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.

Beautiful baby lettuce mix in our hoophouse.
photo Wren Vile

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:

  1. Early Spring (Jan – Mar), 6 sowings
  2. Spring (April – May 15), 5 sowings
  3. Summer (May 15 – Aug 15), 17 sowings
  4. Fall (Aug 15 – Sept 7), 9 sowings
  5. 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

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

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 Varieties for 2017

We’ve just updated our Lettuce Varieties List for 2017, removing ones that didn’t do well last year, highlighting ones that did do well, and checking which dates work for which varieties in our climate (central Virginia, cold-hardiness zone 7).

I tried to paste in the list, but failed (I know I’ve done it successfully before!) so here’s a link and some photos

Lettuce Varieties

Reliable Red Salad Bowl lettuce, one of our stand-bys.
Photo Bridget Aleshire
Young Parris Island romaine lettuce.
photo Bridget Aleshire
Lollo Di Vino lettuce, developed by Wild Garden Seeds. Photo by https://www.wildgardenseed.com
Merlot red lettuce, from Wild Garden Seeds. Photo by https://www.wildgardenseed.com

 

 

 

 

 

 

 

When I posted my Lettuce Varieties for January article, Wanda commented on the great varieties available from Frank Morton at wildgardenseeds.com. They do have some wonderful lettuces, so I’ve included a couple of pictures of their varieties  that we grow, above.


I’m short of time today, I’m getting ready for the Southern Sustainable Agriculture Working Group Conference. Check out my Events page for more about what I’m doing there. Two brand new workshops, and book signing. I hope to see some of you bringing your dog-eared and mud-splattered copies of Sustainable Market Farming for signing on Thursday evening. I’d love some photos of well-used copies of my book!

Lettuce varieties for January, new year, fresh start

Newly germinated lettuce seedlings. Photo Kathryn Simmons
Newly germinated lettuce seedlings.
Photo Kathryn Simmons

Maybe you aren’t ready to think about sowing lettuce, but I am! In mid-January we sow a flat of four lettuce varieties, to become our first outdoor transplants. I like to choose four varieties that cover the range of colors and shapes.

Buttercrunch bibb lettuce. Photo Kathleen Slattery
Buttercrunch bibb lettuce. Photo Kathleen Slattery

I also like to choose 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!

Young Salad Bowl lettuce. Photo Bridget Aleshire
Young Salad Bowl lettuce.
Photo Bridget Aleshire

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 really head up, although it can be cut as admittedly lightweight heads. And it works fine as a leaf lettuce, to be harvested by the cut-and-come-again method. We grow New Red Fire year round, it’s that adaptable and easy-going.

New Red Fire lettuce. Photo by Bridget Aleshire
New Red Fire lettuce.
Photo by Bridget Aleshire

After last year’s success with Sword Leaf lettuce, which I wrote about last May, we have added this variety to our list of favorite lettuce varieties. But if I start those four, I won’t have a romaine and will have only one red. We haven’t found many good full-size red romaines. Rouge d’hiver is a possibility, although I wonder if it would bolt too easily (it’s more famous for growing in winter). A better choice might be Bronze Arrow (it worked well last year and we were harvesting it in early May).

We expect/intend/plan to start harvesting heads of lettuce outdoors starting 4/15. Before that we will harvesting the lettuce in the greenhouse and the hoophouse.

As you see from the top photo, we grow our outdoor lettuce as bare root transplants, starting in open flats. I’ll write about bare root transplants next week. We find it an easy, forgiving method for many crops.  For now, I’ll just talk about the lettuce. We sow in 3″ deep open wood seed flats, 12″ x 24″. We make four little furrows by pressing a 12″ plastic strip (aka a ruler!) into the seed compost. We sow the seed, label it, cover it lightly, water, then put the seeded flats in our germinator cabinet. The first flat of the year takes about 9 days to germinate. According to tables in Nancy Bubel’s Seed Starter Handbook and in Knott’s Vegetable Growers’ Handbook available free online as a pdf here, lettuce takes 7 days to germinate with a soil temperature of 50F (10C) or 15 days at 41F (5C), and only 4 days at 59F (15C).

Once the seedlings are big enough to handle, we spot them out into 4″ deep flats (also 12″ x 24″). We have a plywood dibble board with pegs evenly spaced about 2.5″ apart. You can see the offset pattern in this next photo:

Lettuce seedlings spotted out into deep flats. Photo Kathryn Simmons
Lettuce seedlings spotted out into deep flats.
Photo Kathryn Simmons

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.

We make a second sowing on 1/31. The intervals between sowings at the beginning of the year are long, because later sowings will to some extent catch up with earlier ones. Almost all crops grow faster in warmer weather (up to a point). We sow lettuce twice in February (every 14 days), then every 10 days in March, reducing the interval down to every 6 or 7 days by the summer.

As far as varieties go, we think of The Lettuce Year as having 5 seasons: Early Spring January – March, Spring April 1 – May 15, Summer May 15 – Aug 15, fall August 15 – September 7 and Winter September 8 till the end of September and our break from sowing lettuce.

Some of the early spring lettuce varieties will bolt prematurely here if sown after March 31. Examples include Bronze Arrow, Freckles, Merlot, Midnite Ruffles, Oscarde and Panisse.

Others that we like in early spring go on to be useful in spring too. All the ones mentioned as possibilities for sowing #1 are in this category, as are Green Forest, Parris Island, Kalura (three green romaines), Nancy and Sylvesta (two big green bibbs), Pirat (a red bibb), and Star Fighter (a green leaf lettuce)

Freckles lettuce has to be sown here before the end of March, or it bolts prematurely. Photo Kathryn Simmons
Freckles lettuce has to be sown here before the end of March, or it bolts prematurely.
Photo Kathryn Simmons

Lettuce in November, Twin Oaks Garden blog

Red Salad Bowl lettuce.. Photo Bridget Aleshire
Red Salad Bowl lettuce..
Photo Bridget Aleshire

I have written blogposts about growing lettuce in October, September, August, July, June and May. On October 25, I reported that we have covered our last outdoor bed of head and leaf lettuce, and an “emergency” bed of baby lettuce mix with double hoops and rowcover. Now, one month later, we are waiting out this cold snap (19F/-7C last night) until we get a mild spell to uncover those beds and finish harvesting them. We want to move the hoops and row covers to the outdoor spinach beds.

We are now harvesting only winter salad mixes, no more big bowls just of lettuce. We are using leaves from the outdoor lettuce, the outdoor lettuce mix, or leaves from the lettuce in the greenhouse, according to whatever is most ready. We chop the lettuce up as we harvest. I start with about half of the harvest bucket full of chopped lettuce. I notice that it takes 3 half-buckets of harvested greens to fill one bucket! The greens settle, and when mixed they take less space than they started out using.

Late October Starfighter and Red Salad Bowl lettuce in our hoophouse. Photo Wren Vile
Late October Starfighter and Red Salad Bowl lettuce in our hoophouse.
Photo Wren Vile

Lettuce varieties we are currently harvesting include Green Forest, Hyper Red Wave, Merlot, new Red Fire, Oscarde, Panisse, Red Salad Bowl, Red Tinged Winter, Revolution, Salad Bowl, Star Fighter, Tango, Winter Marvel and Winter Wonderland. Last winter we grew some Osborne Multileaf varieties we liked a lot. This year I learned the hard way that pelleted seed doesn’t store well. As pointed out by Johnnys Seeds in their JSS Advantage Newsletter January 2012

“Some seeds, particularly lettuce, are primed before pelleting, which begins the metabolic process leading to germination. Because some of the early steps toward germination are completed before the seed is planted, germination happens more quickly. Germination times can be 50% faster with primed seed. When seeds germinate quickly, they may avoid potential problems including soil crusting, weeds, and soilborne diseases. On the down side, primed seed doesn’t have the same storage life as unprimed seeds, so we recommend that you purchase only enough for the current season.”

Bulls Blood Beet leaves Photo Bridget Aleshire
Bulls Blood Beet leaves
Photo Bridget Aleshire

I like to mix three crop families in every salad mix: lettuce, spinach/chard/beet greens/brassicas. I also like to mix the colors and textures, so if most of that day’s lettuce leaves are green, I’ll be sure to get some Bulls Blood beet leaves or Ruby Streaks or Scarlet Frills. I don’t make the same mix every day, as variety is the spice of life!

Ruby Streaks. Photo Southern Exposure Seed Exchange
Ruby Streaks.
Photo Southern Exposure Seed Exchange

I love the taste of spinach leaves in salad, and we have lots of spinach (outdoors, in cold frames and in the hoophouse). I love the colors of baby Bright Lights and Rainbow chard. I chop those stems small – not everyone likes a big hit of chard flavor in their salad. When I harvest Bulls Blood beets I snip the stems close to the base of the plant, line up a handful of leaves, then snip off the stems just below the leaf blades, before chopping the leaves into the bucket. These stems are kind of wiry, not good food. I don’t like to leave the leaf stems on the plant for two reasons. One is that the stems “cage in” the developing plant, reducing the access to sunlight and photosynthesis. The other is that the stems die back later and rot. Better to remove them right away. I do the same with spinach.

Last month I mentioned the brassica salad mix we sowed in our hoophouse 10/2. We have made three cuts already – very good value for the tiny amount of space occupied. Mizuna, Ruby Streaks, Scarlet Frills and Golden Frills add a ferny shape and some loft to the mix. Mizuna is very mild, the other three are spicy. Other brassicas we are currently cutting small for our salad mixes include tatsoi and Russian kales (red and white). At some point, deeper in the winter, we’ll try to leave the kale alone to grow big for cooking greens. This will happen when we are shorter of cooking greens than salad items, and the kale has become more robust. Some of the crew are more hardcore than me, and include sturdier greens, like senposai. Later in the winter, other crops will come to the fore.

We also include as microgreens any thinnings from recently sowed rows of almost any greens, including radishes and turnips if they are not bristly-leaved varieties.

Traditional Chinese Scissors from Lee Valley
Traditional Chinese Scissors from Lee Valley

Our 10/24 hoophouse sowing of baby lettuce mix is almost ready to harvest – maybe in the next week or so. We have made an 11/2 second sowing of mizuna and friends, but the seedlings are still tiny, showing a big difference between the temperatures on 10/24 and those a week later on 11/2.

For cutting lettuce I like the plain steel scissors from Lee Valley. They are sturdy, easy to tighten and sharpen and ambidextrous. They are a traditional Chinese style.


Lastly, for those of you who want to know more about the Twin Oaks garden specifically, let me introduce you to the Twin Oaks Garden blog. It’s written by Wren Vile, one of the upcoming managers. I will be retiring as garden manager on March 1 2017, and Wren and Brittany will take over the day-to-day running of the garden. I won’t be going away, I’ll be around to answer questions, and I will continue to do some work in the garden, around the “edges”, rather than in the thick of the shifts. I’ll have more time for my writing and speaking on vegetable growing, and I’ll have more time off!

Brittany resting in the potato rows. Photo Wren Vile, https://twinoaksgarden.wordpress.com/
Brittany resting in the potato rows.
Photo Wren Vile, https://twinoaksgarden.wordpress.com/

Growing for Market February issue is out! So is USDA Climate Change Report!

GFM-February2013-cover-300px

The February 2013 issue of Growing for Market magazine is now available, including my new article  Making Good Decisions Under Pressure. This is the fourth article in my series about being resilient, understanding what’s going on with the plants and the weather, and knowing when to take action, is about tools to help busy farmers with complex decisions that have to be taken quickly. The middle of a hot field in mid-afternoon of the day you need to plant is not the best place to make a hard decision. It’s better to have a framework in place to lean on when the going gets tough. I talk about various decision-making techniques, clarifying whose job it is to make each decision, what resources are available, and what the impacts of the decision might be.

If that sounds abstract, I also include our sad chart “Can’t Do It All 2011”.  In early March that year, we realized we had nothing like enough experienced workers. We were looking at an overwhelming amount of work. We made a list of labor-intensive crops for possible cuts. The main point was to save us time, not just cut crops we personally disliked! We noted the decision date by each crop on the list. As each date approached we reviewed our situation. This method enabled us to make one decision at a time, in a straightforward way, and not go insane. Such a list is helpful for many types of calamity. It leaves the door open for possible upturns of fortune later in the year. It’s less distressing to take one bite at a time than to take a big decision when you already are struggling to cope with some big bad thing having happened.

This issue of GfM also has these articles:

• Lettuce varieties that tolerate heat and cold By Lynn Byczynski

• Book Reviews: The Organic Seed Grower (John Navazio) and The Art of Fermentation Sandor Katz) by Lynn Byczynski

• A new meal-planning service keeps CSA members happy by Lynn Byczynski

• Capturing information in the field to help with recordkeeping, by Chris Blanchard

• Plans for farm-built pallets that make it easy to move transplants, by Chip and Susan Planck

• What the proposed federal produce safety rules mean to you, by Lynn Byczynski

• An urban flower farmer builds a flourishing business in weddings, an interview with Jennie Love by Erin Benzakein.

Also newly arrived is the Report Climate Change and Agriculture in the United States: Effects and Adaptation (USDA Technical Bulletin 1935). I wrote about this in my post following the CFSA conference in October, where I attended a gripping workshop by Laura Lengnick, one of the authors of this report. It has 193 pages, and when I’ve read it, I’ll review it. Chapters include An Overview of U.S. Agriculture, An Overview of the Changing Climate, Climate Change Science and Agriculture, Climate Change Effects on U.S. Agricultural Production, Climate Change Effects on the Economics of U.S. Agriculture, Adapting to Climate Change, Conclusions and Research Needs, and various appendices.

Photo by Wren Vile

Photo by Wren Vile