Our hoophouse has been up since 2003, and in these 20 years has had several replacements of the big roof plastic. We’ve replaced the end wall plastic less often, as it isn’t inflated and a few holes don’t matter. It’s true that old dirty plastic doesn’t let as much light in, but we are firmly on the side of not replacing end wall plastic and roof plastic in the same year.
I wrote Replacing Hoophouse Plastic in September 2017. Six years later, here we are again. This year we needed to replace all the baseboards, too, as the 2″ thick cedar had rotted, and for a few months a section of wigglewire channel holding the plastic had completely detached from the baseboard. We considered whether to buy cedar, metal baseboards or plastic lumber baseboards. I wrote about the pros and cons of each in May (2023). We ultimately decided to go with the “Hat Channel” metal baseboards from Tunnel Vision Hoops. We wanted something long-lasting at a fair price. We have a small concern about the metal baseboards lacking thermal insulation, compared to lumber, or even plastic lumber, but on balance it seemed like our best bet. No regrets, and Tunnel Vision Hoops were really helpful.
We removed the old plastic in the middle of September, after we had planted one bed with early crops. We continued bed prep and planting in the fresh air until October 11, when we got the new plastic on.
It took us a long time to remove all the rotted baseboards. We started out undoing as many bolts as possible, but then a helpful colleague showed up with a power reciprocal saw and cut through all the remaining ones. We also had to remove all the crumbling old duct tape we had bandaged the metal connectors and bolt heads with. Just in time, one of the crew suggested we buy Gorilla tape instead. We were pretty unhappy about all the silver dandruff of micro-plastics from the duct tape landing on our soil. Gorilla tape is thicker, stickier, less flexible, and most importantly lasts a lot longer. We saw we had used a little of it last time, in 2017, and it was still good. We had also used some pewter-grey exterior duct tape in 2017, and it was still good too. No idea where we bought that.
We had a hope to be ready for the new plastic on October 6, but we had to deal with our slightly nervous inexperience installing metal baseboards. By this point in the year, we had to watch the forecast not only for days without rain, but also one with calm winds (below 5 mph) and we had hit a breezy spell. Our average first frost is October 15 or so, and the nights started to get chilly. Juggling all these factors, we did really well and got the plastic on during the one day that week without winds above 5 mph. We also kept up with all the October bed prep and planting, which is intense. Yay, team!
I won’t repeat what I’ve said before (click the links). If you are launching on a similar recovering, study our step-by-step instructions. If not, simply enjoy the photos.
Another new idea this year was to take a 25 x 100′ silage tarp that was handy, and spread it out along the south side of the hoophouse to unroll the new plastic on. Another is to lift the roll of new plastic by inserting hoe handles in the cardboard tube, lift, and have someone walk out the free end. Much easier than pushing the roll along the ground!
We really like to have 6-8 people, who we hand pick and invite. I have found out the hard way that being open to all volunteers leads to things going wrong. We also think 5 ropes is the minimum for this length of hoophouse. We plan to have 7 next time. We value having a spotter inside the hoophouse to push up on any jammed tennis balls, and a spotter on the south side (outside), who can see progress with the outer layer going up and call to individuals to pull more or pause, so that the plastic goes up evenly.
We had some trouble with the outer layer snagging, and speculated that it might be because our frame does not have a ridge pole, just two high purlins. The tennis ball lingered in the saggy bit of plastic too much. I also think we could practice smoother knots, to reduce the chance of snags.
We ordered 48′ x 100′ Tufflite IV and Tufflite IR and PolyPatch tape for our 30′ x 96′ gothic-shaped tunnel from Nolts Greenhouse Supplies in PA. We use the wigglewire and aluminum channels (also called Polylock), which are reusable over and over.
Tall stepladder and 2 pairs of shorter stepladders
For a 30′ x 96′ tunnel, at least 8 rolls of high quality Gorilla tape. Stinginess doesn’t pay.
Tools for each person: pliers, soup spoon, flat-bladed screwdriver, scissors.
Utility knives to trim the plastic when it’s on right. Bolt cutters (for the wigglewire)
Tennis balls and ropes to pull the edge of the plastic over the top. At least 5 sets for a 96′ house. Use ropes long enough to go over to the other side – say 5′ longer than the width of your plastic.
A sock and a plastic water bottle (to attach to the throwing end of the rope)
Polypatch tape and scissors. Accidents will happen. Try to be gracious and forgiving!
We’ve already prepared our first bed in the hoophouse and sowed our first few crops (spinach, radishes, scallions, tatsoi, Bulls Blood beets and cress). We spread the bed prep out over 5 days and the sowings over 2 days. I’ve written lots about our fall hoophouse planting, so I’ll give you links, mention a few updates and stick to photos otherwise.
Hoophouse Winter Schedule Tweaks and Improvements (pack more crops in, get higher yields, reduce or spread the workload). One change we made was to sow some early catch crops in areas that weren’t needed for all-winter crops until later. We mostly used tatsoi and Tokyo bekana, both fast–growing leafy greens. We intended to grow some early beets too, but the seed didn’t germinate. A new crop last winter was cress, Creasy Greens Upland Cress and Belle Isle Upland Cress from Southern Exposure. They take 50 days to maturity (in spring). We had two good intentions we did not manage to follow through on. One was to let some of the cress flower, to feed beneficial insects. And I think we got too impatient. The other was to notice which one of the two kinds we prefer and just grow that one. We didn’t manage to keep good enough records on that, so this winter we are obliged to repeat the experiment, with more good intentions!
Fall hoophouse bed prep and shadecloth removal (packing away the giant piece of shadecloth until May, spreading compost, broadforking and raking the beds, direct sowing the first bed, sowing seeds in an outdoor nursery bed to transplant into the hoophouse a few weeks later). This post includes a step-by-step guide to hoophouse fall bed prep. Our soil is improving each year, becoming easier to broadfork and rake. That counters the aging process of our human bodies! One change we made last year was to measure and pin down the drip tapes 12” (30 cm) apart, and use the drip tape as a guide to making furrows (drills). This is easier than using the row marker rake, as we used to do.
Sowing hoophouse winter crops(more details on bed prep tools and techniques, including the row marker rake if you want to use that, and links to posts about winter lettuce varieties we used in 2017/2018.)
Planning and Growing Winter Hoophouse Vegetables(hoophouse crop map, many links to other posts including a video and three slideshows, crop rotations, choosing winter hoophouse crops, posts about specific crops (with all the details), back up plans in case something goes wrong, and harvesting.)
Preparing your hoophouse for fall and winter(includes one of my slideshows, and a more detailed discussion of lettuce types and sowing dates, information about salt build-up and our wash-down strategy in a 3-slide mini slide show, when we close and open the doors and windows, and a Be-Prepared Winter Kit list)
Winter hoophouse growing (includes a round-up of earlier posts, and a discussion about the value of crop rotation in the hoophouse, and a list of 20 benefits of having a hoophouse.)
Spinach variety trial conclusions This year we are growing Acadia. Johnny’s do not recommend this variety for late fall or winter sowing, but it did very well in our hoophouse, sown in September, October, November and January.
Spinach is a much-loved crop for us. We sow outdoors and in the hoophouse in early September for harvesting from fall through to spring (April). We sow outdoors in late September for a crop to overwinter as small plants and be harvested in the spring. We also sow in our coldframes in mid-September. These are more sheltered than the beds outdoors, and the spinach makes faster growth. We sow more spinach in the hoophouse in October and November. We sow in the hoophouse in January to transplant outdoors and in the hoophouse in February for spring harvests. We are able to keep harvesting spinach (leaves, not whole plants) from October 15 to May 25, all the way through the winter. Central Virginia is too hot to have spinach during the summer (we switch to chard).
Unsurprisingly, I have written about spinach several times.
Choose varieties that do well in climates similar to yours, in the conditions you have when you plant and harvest. We used to grow Tyee for all plantings, and were very happy with it. But it has been pulled from the market because it had disease problems in the Pacific North West, where spinach seed is grown. We have tried and not continued Chevelle, Corvair, Renegade (grows fast, but has thin leaves and bolts early in spring), Avon (Downy Mildew in winter).
Also see the 2015 Greenbank Farm Spinach Variety Trial. The farm is in Washington State. They evaluated 10 varieties of savoyed and semi-‐savoyed spinach with two side-‐by-‐side replication in spring. Abundant Bloomsdale, Bloomsdale Long Standing, Butterflay, Giant Winter, Dolce Vita, Longstanding Bloomsdale, Lyra, Solstizio, Tyee, Winter Bloomsdale. The overall star of their trial was Solstizio from Nash’s Organic Produce.
Paul and Sandy Arnold in Argyle, New York, made a great slide show reviewing Spinach Varieties in High Tunnels. I think it’s no longer available online, but I did learn that in 2019, their top Winter Spinach Varieties were Escalade, Carmel, Whale, Space, Reflect; top Summer Spinach Varieties: Banjo, Seaside, Woodpecker.
In 2011-2012, High Mowing Seeds in northern Vermont did a spinach variety trial with 24 varieties. Three farmers in Iowa conducted a 2021 trial of spinach varieties and seedling methods. They compared yield, bolting and yellowing among three spinach seeding methods: seeder (1x rate), seeder (2x rate), hand-seed (2x rate); and between two varieties (Kolibri, Kookaburra). Two of them found no statistically significant difference of seeding method on yield; one found no difference in yields between the two varieties, but using a seeder at a double rate produced significantly higher yields than the other two methods.
When to sow fall spinach
Spinach does not germinate in hot soil! Use a soil thermometer and wait for the soil to cool to 68F (20C), or see the next section about sprouting spinach seed in a cold place. If you have no soil thermometer, see my post chickweed, hen-bit and dead-nettle, and use the info that was originally written with lettuce in mind, for spinach! There are photos there of these three plants at seedling stage. These are winter annual weeds here, that don’t grow in summer. Once we see their seedlings emerging in late August (a cool summer year like 2023) or September (most years) we know the soil has cooled enough to sow lettuce and spinach directly in the ground.
A trick for getting good timely germination of spinach seed is to put it (in sturdy resealable plastic bags or jars) in the freezer for about two weeks. Take the seeds out of the freezer the day before you want to sow (or start sprouting them), but – important – do not open the bag or jar. Leave it to warm to ambient temperature before opening. Otherwise the warm humid air will rush in and coat the cold seeds with condensation, reducing the shelf life of whatever seed you have left over for another time.
September 6 is our first sowing (sprouted seeds) in the hoophouse for winter harvest 10/30-2/15, or later if it doesn’t bolt.
We sow outdoors on September 7 (sprouted seeds) for growing under rowcover and harvesting in fall and winter.
September 18-20 we sow in our coldframes and outdoors for harvest in early spring, until late May.
October 24 we make our second hoophouse sowing, to feed us November 25 to May 7.
On November 9,we make a third hoophouse sowing, intending to use these plants to fill gaps in our hoophouse as other winter crops come to an end.
January 16 we make more sowings in the hoophouse, some to continue to fill gaps there along the edges of the beds where they won’t fight with the tomatoes and so on, which we transplant starting March 15. Most of the spinach sown on this date is for transplanting outdoors on February 21.
January 29 we sow in flats in the greenhouse if we see we haven’t got enough bare-root transplants in the hoophouse.
February 10 If we don’t have enough transplants, then on this date we sow outdoors with rowcover, for spring harvests until May 25 if we’re lucky. We have backup plans on backup plans for this!
In the hoophouse we continue transplanting spinach to fill gaps until March 31.
Sprouting Spinach Seed
This very easy work-around involves soaking the spinach seed in water overnight, draining it, and putting the jar on its side in the fridge for a week. If you remember, give the jar a quarter-turn each day to even out the moisture. You are not growing bean sprouts! A little neglect will not cause harm. The ideal is to have short sprouts, not long ones, as those break off more easily. Sow the seed in the furrows gently, by hand. If the sprouts have got tangled, add some water to float them apart, drain them, spread them on a tray, or a layer of rowcover, to dry a bit, then mix with some inert dry soil-friendly material like uncooked corn grits or bran, which will help them not stick together.
Sowing Spinach in Speedling Flats and Floating them in Water
Another option is to start the spinach in flats and transplant it all. That’s a lot of work, but we found we could save on the daily attention time and the transplant time by using 120-cell Styrofoam Speedling flats. Sow one or two seeds per cell, then float the flats all day in water. Depending on your scale, this could be a baby bath or a stock tank. Remove the flats each evening and let them drain all night (while it is hopefully cooler). With just twice a day visits and no hand-watering, this is a big time saver, and we have got good germination rates.
When it comes time to transplant, the tool of choice is a butter knife. Use the knife to wiggle a wedge-shaped hole in the bed. Slide the knife down the sloping side of the cell, and, holding the base of the plant with one hand, use the knife hand to lift and flick the plug out. If all goes well, the plug will be then be resting on the now-horizontal knife, and you can slide it into the pre-made hole and firm it in.
Spinach makes growth whenever the air temperature is 40F (4.4C) or more. So any winter protection you can provide, in the way of cozy microclimates, rowcover, coldframes, or a hoophouse, will increase your yield. Spinach is more cold-hardy than many people realize. It dies at 0°F (-18°C) unprotected outdoors. Savoyed varieties tend to be a little hardier than smooth-leaved types. Large-leaved savoyed spinach outdoors with no protection can get seriously damaged at 10F (-12C). Small-leaved plants are OK down to 5F (-15C).
Our outdoor spinach gets hoops and thick rowcover (Typar, 1.25 oz/sq yd spunbonded polypropylene, with 75% light transmission, and about 6 F (3.3 C) degrees of frost protection). It can last for 6 years or more. When we got 0F (-18C) the spinach leaves that touched the rowcover got big patches of beige/tan dead cells, but the plants recovered to produce more leaves.
Ben Hartman (author of The Lean Farm) wrote Testing the Limits of Cold Tolerance in Growing for Market magazine in February 2014. He reported that his young hoophouse spinach in Goshen, Indiana, with mid-weight rowcover survived -16F (XXX). Ben points out that spinach less than 1″ (2.5 cm) tall is very cold-tolerant. Bigger plants need more protection if it’s going to get that cold.
You can read more about growing spinach in my Cooking Greens monthly series.
Growing bare root spinach transplants
We grow our spring spinach transplants (as well as kale and collards) in the soil in our hoophouse, sowing them in late January. See bare root transplants . You can find more links and info in that post. Growing bare root transplants saves a lot of work and a lot of greenhouse space.
Our goal is sustainable long-season harvesting. This is important for winter crops, as making a new sowing during cold dark days will not produce much food until spring comes around. It’s like the goose that lays the golden eggs – keep the leafy “golden eggs” coming
We harvest spinach by cutting individual leaves and leaving the plant to continue to produce more.
Our rule is “Leave 8 for later” – cut off large outer leaves close to the base of the plant, being sure to keep at least 8 of the inner leaves growing on each plant. Over-harvesting leads to decline.
When we finally pull up the bolting plants in spring, I’m always amazed to see how many leaf-scars there are on each plant, showing just how much we’ve harvested.
For those relatively new to this blog but living in a similar climate zone, I want to point you to The Complete Twin Oaks Garden Task List Month-by-Month. It includes a link for each month’s task list. I notice from the site stats that some of you are finding your way there, but now there are so many years’ worth of posts it’s perhaps harder to find. Happy browsing!
Each year we grow two 96′ (29 m) beds of early tomatoes in our hoophouse. We plant them mid-March, start harvesting at the end of May, and pull them up at the end of July or beginning of August. By that point the plants have reached as high as we can go and the outdoor plants have started producing large amounts, so we don’t need to ask more of the hoophouse plants. Each year we grow varieties that we’ve had years of success with, plus a few new ones.
Last year I wrote My favorite tomato varieties, about the four we trialed then: Pink Boar, Geronimo, Cherry Bomb and Estiva. We decided to grow Pink Boar and Cherry Bomb again, but somehow we didn’t! Pink Boar developed more splits and more disease in the last few weeks as the season reached its end. Cherry Bomb was out of stock when we placed our seed orders, so we tried another red cherry, Sakura.
Sakura is a 55 day indeterminate red cherry. It did well, resisted disease. But when I checked why it didn’t seem very productive, I discovered that a confused planter had planted only one Sakura and an extra Black Cherry instead! Next year, maybe we’ll try Cherry Bomb again, or try really planting two Sakura!
We stopped growing Stupice, a 62 day indeterminate red, in favor of
more Mountain Magic, 66 day indeterminate reds. A plan is just a plan. Somehow, a bunch of Black Cherry (64-75 day indeterminate purple) got substituted for some Mountain Magic and some Garden Peach at planting time, due to more worker confusion. We love Black Cherry, but they take longer to pick than larger tomatoes. Some might argue that Mountain Magic at 2 oz (56 g) are not that much bigger then Black Cherry at ½-1 oz (14-28 g), but as you see, they are at least twice as heavy. The disease-resistance of Mountain Magic, Glacier and Garden Peach was medium this year.
None of us missed the Stupice, with their green/yellow shoulder problem. As I noted last year, the lack of red lycopene in the shoulders might be due to too much heat. We did try not pruning the Glacier (56 day determinate red) at all this year, and we got less of a green shoulder problem with those, so that’s worth remembering. We’d like to keep that one, as it is so fast at ripening. Sungold is still faster, though catalogs claim Glacier should be one day ahead.
This year, I wanted to try several large red round fast-maturing tomatoes, and a couple of different colors. To be chosen for our hoophouse crops, tomatoes have to mature in 80 days or less. Our main red is Tropic(80 day indeterminate red). It’s good at setting in heat and has a good flavor, but this year had a lot of disease. This summer has been peculiarly mild, up until mid-August, so not a good test of heat-setting tomatoes.
We tried two plants each of Skyway (78 day 8-12 oz (112-168 g) indeterminate red) and, for the second year, Estiva (70 day indeterminate red). Both looked impressive: big shiny unblemished fruit. But no flavor worth reporting. Estiva had good disease-resistance, and split resistance, but was slower to fruit than the 70 day claim.
We planned to try Premio (60 day 4 oz (56 g) indeterminate red), but didn’t get any seed. Maybe next year?
We did try Mountain Fresh Plus (75 day determinate large 8-10 oz (112-224 g) red, short plants) for a second time. “The most widely-grown market tomato in the East and Midwest” Johnny’s Selected Seeds. We are a fan of many of Randy Gardner’s “Mountain” series of tomatoes, but not this one. It wasn’t very productive, and the flavor wasn’t exciting.
Jubilee (80 day indeterminate orange) is our main orange slicer, and that did very well, with medium disease resistance this year. The fruit looked a little different this year. Possibly we were still sowing seed we bought during the pandemic, which came labelled “Probably Jubilee”. It’s also called Golden Jubilee.
We also trialed Mountain Spirit(77 day indeterminate large yellow/red) and Purple Boy (80 day indeterminate large purple, Park Seeds). Neither of these wowed us much. Production was low and flavor was only so-so. We had hoped Purple Boy would be a good substitute for Cherokee Purple, which splits and yields poorly in our hoophouse. Mountain Spirit had a mushy texture.
I’m concluding (provisionally!) that large fruited tomatoes are not such a good idea for us. We do better with more productive, more modest sized tomatoes.
We came up with an idea to reduce the chance of misplanting in future. We didn’t want to write labels for every single potted tomato, so we have been labeling just the rows of 3 or 6 in a standard 1020 flat, which holds 18 pots. This means we often have more than one variety in a flat. We have small numbers of purple, brown and green pots, so we can use those for particular varieties. Mostly we have the standard black pots. Our new idea is colored dot stickers, which are often to be found in our office is oddly large numbers. I wonder if anyone else ever uses them?
Our mid-Atlantic weather mostly comes from one of three directions,
mainly from the Gulf of Mexico, (wet, maybe windy)
the Bermuda High Pressure area in summer, (hot and dry)
recurrent waves of cold air from Canada in winter (from a disrupted polar vortex).
Due to the erratic movement of thunderstorms, some parts of our area may experience long periods of drought. September–November is the dry season but also the hurricane season.
Find a weather station that is a good match for your area, and learn how to adapt it
We use Wunderground.com for Louisa Northside, but subtract 5F° from their forecast night lows, and mentally downgrade the chance of rain by 10%, as rain often passes us by as it scoots along the river valley north of us. I use the ten-day forecast to get the general idea, the hourly one when planning tasks, the Roanoke animated radar on the daily page to see what’s on the way and when it’s likely to arrive, and the alerts, watches and warnings. The forecast for the month is under the Calendar tab, although the further out the forecast is, the less reliable it will be. In hurricane season I check the Severe Weather tab with the Hurricane and Tropical Cyclones information.
Make yourself a Frost Alert Card of conditions that are likely to lead to an early or late frost, so you can quickly take avoiding actions without dithering.
Learn about recent average weather at your location.
I recommend Weather Sparkfor browsing on a rainy day, or a too-hot afternoon. “The weather year round anywhere on earth”
I rechecked our area on Weather Spark recently and realized how much has changed since I started quoted information from our Extension Service twenty or more years ago.
The climate in Louisa County, Virginia, is changing on average in the past ten years to drier weather with milder winters, hotter summer nights.
Twin Oaks is in USDA Winter Hardiness Zone 7a: the average annual minimum winter temperature is 0°F–5°F (–18°C to –15°C).
The average rainfall for a year is 37” (100 cm), fairly evenly distributed throughout the year, at 2.2”–3.6” (5.6-9.1 cm) per month. October is the driest, May the wettest.
The average daily maximum temperatures are 49°F (9.4°C) in December and January, 89°F (31.7°C) in July. The average night low temperatures are 29°F (–1.7°C) in January, 69°F (20.5°C) in July.
The season from last frost to first frost, is around 211 days. The average date of the last spring frost is April 24 (later than May 7 only happens one year in ten); the average date of the first fall frost is Oct 14 (earlier than Oct 1 only happens one year in ten).
Weather SparkOn Weather Spark you can study artfully-made colorful charts of temperature, precipitation, cloud coverage, humidity and tourists (!) month by month. There is a chart of average high and low temperatures over the year, and one showing the average hourly temperature over the year (we are currently in the big red blob of hot afternoons). There’s a grey and blue chart of cloud coverage, and a green one of the daily chance of rain (with touches of blue and purple frozen precipitation). The average monthly rainfall chart is all greys, as is the snowfall one. Our greatest chance of snow is February with an average of 4.2” for the month.
You can compare your nearest city to another you might dream of moving to.
There are charts of hours of daylight and twilight, sunrise and sunset, the solar elevation and azimuth (for those planning greenhouses); moon rise, set and phases for a choice of years; and – oh – humidity! Color-coded from a comfortable green, humid yellow, tan mugginess, pink oppressive and orange misery (over 75%).
There’s a chart of average wind speed over the year; wind direction, which shows my wrong belief that most of the wind here comes from the west (true in July, December and January only). There’s also (keep scrolling) a chart about the growing season, by which they mean the longest continuous period on non-freezing temperatures, although the chart provides a very visual bigger picture of periods in various temperature bands.
There’s a Growing Degree Days chart! We’re on average at 2000 F GDD at this point in July. Next is a chart of solar energy (average daily incident shortwave solar energy), with kWh peaking in June at 6.9 per day.
There’s more details, but I’m moving on.
Check extreme weather
For when you need to know, check outReal Time Lightning Maps.org. On the map, enlarge the area you are concerned about., and watch for the activity sparking, or click for sound. There’s an explanation of how the data is gathered and what the various color dots mean.
Windy.comhas a colored map with streaming arrows, and other settings for rain and thunder, clouds, temperature and more. For those at seas, you can check the waves and swell.
AirNow.gov has a quick-to-read dial of air quality, fire and smoke maps, ozone, fine particulates, lots of information about air quality
Not exactly weather, but if you experience an earthquake, go to Did You Feel It? And register your experience. It helps USGS build a clearer picture of earthquake events in your area. You can see maps of recent earthquakes globally or a world map to give understanding of tectonic plates.
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.
“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
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.
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.
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!
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.”
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.
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.
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. firstname.lastname@example.org 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.
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.
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. . .
Steel C-section joists
RepurposedMaterialsis 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.
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.
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.
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.
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.
The 23rd annualVirginia 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!
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 workshopSunday January 8, 10.30 am – noon, Asian Greens in the Winter Hoophouse
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.
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
Cold damage update
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
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”
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.
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.
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.
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!
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.
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.
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.