September 24, 1999

This article will kick off a series where we discuss specific vegetables. Lettuce seems like a good candidate to start with, since it is often overlooked despite the fact that almost every gardener grows it!

Let's begin with what many of you know already. Lettuce, Lactuca sativa, is an annual plant grown for its edible leaves. While the many species of wild lettuce are also in the genus Lactuca, and are edible, only the species L. sativa is particularly palatable. But from this single species breeders have produced hundreds of varieties! These lettuces come in many shades of red and green, and several different leaf shapes and growing habits. Looseleaf, bibb, romaine, batavian, crisphead, deer tongue - the list could go on and on.

If you buy your seed from the supermarket or hardware store, chances are you are missing out on many great varieties. Mail order companies offer many more than you'll ever see on a seed rack. Johnny's catalog has several pages of lettuce. Territorial does too, plus they offer a blend in one packet so you can save money. The Cook's Garden outdoes them all though - not only do they have many different lettuces for every season and specialty, they even sell four or five separate blends! You can't go wrong with any of these companies, but I think you really should at least consider trying Cook's lettuces.

Many people believe that lettuce is sensitive to heat and daylength. While some older varieties - notably Black-Seeded Simpson - will bolt during summer's long days, most modern varieties are not particularly photoperiodic. Being an annual, lettuce will grow to a certain point and then attempt to make seed. Since summer days are so much longer than those in spring or fall, the entire growth cycle of the plant simply occurs much faster. The plant will still size up well before it tries to flower, even though the harvest window is smaller.

Lettuce likes lots of water, and prefers to grow in mild weather. Our typical spring here in the Maritime Northwest suits it perfectly. The summer weather in our corner of the world generally isn't too hot for it either, but you have to be sure to provide the plant with enough water. I have a small sprinkler I can move around the garden, so I sometimes give all my greens some extra water in between the garden's regular watering times.

Like most leafy plants, lettuce grows better with abundant nitrogen. I tend to grow it fairly densely, so I don't fertilize row by row. Before sowing I broadcast about two cups of complete organic fertilizer for each ten square feet of growing bed. In spring I also like to include about a half cup of blood meal to provide an extra nitrogen boost.

Very few pests bother lettuce. Unfortunately slugs absolutely love the stuff, and tend to prosper under ideal lettuce growing conditions. I have found that paying extra attention to keeping the lettuce bed weed-free helps keep slug levels down somewhat. Mulching the lettuce bed is not a good idea in our climate! Some people have reported success by surrounding their lettuce bed with the copper tape that's sold for slug control - but for a large garden that gets expensive. I try to control slugs just by regularly patrolling the garden, but in overly wet springs I sometimes weaken and use bait. If you choose to do this, be sure to keep the bait well away from the plants, and remember it is poisonous to your pets. I strongly recommend that you stick with metaldahyde-based baits.

Lettuce is hardier than many people think, and can handle temperatures into the low 20s (F). So for the most part it can be grown year round in our climate, although it can be zapped by the occasional winter arctic incursion.

I start the year by sowing lettuce inside under lights in early January - usually either Territorial's 'Super Gourmet' blend or Cook's 'Cutting Mix'. Rather than using seed flats, I prefer to sow thinly into 2-inch pots. I do put them over heat, but pull them off the mat as soon as I notice any plants breaking the surface. Once they've developed a few true leaves I transplant some of them so I end up with one plant per pot. Remember, if you start your lettuce this early, it's important that your growing area is cool! I have my lights set up on our unheated back porch where it doesn't usually freeze, but often dips down to about 40F at night. If you grow them in warm conditions, it's likely they'll be hammered as soon as you set them outside. Grow them hard from day one, so they'll be able to handle the late winter weather.

Around the first of March these are ready to go into the garden, under a cloche. This is also when I make my first sowing directly in the garden. In March and April I usually stick with looseleaf or romaine types - their open form allows them to tolerate dampness better than other types, so they grow faster and healthier. I sow more right around the first of every month, up until August. This succession planting provides us with high quality lettuce for most of the year. Most months I sow just a couple rows, but in August I put in a lot more since those plants have to cover all of fall and winter.

From April until late October, lettuce does great outside without any protection. But during winter it holds up much better if it's kept under cover - while it does like water, it doesn't tolerate endless drenching! I've found it does quite well in winter inside my PVC hoophouse - better than under a cloche, because of air circulation - especially if I keep a blanket (or doubled-up rowcover) handy for those rare nights that dip into the teens. Like most other winter vegetables, though, lettuce doesn't really grow in the winter - it just sits there. This means you have to think ahead. When you make your last sowing in August, try to figure out how many plants will get you through the fall and winter ahead of time.

I have noticed that even among the lettuces generally recommended for winter harvest, some types handle our winter weather better than others. Normally I just plant blends because I like having the variation, but this year I am attempting to quantify the winter performance of the individual varieties. I'm growing six varieties of lettuce that are supposed to be good choices for winter - Brune d'Hiver, Arctic King, Winter Marvel, Integrata Red, Winter Density, and Rougette du Midi. As a control I'm also growing a row of Territorial's 'Super Gourmet Salad Blend', which handles winter fairly well. Cold hardiness is important, of course, but how well these cope with constant dampness will probably be an even bigger factor. I will report the results sometime this winter.


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This page was last updated November 18, 2013