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

Lettuce All Year in a Changing Climate

We like to eat lettuce year round, and have put time and energy into finding the varieties and planting dates that work best here in Central Virginia, as well as how to get the best results in each season. Recently I revised our lettuce schedules, partly to take account of hotter weather arriving earlier in the year, and also to even out the harvest dates.

I have frequently written blogposts about growing lettuce. And I have a whole year of Lettuce for the Month posts. See here for the overview, or click on the month you want to know more about. These posts are mainly about our favorite varieties for each time of year.

I have a slideshow Lettuce year round – It’s at the end of this post.

Back in 2006, I wrote Lettuce: Organic Production in Virginia for VABF. We’re now in Winter Hardiness Zone 7a. Back then we were 6b. Read this publication for details you are hazy on, but see our updated Lettuce Varieties List and Lettuce Log in this post.

Fast-growing Red Salad Bowl lettuce.
Photo Bridget Aleshire

Choose appropriate lettuce varieties for each time of year.

Sow several varieties each time to spread the harvest season and the risks of poor germination. I like to use something fast, something slow; at least one red; a romaine, a bibb and a couple of leaf types.

Consider multileaf lettuces too, Salanova and Eazyleaf brands. They are bred for uniformly small leaves, with more texture, loft and flavor than baby mixes and faster harvesting. Transplanted 6″–8″ (15-20 cm) apart they produce 40% more than baby leaf mixes. The full-size plant can be harvested as a head, providing a collection of bite-sized leaves. Or just one side (or the outer leaves) of the plant can be cut and the plant will regrow for future harvests. Growing multileaf heads takes 55 days, compared to 30 days for baby lettuce

Red Hawk Farm hoophouse densely planted with multileaf lettuces.
Photo Pam Dawling

Our recent changes to our Lettuce Varieties List include switching over from “Early Spring” varieties to “Spring” varieties at the end of February rather than the end of March. This means we only make 3 sowings of the early spring varieties, and we need to stop buying much seed of those varieties! Next year I might even abolish that category and those early varieties to simplify life.

The spring varieties we now sow from February 28 to April 22. We used to sow these until May 15. We’re still making 5 sowings of those, but the dates have moved earlier.

On April 23 we switch over to our Summer varieties, which we make 20 sowings of, until August 14. (Buy lots of seed of those varieties!) We then switch to nine sowings of Fall varieties, until September 7.

Lettuce growing in our greenhouse in November.
Photo Wren Vile

From September 8 to the end of September we use our cold hardy varieties. These 9 sowings include those for the greenhouse and hoophouse, which will feed us all winter.

Click to access Lettuce-Varieties-pdf.pdf

You’ll need a large screen, a magnifying glass or the ability to expand the image.

We like to grow a balance of leaf lettuce and head lettuces, and, in winter, baby lettuce mix too. We harvest the baby lettuce mix when 3″–4″ (7.5–10 cm) tall, cutting 1” (2.5 cm) above the soil. We harvest leaves from the big lettuces the rest of the time. Baby lettuce mix is very pretty, but I actually prefer the juiciness and crunch of big lettuce.

Beautiful baby lettuce mix in our hoophouse.
photo Wren Vile

Keys to year round lettuce

· Store seed in a cool, dry, dark, mouse proof place.
· Grow your lettuce quickly, for high quality and flavor, using good soil preparation and high organic matter.
· Learn the skills of lettuce germination in all weathers. Minimum soil temperature for germination is 35°F (1.6°C). Optimum temperature range for germination is 68°F–80°F (20°C–27°C).1/4″–1/2″ (6–10 mm) deep is ideal. Good light.
Watch the temperature – Germination takes 15 days at 41°F (5°C), 7 days at 50°F (10°C), 3 days at 68°F (20°C) and only 2 days at 77°F (25°C). Germination will not occur reliably at temperatures hotter than 86°F (30°C).
Keep watching the temperature – Optimum growing temperatures are 60°F–65°F (15°C–18°C), Some growth occurs whenever the temperature tops 40°F (4.5°C).
· Choose good locations! We grow lettuce outside from transplants from February to December (harvesting from late April); in a solar-heated greenhouse from September to March (harvesting leaves from November) and in a solar heated hoophouse from October to April (harvesting leaves from November, and whole heads in April). We also sow baby lettuce mix in the hoophouse from October to February, for harvest multiple times from December to April.
· Use shade cloth on hoops in hot weather
· Use rowcover in cold weather, or plant in cold frames, greenhouses or hoophouses.

Lettuce under shade cloth.
Photo by Nina Gentle

Grow a consistent lettuce supply using succession crop planting

To have a continuous supply, it is important to plant frequently, at intervals adapted for the time of year. The gap between one sowing and the next gets smaller as the year progresses; the gap between one transplanting and the next does likewise. The number of days to reach transplant size dips to 21 days in the summer, then lengthens as the weather cools and the days get shorter.

We made a Lettuce Succession Crops graph using our records for sowing date and harvest start date. From this we determined the sowing dates to provide us with a fresh harvest (120 heads of lettuce, or equivalent) every single week. We made a Lettuce Log with our planned sowing, transplanting and harvest dates. This is explained in my slideshow Lettuce year round.

Lettuce Succession Crops Graph

Click to access Lettuce-Succession-Crops.pdf

Rouge d’Hiver hardy romaine lettuce.
Photo Bridget Aleshire

Recently I fine-tuned this in light of more recent records. In some cases we had been led astray by a spreadsheet date calculator that was based on 30 day months in a 360 day year! Not reality! We also had data showing that transplants were not always ready on the dates we had thought, probably due to a mistake in an earlier year when we were unable to transplant on time, and repeated the delayed date the next year. Most of the tweaking was in early and late spring, and then in August.

Click to access Lettuce-Log.pdf

Tips for growing good quality lettuce

I recommend transplanting lettuce (other than baby lettuce mix) at 4-6 true leaves (3-6 weeks of age). It is worth learning good transplanting skills, so that plants thrive, even if transplanted in mid-summer.

Water enough, with an efficient irrigation system. Water new transplants daily for the first 3 days, then every 4-7 days after that. Lettuce needs a relatively large amount of water throughout its growth. Deeper weekly waterings equivalent to 1” (25 mm) of rain are better than frequent superficial irrigation – roots will grow deeper, giving the plant greater drought-resistance.

To make best use of space and time, plant lettuces 10-12” (25-30 cm) apart, in a hexagonal pattern. If you plant too close, you are restricting the size of the lettuce. If you plant with more space than needed, you will waste time dealing with more weeds!

Flats of lettuce transplants in our cold frame in April.
Photo Pam Dawling

Transplanting gets a head start on weed control, which is important from planting to a couple of weeks before harvest. Don’t waste time hoeing lettuce you will be harvesting next week. I generally find that if I hoe once, a couple of weeks after transplanting, that is all the weed control I need at the fast-growing time of year. We like the stirrup, or scuffle, hoes, which are safer in the hands of novices than sharp edged hoes, because the blade is in a closed loop.

Some growers use black plastic mulch, but I hate filling the world with single use plastic, so we don’t do that. Some others use landscape fabric with melted holes at the right spacing. I used this for strawberries and liked it. I’m not sure I’d find it worthwhile for fast-growing lettuce. No-till growers can transplant into mulch, first making what we call “nests” at the appropriate measured spacing. It’s tempting to skip the measuring, but if you drift from a 12” (30 cm) spacing to a 15” (38 cm) spacing, you will end up with fewer lettuces!

For those who like to direct sow lettuce, you could prepare the bed, let it rest for a week (watering it), then flame or lightly hoe the surface before sowing to remove a flush of weeds.

Lettuce seedlings for transplanting later. Photo Pam Dawling

Bolting and/or bitterness are more likely with under-watering, long days, mature plants, poor soil, crowding, high temperatures, and vernalization—once the stems are thicker than 1/4″ (6 mm), if plants suffer 2 weeks of temperatures below 50°F (10°C), followed by a rapid warm-up.

Bolting lettuce in July
Photo Alexis Yamashita

Deal promptly with pests and diseases. Aphids, cutworms, slugs, rabbits, groundhogs and deer all like lettuce as much as we do. If you find your lettuces melting down with fungal diseases, you can, of course, commit to better crop rotation. You can also consider solarizing beds for next year’s lettuce. You need a minimum of 6 hot weeks in which to cook the soil-borne disease spores by covering the prepared beds tightly with clear plastic. Old hoophouse plastic is ideal – construction plastic does not have the UV inhibitors that prevent the plastic shattering into shards.

More resources

Cornell has a 2016 Organic Production and IPM Guide for Lettuce 67 pages of everything you are likely to need, for growing in New York type climates, at least.

Ray Tyler at Rose Creek farm has a Lettuce Masterclass, a step-by-step blueprint to plan, grow, and sell lettuce year-round!

This slideshow is from 2019, before I made the changes I mention above.

Lettuce Year Round 60 mins

Early Lettuce Production

Young Salad Bowl lettuce
Photo Wren Vile

Early Lettuce Production

Growing early season lettuces involves choosing suitable types and varieties (cold-tolerant and fast-growing), having successful production methods, and a good schedule. Harvesting early in the year might mean fast production in January and February, or it might mean starting in the fall and overwintering the plants. See my post series Lettuce of the Month, for ideas on varieties and techniques throughout the year.

Our Climate Zone in central Virginia is 7a, which means our annual minimum temperature averages 0°F to 5°F (-18 to -15°C). The average date of the last spring frost is April 30 (later than 5/14 one year in 10). We grow lettuce outside from transplants from February to December, in a solar greenhouse from October to early March, and in a solar-heated double-layer hoophouse from October to April.

Swordleaf, Red Salad Bowl and Bronze Arrow lettuces.
Photo Bridget Aleshire

Lettuce Types

There are several different general types of lettuces. In terms of growing speed, the baby lettuce mixes and the leaf lettuces produce harvests soonest after sowing. Loose-leaf lettuces are very useful because you can harvest individual leaves while you’re waiting for the heads to reach full size.

Leaf types are ready for harvest 45-60 days from direct seeding, 30-45 days from transplanting. Bibbs mature in 60-75 days, most head lettuce need up to 80 days from seeding, or 60-70 days from transplanting in spring. Romaines are slower-growing (70 days or more). Batavian lettuces (also called French Crisp) are tasty, thick-leafed varieties that have excellent heat and cold tolerance. Icebergs mature in 75-100 days.

Baby lettuce can be cut 21 days from seeding, (except from November to mid-February, when it may take 2 or 3 times as long).

Bolt-resistance generally goes from Leaf types (first to bolt), through Romaines, Butterheads, Bibbs, to Crispheads.

I like to sow four lettuce varieties each time (for the attractive harvests, and to reduce the risks if one variety bolts or suffers disease): at least one red and one romaine. We have 5 lettuce seasons, with different varieties:

Early Spring (Jan – Mar), 6 sowings
Spring (April – May 15), 5 sowings
Summer (May 15 – Aug 15), 17 sowings
Fall (Aug 15 – Sept 7), 9 sowings
Winter indoors, Sept 8 – 27, 9 sowings

Lettuce Varieties

Bronze Arrow lettuce ultra-closeup. Photo Bridget Aleshire

It’s important to grow the right lettuce variety for the conditions. For earliest harvests, consider a different, faster, variety than you have usually grown. Some of the early spring lettuce varieties are often useless here if sown after mid-March, or even mid-February, because they bolt prematurely as the Virginia spring flips from cold to hot (and back again, grrr!). Varieties we only sow until 2/15 include Bronze Arrowhead (46 day leaf lettuce); Buckley, Ezrilla and Hampton (55d multi-leaf types); Merlot (60d), Midnight Ruffles (48d) and Oscarde (45d) (leaf lettuces). Antares (48d) Panisse (48d) and Revolution (38d) leaf lettuces we can sow until 3/15.

Nancy bibb lettuce
Photo Bridget Aleshire

Others that we like in early spring go on to be useful later in spring too. In this category are Buttercrunch (a small 50d bibb); Nancy (58d) and Sylvesta (52d) (two big green bibbs); Pirat (55d red bibb), Green Forest (56d), Kalura (57d) (two green romaines); and New Red Fire (55d), our reliable Salad Bowl (45d) and Red Salad Bowl (46d), Starfighter (52d), and Swordleaf (53d) (leaf lettuces)

New Red Fire lettuce.
Photo by Bridget Aleshire

The baby lettuce mixes we like are Fedco’s 2981 LO Lettuce Mix OG (contains at least six different lettuces) or Johnny’s Allstar Gourmet Lettuce Mix #2310 (including green and red oakleaf, green and red romaine, lollo rossa, and red leaf lettuces). One gram sows 25 ft, one ounce will sow about 600 feet.

For those with challenging growing conditions, both companies offer other specialized selected mixes.

Cold-tolerance of lettuce

Red Tinged Winter and Tango lettuce in our hoophouse in December.
Photo Pam Dawling

Lettuce is more cold tolerant than many people realize. If plants are sufficiently hardened (prepared by growing in gradually lower temperatures), they can withstand freezing. At 22°F (-6°C), large leaves of some lettuce will die. Medium-sized plants with 4-10 leaves (Marvel of Four Seasons, Olga, Rouge d’Hiver, Tango, Winter Density may survive unprotected down to 15°F (-9.5°C). Half-grown lettuces are more cold-hardy than full-sized plants.

Lettuce Crop Requirements

Lettuce seed remains dormant unless triggered by adequate levels of light and temperature. It needs light to germinate, so don’t sow too deep: ¼-3/8″ (6-9 mm) is enough. Some sources recommend not covering the seed at all, but this can make it hard to keep the seed damp. The light dormancy is more pronounced in fresh seed, which has higher levels of the hormone that controls germination.

Soil temperature is important. I have a table of optimum soil temperatures for germination in The Year-Round Hoophouse The optimum temperature range for lettuce germination is 68-80°F (20-27°C). It takes 7 days to germinate with a soil temperature of 50°F (10°C) or 15 days at 41°F (5°C), and only 4 days at 59°F (15°C). Even a few hours at temperatures higher than the optimum can induce dormancy.

Lettuce transplants prefer a well-draining soil high in organic matter, and with a pH of 6.0-7.0, not lower. Optimum growing temperatures are 60-65°F (15-18°C), with a minimum of 40°F (4.5°C) for any growth to occur. Lack of water will lead to bolting, and/or bitterness. Keep them growing quickly for good flavor.

Lettuce in January

A flat of newly emerged lettuce seedlings
Photo Kathryn Simmons

We plan to start harvesting heads of lettuce outdoors from April 15. Before then we will harvesting lettuce in our greenhouse and hoophouse.

In mid-January we sow four lettuce varieties, to become our first outdoor transplants. I recommend sowing several varieties each time to spread your risks, if one kind bolts or suffers disease. I choose varieties that cover the range of colors and shapes. I select hardy types that are fast-maturing. Buttercrunch green bibb lettuce is one of my favorites for early spring. One of the Salad Bowl lettuces, red or green, is also usually in my first sowing. The Salad Bowls are so reliable and productive! New Red Fire has become another reliable lettuce stand-by for us. It was suggested to me by neighboring Virginia farmer, Gary Scott of Twin Springs Farm. It is more of a leaf lettuce, and doesn’t exactly head up, although it can be cut as admittedly lightweight heads. It works fine as a leaf lettuce, harvested by the cut-and-come-again method. We grow New Red Fire year round, it’s that adaptable and easy-going. We haven’t found many good full-size red romaines. Bronze Arrow has worked well for us and we were harvesting it in early May.

We grow all our outdoor lettuce as transplants. In spring we sow in 3″ (7.5cm) deep open wood seed flats, 12″ x 24″ (30 x 60cm). We make four little furrows by pressing a 12″ (30 cm) plastic strip (aka a ruler!) into the seed compost. We sow the seed, label it, cover it lightly, water, and put the seeded flats in our germinator cabinet. The first flat of the year takes about 9 days to germinate.

Spotting cabbage seedlings from a seed flat into a transplant flat.
Photo Wren Vile

Once the seedlings are big enough to handle, we spot them out into 4″ (10 cm) deep flats (also 12″ x 24″/30 x 60cm). We have a plywood dibble board with pegs evenly spaced about 2.5″ (6 cm) apart. We aim to harden off the lettuce for two weeks in the cold frame before transplanting into the garden beds with thick rowcover on hoops to protect the lettuce from the still-cold outdoors. To be ready for harvest 4/15, these seeds have to become full size lettuces in 88 chilly days.

Seeds can instead be sown in cell packs or plug flats, putting three seeds in each cell, and later reducing to one seedling with scissors. Cells or pots with diameters from 1-2½” (2.5-6cm) can be used. The 96-cell size (1×1½”/2.5x4cm) works well, although the 200-cell size (1×1”/2.5×2.5cm) is possible if you can be sure to get the transplants out before they get root-bound. If warm germination space is limited in early spring, sow seed in a small flat, then “spot” the tiny seedlings into bigger flats, 606 (2×2¼”/2.5x6cm) cell packs, or 32-pack square pots to grow on in cooler conditions before planting out. Soil blocks are also possible, but take more time.

We make a second sowing on January 31. The intervals between sowings at the beginning of the year are long, because later sowings will catch up to some extent with earlier ones. Most crops grow faster in warmer weather.

Lettuce in February

We sow lettuce twice in February – 14 days apart. We get ready to transplant our first outdoor lettuce, to feed us mid-late April. Our first sowing of baby lettuce mix in the hoophouse comes to the bitter end, and the second sowing is awaited. We continue to harvest leaves from the large lettuce we transplanted in the hoophouse in October.

Lettuce in March

Lettuce with sclerotinia drop.
Photo Pam Dawling

We sow flats of lettuce every 10 days in March. March 9 is our goal for a transplanting date outdoors for our first 120 lettuce (about one week’s worth for 100 people).

Here is a link to a helpful publication from eXtension: Disease Management in Organic Lettuce Production. Horribly useful photos!

Baby Lettuce Mix

Baby lettuce mix can be ready in as little as 21 days from mid-spring to mid-fall, longer in early spring. 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.

Lettuce for March and all year

Bronze Arrow lettuce is a beautiful and tasty early spring variety.
Photo Bridget Aleshire

We’re continuing to have enough lettuce. We have pulled the first baby lettuce mix in our hoophouse, and have started pulling some heads in there. Of course, we want to harvest the hoophouse head lettuce before it gets too bitter, but we also don’t want to get too far ahead with the harvesting and run out! Our second baby lettuce mix is now ready for cutting, and the third sowing is not far behind.

March 9 is our goal for a transplanting date outdoors for our first 120 heads of lettuce (about one week’s worth for 100 people). We sow four varieties each time, some green, some red, different shapes and textures, different numbers of days to maturity. This way we hope to have a constant supply, and hedge our bets if something goes wrong with one variety.

In our first sowing we have Parris Island green romaine, Buttercrunch green bibb, and Hyper Red Rumpled Wave, a very red leaf lettuce, as well as Bronze Arrow, shown above. Our second sowing includes Cosmo, another green romaine, Star Fighter, which I wrote about last June, Oscarde, a red wavy leaf lettuce and one of our work-horses, Red Salad Bowl. Our third sowing has Panisse, a green wavy-leafed variety, Revolution, a red leaf lettuce, Swordleaf, which I wrote about last spring, and green Salad Bowl.

Ezrilla Tango-type one-cut multileaf type lettuce
Photo High Mowing Seeds

Buckley red oakleaf one-cut multi-leaf lettuce.
Photo High Mowing Seeds

Our fourth sowing includes New Red Fire and three Eazyleaf lettuces ( Ezrilla, Hampton and Buckley) sold by High Mowing Seeds. We are simply trying these out this spring, to find out if we want to grow them next winter. In our climate these are unlikely to stand for long in the spring, and much more likely to grow well in our hoophouse in winter.

Hampton one-cut multi-leaf lettuce.
Photo High Mowing Seeds

These are varieties that produce lots of small leaves (no big leaves) enabling growers to get an instant salad by cutting a whole head. We are more likely to harvest them multiple times, taking some leaves each time. It’s exciting to see more lettuces of this type on the market. I wrote previously about Osborne’s Multileaf lettuces and Johnny’s Salanova varieties.

Here’s a link to our Lettuce Log, our schedule of lettuce planting and harvesting dates, that provides a succession of outdoor lettuce from April to November:

http://file:///X:/GARDEN/Planning/Lettuce%20Log%202017%20in%20Htm.htm

Gardening is not all about lettuce! We have sowed two beds of carrots outside and also a bed of turnips (Purple Top White and White Egg), with a row of radishes to pull before the turnips need the space. And we are still “recovering” from transplanting 3600 spinach plants. They are all doing well, despite my mix-up about which varieties were intended to be planted in which bed. We are comparing three varieties this spring: Tyee, Avon and Reflect.

Purple Top White Turnips.
Photo Small Farm Central

White Egg Turnips.
Photo Southern Exposure Seed Exchange

Lettuce in February, Growing for Market, open seed flats

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

We still have plenty of lettuce to eat, although our first sowing of baby lettuce mix in the hoophouse has come to its bitter end, and the second sowing isn’t quite ready (I think we sowed it a bit later than intended). We are still harvesting leaves from the large lettuce we transplanted in October. Soon we’ll have the second and third baby lettuce mix sowings to bring a welcome change. We are about ready to transplant our first outdoor lettuce, to feed us mid-late April.

Here is a month-by-month planting and harvesting narrative for our hoophouse lettuce in Zone 7, from September to April:

September: Sow cold-hardy varieties in the second and third weeks (outdoors or in your greenhouse) to transplant into the hoophouse at 4 weeks old .

October: 4 weeks after sowing, transplant those lettuces at 8” spacing to harvest leaves from mid-November to early March, rather than heads. In late October, sow the first baby lettuce mix, for up to 8 cuts from early December to late February, and sow a small patch of “filler lettuces” to replace casualties in the main plantings up until the end of December.

November: 11/9 sow more filler lettuce, to be planted out in the hoophouse during January. Transplant the first “filler lettuce” to replace casualties. Harvest leaves from the transplanted lettuce.

December: Use the “filler lettuce #1” to replace casualties or fill other hoophouse space, for lettuce leaves in January and February, or heads in February. At the end of December, make a second sowing of baby lettuce mix, to harvest from late February to the end of March. Harvest leaves from the transplanted lettuce, and cut the first baby lettuce mix.

January: Use the “filler lettuce #2” to fill gaps in the lettuce beds up until January 25. After that is too late here for hoophouse lettuce planting, and we use spinach to fill all the gaps, regardless of the surrounding crop. Harvest leaves from the transplanted lettuce, and cut the first baby lettuce mix whenever it reaches the right size.

February: 2/1 sow the third baby lettuce mix, to provide up to three cuts, from mid-March to late April. In mid-February, consider a fourth sowing of baby lettuce mix, if outdoor conditions look likely to delay outdoor harvests. Harvest leaves from the transplanted lettuce, and cut the second baby lettuce mix when it sizes up. Harvest the first baby lettuce mix, clearing it at the end of February before it gets bitter.

March: Harvest leaves from the transplanted lettuce, and cut the second baby lettuce mix whenever it reaches size. Cut the third baby lettuce mix when it sizes up.

April: In the first half of the month, harvest the last of the transplanted lettuce as heads . Continue to cut the third baby lettuce mix until it gets bitter. Cut the fourth baby lettuce mix when it sizes up. Outdoor lettuce heads are usually ready for harvest mid-April. Plan to have enough hoophouse harvests until the outdoor harvests can take over.

Lettuce transplants in soil blocks, on our custom-made cart. We don’t use soil blocks for lettuce any more (too time-consuming!) but I love this photo. Photo Pam Dawling

The February issue of Growing for Market is out, including my article How to decide which crops to grow which I previewed some of here last August. I also included some of the material in my slideshow Diversify Your Vegetable Crops. Click the link to see the slideshow. This past winter we used this kind of process to reduce the amount of garden work for 2017. I’m retiring from garden management and the new managers want to stay sane and not be exhausted all the time. We have fewer workers this year (the past few years actually), so we needed to slim down the garden and not go crazy trying to do everything we’ve done in the past. I’ll still be working in the hoophouse, the greenhouse, and doing some outdoor work, as well as being available to answer questions and provide some training when asked.

Back to Growing for Market. There’s a great article for new small-scale growers, from Katherine Cresswell in northern Idaho, Year One Decision Making, about starting a farm with only one implement. Careful planning lead Katherine and her partner Spencer to focus on fall, winter and spring vegetables, as no-one else around them provided these, and they had experience of winter growing from working on other farms. Clearly a high tunnel (hoophouse) needed to be in the plan. It was essential that they hit the ground running and have saleable produce within six months. The expense budget was very tight. They bought a BCS 739 walk-behind tractor (which they both had experience of) and a rotary plow. A very down-to-earth article to encourage any new grower with limited means.

There are reviews of three new books by GfM writers: Compact Farms by Josh Volk, Floret Farm’s Cut Flower Garden and The Greenhouse and Hoophouse Growers Handbook by Andrew Mefferd, the editor of GfM. Brett Grohsgal has written a valuable article about his 15 years experience with on-farm breeding of winter-hardy vegetables, both in the field and under protection of hoophouses. Informative and inspiring. Erin Benzakein has written about rudbeckias, the unsung heroes of summer bouquets, and Gretel Adams has written on new flower varieties to try in 2017.

I have a new post on the Mother Earth News Organic Gardening blog, Using Open Flats (Seed Trays) to Grow Sturdy Seedlings Easily – How to make reusable wood flats (seed trays) for seedlings, and use them to grow sturdy vegetable starts to transplant into your garden. This is a way to avoid contributing to the problem of agricultural plastic trash and be self-reliant in gardening equipment. You can also grow stronger plants by giving them a larger compost volume than plug flats or cell packs provide.

Open flat of broccoli seedlings.
Photo Wren Vile

I heard that my MEN blogpost Green Potato Myths and 10 Steps to Safe Potato Eating was very popular in January, coming sixth in their table of most-viewed posts on all topics. This has been out there in the blog-iverse for almost 18 months, so clearly there is a lot of concern about eating healthy food and not wasting what we’ve grown.

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

The false spring has been barreling along. Last week I reported that we’ve seen a flowering crocus (2/17). Since then, we’ve seen daffodils and dandelions flowering, heard spring peppers and already the maple is flowering (2/25). These are all markers on our phenology list. The maple flowers on average 3/12, with a range (before this year) of 2/28 in 2012 to 4/2 in 2014. A 9-year record broken!

Lettuce growing in October

Outredgeous lettuce at an adolescent stage. Photo — Cold-hardy Outredgeous lettuce at an adolescent stage.
Photo **Southern Exposure Seed Exchange**

We’re just about to get our first real frost, and our lettuce planting has moved indoors, while our lettuce harvesting is straddling outdoors and indoors. As I reported in September, we had cutworms eating our outdoor lettuce seedlings. We sowed (and resowed on 9/16) some outdoor baby lettuce mix to play catch-up and help feed us salads until the hoophouse lettuce are ready. Yesterday, day 38 since sowing, we cut our first lettuce mix. We could have started a few days earlier. We have had a warm spell, which helped them grow faster. Because we usually only grow lettuce mix in our winter hoophouse and hadn’t planned to sow the mix outdoors, we didn’t have enough “official” lettuce mix seed. I simply made a mix of seasonally appropriate leftover fall varieties that we wouldn’t need for the second hoophouse sowing on 9/24.

Lettuce mix seedlings Photo Ethan Hirsh — Lettuce mix seedlings
Photo Ethan Hirsh

For those unfamiliar with baby lettuce mix, this is a cut-and-come-again crop. We like Fedco’s 2981LO Lettuce Mix OG or Johnny’s Allstar Gourmet Lettuce Mix #2310. For those with challenging growing conditions, both companies offer other specialized selected mixes. 1 ounce of seed sows about 600 ft, and you can sow rows 4″ (10 cm) apart. Here’s how we grow baby lettuce mix: We weed and thin to 1″ as soon as we can see the seedlings well enough to do so. Once the plants are 3-4″ tall, we cut them about an inch above the soil, with large scissors or shears. I usually gather a small handful with my left hand, cut with my right. After putting the harvested leaves in a crate or bucket, I weed the just-cut area so that there won’t be weeds in the next cut. I have also read the recommendation to rake over the rows 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.

Yesterday, as well as the baby lettuce mix, we made up our salad mix with spinach which we had sowed in the hoophouse 9/7, and brassica salad mix sown in there 10/2 (which was already plenty big enough to harvest after only 20 days. The brassica seed mix was put together by us, and was high in mizuna, I noticed.

Greenhouse with young Lettuce transplants in early October. Photo Wren Vile — Greenhouse with young lettuce transplants in early October.
Photo Bridget Aleshire

Before the weekend, we were making salad mixes using spinach from our cold frames sown on 9/8. The leaves had grown very big, helped by having drip irrigation and cinder block walls as well as a slight southward slope to the soil in the cold frame, as recommended by Eliot Coleman. We added lettuce leaves from the plants in our greenhouse, which were sown in early to mid-September and transplanted in there early October. We will keep these plants alive all winter, just harvesting leaves. When we need the greenhouse space for seedlings at the end of January, we ‘ll start clearing the lettuce.

Our home made double hoop system for holding row cover in cold windy weather. Image (c) Pam Dawling — Our home made double hoop system for holding row cover in cold windy weather.
Image (c) Pam Dawling

We’ve covered our outdoor lettuce mix and our last bed of leaf lettuce (still waiting for it to get to harvestable size) with row cover on double hoops. We roll the long edges of row cover between hoops on to reject hammock spreader bars. They are about 5 ft long, and by setting the hoops about 6 ft apart we have the right amount of space to comfortably roll the edges under. Having the row cover nice and taut over the hoops not only helps it stay in place, but also holds the row cover above the leaves and makes the likelihood of bits of row cover in your lettuce unlikely.

That’s the round-up on what salad we’re harvesting in October and how. Now on to this month’s planting. I already mentioned transplanting lettuce into our greenhouse. In September’s lettuce article I listed the varieties we sow for the greenhouse and the hoophouse. This month we have been transplanting those into the hoophouse. On 10/15 we transplanted the first sowing (9/15), about 230 plants at 10″ spacing in 4 rows in a 48 ft length of bed (half the length of our hoophouse). We expect to harvest leaves from these from 11/16 all the way to 3/1. Today (10/25) we are transplanting our second sowing (9/24), a similar sized planting. We hope to harvest from these from December to mid-April. We plan to start harvesting our outdoor lettuce heads from 4/15.

We have also just sown our first lettuce mix in our hoophouse (10/24). 10 rows 4.5 inches apart, 30 ft long. That will give us a lot of lettuce! We’ll get our first cut somewhere in the 12/5-12/22 range and might even get as many as 8 cuts during the winter. It will get bitter and need to be pulled 2/26-3/15. We’ll have some later sowings to take over before that happens.

We have also just sowed some “lettuce filler” in our hoophouse. This is a small are of a few crosswise rows of the varieties we have sown to grow full-size. We’ll use the fillers to replace casualties.or if we don’t have any casualties, we ‘ll use the rows as baby cutting lettuce like our intentional baby lettuce mix.

Where we're headed: Winter hoophouse lettuce Photo Kathryn Simmons — Where we’re headed: Winter hoophouse lettuce
Photo Kathryn Simmons

Lettuce in September, Bean borers,

Freckles lettuce is a cheering sight in spring or fall. Credit Kathryn Simmons — Freckles lettuce is a cheering sight in spring or fall.
Credit Kathryn Simmons

September is a month of change, when it comes to lettuce. We sow and transplant a lot of lettuce. The September 1 sowing is number 34 in our annual series, which runs to number 46 on September 27.

When to sow to eat lettuce in September

In September we are normally eating lettuce which we sowed from late June to mid-July. That’s a tough time for growing lettuce here, and this year was tougher than usual. We got fine seedlings up, but then they were mowed down by cutworms lurking under the shadecloth. We started new sowings in flats, up off the ground on a frame. We tried sowing baby lettuce mix to feed us during the gap. Although we sowed it in a cooler spell, it didn’t come up. We just resowed on 9/16. Now we are having a deluge – of rain, not of lettuce!

Sowing lettuce in September

From September 1-21 we sow head lettuce every 2 days. This is because the rate of growth will slow down when the weather cools, and the harvest dates of those sowings will spread out. They will all feed us through to the spring, if we protect them from cold temperatures. Before we got our hoophouse, we grew lettuce outdoors through the winter under double rowcover. It did stay alive, but we couldn’t harvest very often. Rowcover will provide a temperature gain of 4–6 degrees F (2.2–3.3 degrees C), depending on the thickness. It also reduces light transmission and airflow, but the trade-off can be very worthwhile. Lettuce can survive an occasional dip to 10°F (–12°C) with good rowcover outdoors — but not 8°F (–13°C), as I’ve seen! Adolescent lettuce are more cold-hardy than full-sized plants.

Digging compost into our cold frames in preparation for fall planting. Photo Wren Vile — Digging compost into our cold frames in preparation for fall planting.
Photo Wren Vile

Sowings in the first week of September are for planting in cold frames in central Virginia. These days we have switched to growing spinach all winter in our cold frames, rather than continue these lettuce plantings. We get better value from spinach. It grows faster than the outdoor (rowcovered) spinach, but slower than our hoophouse spinach.This means that after the last sowing for transplanting outdoors, on August 29, we get a short break on lettuce sowing.

October greenhouse with transplanted lettuce. Photo Bridget Aleshire — October greenhouse with transplanted lettuce.
Photo Bridget Aleshire

We resume with number 38 on September 9. The sowings from 9/9 to 9/17 will be transplanted in our greenhouse. We also sow on 9/15 and 9/24 to transplant into our hoophouse. The sowings from 9/19-9/27 are “insurance plantings” in case something goes wrong with an earlier [planting, or we don’t get the greenhouse beds refilled with compost soon enough, and want smaller plants.

Lettuce varieties to plant in September.

From September 1-7, (the coldframe ones we used to grow), we use cold-hardy varieties Green Forest, Hyper Red Wave, Merlot, Midnight Ruffles, New Red Fire, Oscarde, Panisse, Pablo, Red Salad Bowl, Salad Bowl, Winter Marvel (a Bibb) and Winter Wonderland (Romaine). Pablo is a hold-over from the summer Batavian lettuces. (Heat-tolerant varieties also tolerate cold.) There are also specialized cold-hardy varieties that do not tolerate heat (because they have a relatively low water content). Sow these in fall and winter only.

Salad Bowl Lettuce. Photo Bridget Aleshire — Salad Bowl Lettuce.
Photo **Southern Exposure Seed Exchange**

The salad bowls do fine in the greenhouse and the hoophouse, although I remember they are not cold-hardy enough for growing outdoors here. During the winter we will be harvesting lettuce by the leaf, rather than cutting heads. Green Forest, Kalura and Winter Wonderland are romaines that do well in the winter for us. Note that we don’t grow butterhead lettuce (bibbs) after the end of August.

Once we reach September 8, we are sowing lettuce for planting in the (unheated) greenhouse. We use Green Forest, Hyper Red Wave, Kalura, Merlot, Midnight Ruffles, New Red Fire, Oscarde, Panisse, Red Salad Bowl, Red Tinged Winter, Revolution, Salad Bowl, Tango and Winter Wonderland.

For the hoophouse winter lettuce, we sow Osborne multileaf lettuce types (Multigreen 57, Multired 4, Multired 54), Green Forest, Hyper Red Wave, Merlot, Oscarde, Panisse, Red Tinged Winter, Revolution, Tango, Red Salad Bowl, Outredgeous, Salad Bowl, Winter Wonderland Romaine. For the second sowing on 9/24, we use Include all the same ones except Oscarde, which has given us trouble in the past when started that late.

Small and medium-sized plants of Marvel of Four Seasons, Rouge d’Hiver, Winter Density, and Tango can take 15F (-9.5C). I’ve seen some small unprotected lettuces survive down to 5F (-15C) – Winter Marvel, Tango, North Pole, Green Forest. Other particularly cold-hardy lettuce varieties include Brune d’Hiver, Cocarde, Esmeralda (a bibb), Lollo Rossa, North Pole (bibb), Outredgeous, Rossimo, Sunfire and Vulcan.

I’ll address winter lettuce in some future post.

Cultivating winter lettuce in the hoophouse. photo McCune Porter.

Bean Borers

I enjoy Charley Eiseman’s blog Bug Tracks, even though I’m nowhere near in his league of paying attention to insects. It’s inspiring to read his posts! This week he wrote about Gray Hairstreak caterpillars as bean borers.

Mid-winter hoophouse harvests

December 29 hoophouse crops Photo Kathleen Slattery — December 29 hoophouse crops
Photo Kathleen Slattery

Here we are in the shortest days. What are we harvesting from our hoophouse (high tunnel)? Many different crops, mostly leafy greens, but with the addition of radishes, turnips and scallions. I’ll start with those.

White Icicle radish Photo Southern Exposure Seed Exchange — White Icicle radish
Photo **Southern Exposure Seed Exchange**

We’re harvesting our third sowing of radishes, sown on 10/30. We like the vari-colored Easter Egg radishes and the long White Icicle for this time of year. Cherry Belle also works in this sowing, but not later. Like Sparkler, it gets too fibrous in winter.

Our favorite scallions are Evergreen Hardy White, which are extremely cold tolerant. They are also slow to grow. We are starting to harvest the ones we sowed 9/6. The second sowing (which followed the first radishes on 11/18) are just spindly little blades so far.

Hakurei turnips Photo Small Farm Central — Hakurei turnips
Photo **Small Farm Central**

The turnips (and their greens) which we are starting to harvest at tangerine-size, are Hakurei and Red Round, from a 10/14 sowing. We made a second sowing of turnips on 10/26, but we over-watered them and got patchy germination. We filled the gap with a late sowing of brassica salad mix. This is a mixture of random leftover brassica seeds (varieties we didn’t like, seed that is getting a bit old) which we sow and then cut with scissors about an inch above the soil once they get to about 4″ tall.

Baby lettuce mix in the hoophouse. Photo Twin Oaks COmmunity — Baby lettuce mix in the hoophouse.
Photo **Twin Oaks Community**

Just like baby lettuce mix. We are on our second cut of our 10/24 lettuce mix. We buy the mix already made, although if we get close to running out of seed, we have been known to mix in some seed of basic varieties like the Salad Bowls, that do well in the winter high tunnel. We also have lots of big lettuce plants. We take leaves off those for our salad mixes when we don’t have baby lettuce mix at the right stage for cutting.

Ruby Streaks beside green mizuna. Credit Ethan Hirsh — Ruby Streaks beside green mizuna.
Credit Ethan Hirsh

Into the salad mix we add chopped mizuna and its spicier cousins Golden Frills, Ruby Streaks and Scarlet Frills. These add loft, visual interest and flavor. For color we also add chopped Bulls Blood beet leaves and chopped small leaves of Brite Lites chard. As well as mixing the colors and shapes, I try to have at least one representative of each of three crop families: spinach, chard and beets; lettuce; brassicas such as mizuna, baby kale leaves, small leaves of Tokyo bekana, Yukina savoy, tatsoi.

Tatsoi in the hoophouse Photo Wren Vile — Tatsoi in the hoophouse
Photo Wren Vile

For cooking greens we are harvesting leaves of Russian kale (transplanted 10/22), our first chard (transplanted 10/16), spinach (sown 9/6 and 10/24), senposai (transplanted 10/24), Tokyo bekana (transplanted 10/9) and Yukina savoy (transplanted 10/24). it takes 10 gallons of greens to provide 100 people with a healthy serving each. We aim to provide the cooks each day with a choice of two or three different cooking greens.

We are also harvesting some greens as whole heads now. We are clearing our first planting of tatsoi (sown 9/7), which has been getting ready to bolt for a couple of weeks now. Likewise the Tokyo bekana, which starts to bolt at the end of December.

Hoophouse Yukina savoy at the end of November. Photo Ethan Hirsh — Hoophouse Yukina savoy at the end of November.
Photo Ethan Hirsh

We are also cutting big heads of Chinese cabbage and Pak Choy. As we harvest these, we fill the gaps at the end of the day with replacement plants. My current favorite is senposai, as it is very quick to grow and can be eaten at any stage. (And of course, it’s very tasty, otherwise I wouldn’t even mention it!) We reckon 12/31 is the last worthwhile date for us to do this gap filling with Asian greens. After that we use spinach or lettuce transplants up till 1/25, then only spinach (up till the end of February). We’ve found that planting after those dates doesn’t produce harvest, just wasted time!

The Yukina savoy doesn’t really start bolting until the last week of January normally, but with the freakish warm weather we’ve had this December, we might get early bolting. I don’t know if this crop bolts mostly in response to day length or to temperature. I guess we’ll find out.

We’ve ordered our seeds, we’re planning our next hoophouse crops and our schedule for sowing seedlings in the greenhouse. And this is the slow season!

Bulls Blood beets add intense color to salad mixes. Photo Wren Vile — Bulls Blood beets add intense color to salad mixes.
Photo Bridget Aleshire

What’s still standing after two nights below 0F?

Recently I reported on which crops were still alive after two nights at 14F (-10C) and What’s still alive after two nights at 4F? We’ve now had the Polar Vortex, which brought us two nights at 4F, on 1/6 and 1/7. Then it got even colder.We got the Big Round 0F 1/22-1/23, then a few nights at 5F or 6F, and then the big insult: -4F on the night of 1/29-30.

What’s still standing?

The Tyee spinach under thick rowcover has sustained big damage, showing as patches of beige dead cells. It will recover. Meanwhile we can eat from the more-protected spinach in the coldframes and the hoophouse.

The Vates kale without rowcover is still alive, but badly damaged. The big leaves are crunchy and brown round the edges, and some of the inner leaves are dead. I hope it will grow back, but we won’t be able to pick that for a while. The Beedy’s Camden kale looks worse – the big leaves have died and flopped over. Not sure if it will recover.

Many of our strawberry plants look dead – very disappointing!

Our hardneck garlic and Polish White softneck tops are killed back to about one inch up from the mulch. Equally hardy, it seems.

We had the remains of a lettuce nursery bed, still holding surplus transplants from September sowings that we didn’t need for our greenhouse or hoophouse. After the 4F assault we still had life in the centers of the Winter Marvel, North Pole, Tango, Green Forest. Now only the Winter Marvel shows any signs of life. So that variety gets the prize for cold-tolerance here!

Red Round Turnip. Photo Baker Creek Heirloom Seeds — Red Round Turnip.
Photo Baker Creek Heirloom Seeds

In the hoophouse, we covered all the beds with thick rowcover every night it looked like dropping below 10F inside. Almost everything survived – we only got some minor stem freezing on some turnips and Asian greens. We have been eating Pak Choy, Tokyo Bekana, Yukina Savoy, various turnips and their greens (Hakurei, White Egg, Oasis, Red Round), also plenty of lettuce leaves, radishes, scallions, and some spinach. We lost our second sowing of spinach in there to over watering and flooding, and we are really noticing the lack right now. We’re short on spinach. We have small amounts of mizuna, Ruby Streaks, Bright Lights chard, Bulls Blood beets to add to salad mixes, and Red Russian and White Russian kale growing slowly.

In January we have taken to sowing spinach, kale and collards in a hoophouse bed to transplant outdoors in early spring. We back this up with sowing some in flats if we don’t get good emergence for some reason. This year emergence is late. Is it just late, or is there a problem? We’re holding our breath for a few more days. . .

We are not the only people tracking the effects of the unusually cold weather. The February Growing for Market magazine opens with an article by Ben Hartman “Testing the Limits of Cold Tolerance”. He farms in Goshen, Indiana, using two double-layer plastic greenhouses heated to 30F (yes. I said heated!) and two unheated. They planted kale, carrots, spinach, salad greens and arugula in their greenhouses for winter harvest. Their outdoor temperatures fell to -16F on 1/6 and 1/7. I imagine they’ve had worse since. They used mid-weight rowcover over their beds. Ben reports that baby greens and young spinach survived, as did their rosemary and their 3 fig trees (all farmers deserve some thrills!). They lost baby salad greens that had already been cut previously (all those cut edges didn’t do well). Crops in the outer beds were lost. The tips of full-grown kale leaves froze, but the plants survived.

In their unheated, single-skin plastic hoophouses, the soil froze down to 4″. They used two layers of mid-weight rowcover suspended over the crops. Despite this cold, tiny salad greens less than 1″ tall survived. Spinach survived under just one layer of rowcover. The carrot tops froze and the roots may or may not be marketable. The (uncovered) fully mature kale looks dead. The mature salad with two layers of rowcover didn’t survive.

From this experience, Ben points out that salad greens and spinach less than 1″ tall are very cold-tolerant. Spinach and kale once larger, benefit from more protection than they got this time. Beware the outer beds!

My own article in this issue is about matching crop spacing with desired goals, such as maximum yield, optimum size, or convenience for cultivation.

Andrew Mefford has written some greenhouse tips for hoophouse growers, including tomato grafting, trellising. Chris Blanchard has written the second part of his piece on growing herbs – this is about harvest and maintenance. Erin Benzakain has undertaken a 59-variety trial of celosia.

What’s still alive after two nights at 4F?

Recently I reported on which crops were still alive after two nights at 14F (-10C) and several others in the teens. We’ve now had the Arctic Vortex, which in our part of central Virginia, meant two nights at 4F, last Monday 1/6 and Tuesday 1/7 nights. How did it go?

Before the Prelude to the Big Chill, when we got 9F, I harvested the odds and ends of small cabbages left in our main patch. Quite worthwhile, I got two 5-gallon buckets. Between the 9F and the 4F nights, I decided to gather the Deadon cabbage, which we grew with January harvests in mind. There was some freeze damage, so in future I’ll say that Deadon is good down to 10F, but not lower. I got two full net bags and two more buckets of small ones. I left one smaller and one larger cabbage as sacrificial victims in the cause of better information for next year. When we got 4F, the smaller one died and the larger survived.

Deadon cabbage Credit Johnnys Selected Seeds — Deadon cabbage
Credit Johnnys Selected Seeds

One of the other gardeners harvested the last of the outdoor senposai. Another couple of buckets of tasty food.

Senposai, the Thousand Wonder Green, Credit Kathryn Simmons — Senposai, the Thousand Wonder Green,
Credit Kathryn Simmons

I took another walk round the frozen garden after the Big Chill, to see what is still alive. We have Tyee spinach under rowcover, and Vates and Beedy’s Camden kale without rowcover. They are all still alive! There’s some freeze damage in spots on the spinach leaves, but plenty of good meals still to come!

Our hardneck garlic tops suffered some damage but didn’t get killed back to the mulch level. The Polish White softneck tops are considerably smaller and they too are still alive. They will grow back if they have died.

Garlic planting in November. Credit Brittany Lewis — Garlic planting in November.
Credit Brittany Lewis

We had the remains of a lettuce nursery bed, still holding surplus transplants from September sowings that we didn’t need for our greenhouse or hoophouse. A good chance to see which ones are hardiest! Here’s the scoop:

Still alive in the centers – Winter Marvel, North Pole, Tango, Green Forest. No longer alive – Salad Bowl, Red Salad Bowl, Winter Wonder, Red Tinged Winter, Merlot, Red Sails, Outredgeous, Roman Emperor, Revolution.

At nearby Acorn Community, the home of Southern Exposure Seed Exchange, they had some young but mature heads of cabbage outdoors. The Late Flat Dutch, Early Flat Dutch and Chieftain Savoy all survived one night at 6F. (It’s usually two degrees warmer there than at Twin Oaks on winter nights).

Meanwhile I’m tracking the Blue Ridge kale grown by Clif Slade in his 43560 project at Randolph Farm, VSU. The Blue Ridge survived. It got down to 9F there. Not as cold as Louisa County! Blue Ridge is taller than the Vates we grow, and I’d like to try it here, if it can survive our winters. Otherwise not!

In the hoophouse, we covered all the beds with thick rowcover on Monday afternoon, and didn’t roll it up till Thursday, after the warmer weather returned. There was a tiny bit of freeze injury on some turnip greens that poked out the side of the rowcover, and some on some stems of Tokyo Bekana. I think the rowcover saved the crops! Also, a bad thing happened. it was very windy Monday night and the west window blew open. Argh! Of all the nights to have an open window. Memo: fix the latch to make it stronger.

I didn’t enjoy the really cold weather. I was anxious about the crops and the plumbing! But I can see two silver linings: I now have more information about cold-hardiness of various crops, and hopefully some pests will have died. Now we’re getting ready for another two cold nights, tomorrow and Wednesday.

When we placed our seed orders we gave up for this year on our quest for a reliable red cabbage of at least medium size and fairly speedy maturity (90 days or less). We’re having a red-cabbageless year. We’re still open to recommendations (OP or hybrid) – please leave a comment.