Winter lettuce and other salad crops

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

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

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

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

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

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

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

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

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

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

Buttercrunch Bibb lettuce in December. Photo Kathleen Slattery

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

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

Lettuce growing in our greenhouse in November.
Photo Wren Vile

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Bulls Blood Beet leaves
Photo Bridget Aleshire

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

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

 

Saving watermelon seed, rainy day reading, Heritage Harvest Festival

Scooping watermelon seed.
Photo Pam Dawling

I wrote recently about saving tomato seed, and here I’ll write about extracting watermelon seed. We grow Crimson Sweet Virginia Select, which we sell to Southern Exposure Seed Exchange. I walk through the patch with a grease pencil (china marker) in July when the melons are forming and write numbers on 40 nice-looking big melons. I’m selecting for earliness, size, disease resistance and flavor.

Selected watermelon with an identifying number.
Photo Nina Gentle

Once the melons start to ripen, I go out to the plot once a week with my trusty garden cart and a collection of clean buckets, a notebook and pen, a big knife, a large slotted spoon, a couple of damp rags, a bottle of water and a big straw hat. I start testing the numbered ones for ripeness. If they are ripe I decide if they are seed-worthy, demoting any with dead vines (not disease-resistant!) or too small. I find promising replacements for any I decide not to save seed from, and number those.

Garden cart with supplies for watermelon seed collection.
Photo Pam Dawling

When I have a good one, I cut it in half and scoop the heart out into a very clean bucket. I taste a piece (that’s the “good flavor” test). These days they all seem to taste good, but the first few years of seed selection, I had some I didn’t like much, so I didn’t save seed from those. See the first photo for the scooping task. Once the heart is scooped out, there is a layer of flesh with seeds in, which I scoop out into a moderately clean bucket. Then a layer of flesh without seeds for the food bucket.

Watermelon seed bucket and food bucket.
Photo Pam Dawling

In the blue bucket is my “dry zone” with my notebook. I write down which melons I harvested, any I discarded, any new ones I added, and how many are left to find in the coming weeks. Generally I harvest 7-10 watermelons per week, generating two buckets of fruit and two half-buckets of seeds. The watermelon seeds are fermented for four or five days, then washed – just like processing tomato seeds I wrote about last week.

Dried watermelon seeds in a paper bag.
Photo Pam Dawling

I harvest 5 or 6 times, from Late July to early September. I don’t want to be selecting for late-ripening melons so I stop harvesting seed long before the fruits are over.


My most recent blog post for Mother Earth News is about repairing garden hoses, most of which you already read about here. It’s in the DIY blog this time (most of my posts go in the Organic Gardening blog). I just heard some numbers for how various of my Mother Earth News blogposts this year are doing, and the big favorite topic is Growing Lettuce Year Round: Succession Planting for a Continuous Supply: 10,924 views! Growing Winter Lettuce: 4,620 views, is second favorite. people sure do love lettuce! Other popular topics this year have been Winter Hoop House Harvest Schedule, Using Open Flats (Seed Trays) to Grow Sturdy Seedlings EasilyHeat-Tolerant Eggplant Varieties, and Planting Leeks. 

How to harvest garlic scapes.
Photo Wren Vile

When I look to see which posts on this blog people visit most often, I see that garlic harvesting and garlic scapes are very popular, as are posts about sweet potatoes.


Sometimes I post links to my slideshows, but here’s a You Tube I’ve been meaning to tell you about. This is my presentation of Succession Planting for Continuous Vegetable Harvests at New Country Organics.


The September Growing for Market is out. The cover article, by Carolina Lees, advocating a Farmer Retreat. This is a wintertime regional gathering of farmers, with scheduled time for discussion and also for casual hanging-out. No imported speakers! The author is in Oregon, and envy-inducing photos of the beach-side retreat are included. But, what a good idea!

David Ross writes about grower relationships with wholesalers. Shawn Jadrnicek, author of The Bio-Integrated Farm: A Reveolutionary Permaculture-Based System . . .  writes about mulching and crimping techniques for no-till vegetables, including how to have weed-free cover crops, and get the right machinery to roll and crimp them. he uses a manure spreader to spread tree leaf mulch, and shows photos of a very tidy farm.

Rowan Steele writes about obtaining used silage tarps (as advocated by Jean-Martin Fortier) for covering beds to control weeds organically. Rowan writes about how to use the tarps and suggests coordinating a used silage tarp delivery for your small farm community. Contact Travis Quirk at the nonprofit Simply Agriculture Solutions Inc. in Saskatoon, Saskatchewan (travis@simplyag.ca).  The tarps may be delivered for the cost of shipping. Canadian farmers are required to recycle their “grain bags”, but it’s hard for them to find a recycling facility in Canada, so the plastics are sent to the US. They are happy to be able to divert the material for a second use. Sounds great to me!

Jane Tanner writes about William’s WIldflowers, a floral design business run by two sisters, using lots of native flowers, especially perennials, for weddings and other formal occasions.


See you at the Heritage Harvest Festival on Friday September 8 (my premium workshop on growing sweet potatoes from start to finish) or Saturday (strolling around). Last time I looked there were still tickets available for my workshop ($20)

Heritage Harvest Festival