays warm and moist, and plant out after only 18 days, into well-prepared damp soil, with drip tape in place. Delaying planting for 10 days or so is not a problem.

This post includes a discussion of the Single Node Method, in an article in Growing for Market magazine by Andrew Schwerin from NW Arkansas. In warm climates, only use this method if you want really big tubers!

Hoophouse beds of sweet potato mother roots in early May
Photo Pam Dawling
  1. The Hoophouse Bedding Method

I learned this method from my friend and colleague River Oneida, who grew slips for Southern Exposure Seed Exchange. He planted up 4 beds 45’ (14 m) long with three rows/bed in a single-layer hoophouse and grew an average of 4000 slips/week, for a 6 week sales season (24,000 slips), with a peak and bell-curve ends of the season. Caterpillar tunnels could also work.

Store your saved roots at room temperature. From March 1 onward: start the sweet potatoes sprouting indoors in stages, as heated space permits, at 85°F (29°C), and high humidity. Remove any rotting potatoes. When each potato grows ¼” (6 mm) sprouts, take it out of the heated space and replace with new ones. Put the ¼” (6 mm) sprouted ones at room temperature to slow them down for batching with later ones.

In March:  Cover the bed area in the hoophouse with a single layer of clear plastic, and kill any weeds that pop up. Four weeks before shipping starts (on April 1 in central Virginia), prepare the beds in the hoophouse. Dig out a flat-bottomed bed 1” (2.5 cm) deep, and set the sprouted sweet potatoes an inch (2.5 cm) apart in rows. One or two sprouts are enough. If possible, don’t bed unsprouted roots

Spread some compost, not lots. Replace the soil you dug out, on top of the sweet potatoes. Add soil from the aisles, putting 1”-3” (2.5-7.5 cm) of soil on top of the potatoes. Not more. Set out drip tape and irrigate regularly.

After bedding, stab holes in the plastic every 4” (10 cm) for respiration. Check regularly, opening the plastic on warm days once slips are visible. In mid-April or whenever you see slips emerging, remove the plastic in the daytime, but put it back for frosty nights Add more soil later to cover exposed tubers if needed. Regulate temperature if you want a faster or slower rate of production.

Fresh sweet potato slips for sale from Southern Exposure Seed Exchange.
Photo Pam Dawling

Some slips will be ready from the 3rd or 4th week of April onwards. If too many slips are ready at any point, pull and heel them in outdoors. Remember to water.

I first wrote this up for an article for Growing for Market magazine, and have included it in my updated slideshow, at the end of this post. It’s a great method for people growing lots of slips (for instance, for sale). It could also be used for smaller amounts, by occupying a corner of a hoophouse growing other crops at the same time.

More Posts on Sweet Potatoes

I have written a lot on sweet potatoes at all stages from propagating our own slips, growing them all summer, and harvesting. My posts include:

Sweet Potato Propagation and Yields

Transplanting Sweet Potatoes (biodegradable plastic; deterring deer)

Planting Sweet Potatoes, includes stages of growth, and links to many other sweet potato posts, including most listed here.

Growing High Yielding Sweet Potatoes

 Sweet potato harvests over the years (2020) summarizes my writing about harvesting, including Harvesting Sweet Potatoes (2016); Sweet Potato Harvest (2015) and again (2015) and earlier (2014) and in 2013, 2012

What Makes Sweet Potatoes Sprout (during storage)

I also have a blog post for Mother Earth News Organic Gardening blog, about growing sweet potatoes. And I have several articles in Growing for Market, which you can access online if you have a Full Subscription.

More information

For more info, see

ATTRA Sweet Potato: Organic production

North Carolina State University, Pests of Sweetpotato
North Carolina State University Diseases of Sweetpotatoes.

I have an updated Sweet Potato Slideshow  

Growing Sweet Potatoes from Start to Finish 2021

More on Insectary Flowers; Vegetable Crop Resources, Especially Weeds

 

Borage flowers attract many beneficial insects. Spot the honeybee! Photo Raddysh Acorn

More on Insectary Flowers (to attract beneficial insects)

A reader responded to my post Growing flowers to attract aphid predators in early spring

“Isn’t too cold for the predators to be around, Pam? unless they hibernated in the greenhouse. but even so, it’s still cold in there at night. We have some aphids too in the tatsoi and some of the lettuce, so thank you for all the tips, and the life cycle. I had not quite realized that the cycle was so short. I grow borage in the hoophouse but in the ground – the plants get large and gorgeous with clouds of blue flowers in March and April – much bigger and healthier than anything I try to grow outside. The honeybees absolutely love it and they attract are a lot of other insects too.”

Yes, it has been still too cold for predatory insects to be around, until this week, when ladybugs greet us around every corner. Our idea with the flowering plants was that by starting the plants in the fall, we’d have actual flowers earlier than if we started in “spring”, and that perhaps the extra stresses would even cause the plants to flower earlier. Apart from the borage, none of the others have flowered yet (Feb 23). We likely need to fine tune our sowing dates. We sowed at the very beginning of September and the very end of October. That two-month gap probably has better sowing dates! We noticed that some of our plants were not very cold-hardy. Some died and some had to be pruned of dead bits. Since then, we started more flowers in our greenhouse on February 1. Another thing we’re noticing since early February is that the plants in pots dry out very fast. It’s probably better to get the flowers in the ground in the hoophouse and greenhouse as soon as they are big enough, as suggested by the results of my reader quoted above, with borage.We had thought that having them in pots would enable us to move them into trouble spots.

Vegetable Crop Resources, Especially Weeds

Spiny amaranth – a weed to exterminate by careful pulling.
Photo Pam Dawling

A newly released handbook from Sustainable Agriculture Research and Education (SARE), Manage Weeds On Your Farm: A Guide to Ecological Strategies by Charles L. Mohler, John R. Teasdale and Antonio DiTommaso, is set to help us all. I haven’t read it yet (although I am looking forward to that!), so this is not a review, But these are three big names in weed science, and SARE is well-known for providing solid information on sustainable farming.

Silver Queen sweet corn with a wilting pulled amaranth plant in the center
Photo Kathryn Simmons

I had the great good fortune to attend a workshop by Chuck Mohler years ago, and got some realizations that forever changed my approach to weeds. Top of the list is that some weeds, such as pigweed (amaranth species), don’t distribute any seeds until they have grown very big. Until that point they are not threatening next year’s farming efforts. We used to get huge pigweed plants in our sweet corn, and fatalistically did nothing once we were in there harvesting, somehow believing it was “too late”. No, it’s not! They hadn’t seeded. We started to make a practice of pulling the huge pigweed every two days while harvesting corn. Often it was necessary to stand on the base of the corn plant to hold it in place, while pulling the weed. Then all we had to do was drop the pigweed between the rows. Sweet corn ripens in hot weather and the weeds soon died, rather than re-rooting. All those big leaves sucked the moisture right out of the plants. Be extra careful if you have spiny amaranth. We have twice eliminated this weed form our gardens, by diligent hand-pulling, only to have it reappear a few years later!

Galinsoga – a fast growing, fast-seeding weed of cultivated soil.
Photo Wren Vile

Conversely, galinsoga forms seeds very soon after germinating, while still small. This weed is one to strike early and repeatedly. It readily re-roots in damp soil. Our strategy when we are too late to hoe and have to hand-pull them, is to shake off as much soil as possible, then to either twist and break the stem (if there are not many), or “shingle” the weeds, laying them down with the roots of one on top of the leaves of the previously pulled plant, providing a surface of roots all exposed to the air, and none touching the soil. This works quite well. Timely hoeing is much better, of course!

Manage Weeds has chapters on How to Think About Weeds, Cultural Weed Management, Mechanical and Other Physical Weed Management Methods, Profiles of successful managers,  and then the alphabetical rogues gallery of grass weeds and broadleaf weeds.

This book and all the online information from SARE is free of charge. You can buy print copies if that suits you better. Other good resources from SARE, while you’re at their website, include several other books:

Building Soils for Better Crops

Managing Cover Crops Profitably For many of us, this is the “Cover Crops Bible”

Systems Research for Agriculture

Crop Rotation on Organic Farms 

There are also podcasts, bulletins, videos, Topic Rooms and interactive pages to explore.

Winter Vegetable Production Methods

For those who missed the Pasa Sustainable Agriculture conference, here is my slideshow Winter Vegetable Production Methods, From the Field to the Hoophouse

Winter Vegetable Production Methods, From the Field to the Hoophouse Dawling 60 mins 2022 2.11 9am

Fall and Winter Vegetable Growing, Harvest and Storage

 

China Rose Winter Radish.
Photo Seed Savers Exchange

You can find a wealth of information on my website about growing, harvesting and storing winter vegetables. There are many links here in this post (all should open in a new tab, so you won’t go down a rabbit hole), and you can also use the search box in the upper right to enter whatever vegetable you are wondering about, and “grow” “harvest” or “store”, Remember I also have several annual series of posts, on Asian greens, root vegetables, workhorse crops, alliums, cooking greens, and lettuce. Just don’t look for “Storage lettuce” until April 1st.

I’ve also included some good blogs that I sometimes consult.

  1. Fall and Winter Vegetable Growing

Season extension into cold weather

Prepare your garden for colder weather: plant winter crops if there is still time, use rowcover on hoops to protect crops from wind and cold weather, plant up every little bit of space in your greenhouse or hoophouse.

See my posts

Spinach over-wintered in our cold frame
Photo wren Vile

And here’s a post by Shannon Cowan, the blog editor at Eartheasy.com:

Winter Gardening: Best Crops to Extend Your Harvest

Shannon suggests using a variety of strategies. “Plant some vegetables that will mature quickly, others that will hold well in your garden beds, and still others that will overwinter and begin growing again when the days lengthen.”

This is also my approach. See my posts

Fall-grown senposai.
Photo Pam Dawling

Good late season vegetables: salad greens, Swiss chard, beans, peas (in climates milder than 7), carrots, radishes, senposai, spinach, pak choy, cabbage and winter lettuces.

Good cold hardy vegetables: Plant in late summer and fall to harvest throughout the winter. These late-sown crops reach full maturity before seriously cold weather, and hold so you can harvest them when the rest of your crops have been eaten. They don’t usually grow much during the winter, but they do stay fresh. Grow enough to supply your needs without depending on any further growth. This category includes Asian greens, beets, broccoli, Brussels sprouts, cabbage, carrots, collards, kale, leeks, scallions, spinach, turnips and other root vegetables,

Good crop protection so you can grow some crops through the winter. If your winter temperatures routinely drop below 25 F (- 4 C), crops need protection, from simple rowcover to hoophouses or greenhouses. This improves the temperatures, but it’s hard to address the reduced amount of daylight or sunlight. The increased warmth, plus the protection from winds, can be enough for some, such as spinach, kale and lettuce, to make some growth whenever their temperature is greater than 40F (5C).

Using a sturdy digging fork to harvest leeks in December.
Photo Pam Dawling

Good slow growing crops to harvest outdoors in late winter or early spring. In this category are crops that go into the winter less than fully grown. After the winter solstice, when the days begin to lengthen, crops start growing again, making them usually ready for harvest very early, much earlier than any crops planted after the solstice. They don’t usually need winter protection and include beets, some types of broccoli, cabbage, carrots, collards, kale, onions, garlic, garlic scallions, spinach, kale and collards.

See my post Winter radishes, planting garlic.

Good crops to grow in hoophouses include arugula, beets, chard, Chinese cabbage, collards, kale, lettuce, Maruba Santoh, mizuna, mustards, pak choy, parsley, radishes, spinach, tatsoi, Tokyo bekana, turnips and Yukina Savoy

Hoophouse Bright Lights chard in winter.
Photo Wren Vile

See my posts

  1. Fall and Winter Vegetable Harvest

See my posts

Harvested Purple Top Milan and White Egg turnips.
Photo Pam Dawling

Here are some links to a couple of good sources for more harvest information:

Piedmont Master Gardeners Garden Shed Newsletter

Guidelines for Harvesting Vegetables by Pat Chadwick

A list of seven basic principles of harvesting, followed by a crop-by-crop list of almost 50 individual crops and a resource list of 18 publications (focused on the mid-Atlantic and Southeast)

Roxbury Farm Harvest Manual (Roxbury Agriculture Institute at Philia Farm)

October Tips from Harvest to Table, by Steve Albert covers all climate zones and comes complete with a USDA Hardiness Zone Map

Links to other posts by Steve Albert

  1. Fall and Winter Vegetable Storage

I already have posts on root cellar potato storage, onion storage (alliums for August), Garlic storage, Storage vegetables slide show, Root Crops April, Feb, Jan, Dec, Nov.

See my posts

Sweet potatoes in storage. An ideal crop for winter meals, as they store at room temperature for a long time, maybe seven or eight months. Photo Pam Dawling