In The Garden With Urban Harvest:
For An Easy, Rewarding Treat, Try Lettuce

By Bob Randall

If you like salads, there are few crops that will reward you with easier quality production than will lettuce. I once estimated the materials cost of growing lettuce in our area at 10 heads for a penny, and I estimated the labor in very dry years at less than five minutes per head.

Lettuce can also be one of the most beautiful plants you grow. Choose various colors from deep red to deep green, and plant a mural or patchwork quilt to cover the bed. Be sure to label the different ones so you know what did well in the soil and in the salad bowl.

Lettuce is a mainstay of the cool season diet, but it doesn’t grow well in very cold weather, so except in inner city Houston where it can be planted all winter, it needs to be planted after temperatures have cooled in the fall or before they get very warm in the spring. Lettuce will usually do well down to the 22-25˚, but below that it will need a blanket of leaves, hay or even an actual blanket. So lettuce is very easy for the small grower in the city, but may be a challenge some years in colder parts of the region during December and January.

One key to understanding lettuce is that the seeds generally do not sprout until the surface temperature of the soil drops below 75-80˚. So shading the mid fall seedbed can help get things started in the fall, but waiting until day time highs drop below 80˚ in the last week of October is easier. This is particularly true because lettuce grows best at 60-65˚, and grows well down to 45˚, but has trouble absorbing nutrients when it is hot. So it gets bitter in hot weather unless picked very young.

What You Need
You can grow lettuce almost anywhere you have a raised bed with good sandy loam free of vegetation, and an adequate supply of water during dry spells. Until the seeds germinate, you will need to water twice a day, especially because of the drought we’ve been having. Lettuce does not need full sun, but likes it. I don’t know how much shade it can tolerate, but it might produce even in bright shade and will grow in pots. I recommend balanced organic fertilizers such as Microlife, Soil Food or Earth Essentials for the best results.

Varieties of Lettuce
There may be over one thousand varieties of lettuce suitable for planting here. You can get many good varieties at Urban Harvest, your neighborhood garden center, or do a search on the internet.

Leaf lettuces mature in 40-45 days from seed, and their leaves can be eaten in just five weeks so they are usually my first lettuce of the fall. They are rarely found in markets because they ship poorly. Good ones include: Black seeded Simpson, oak leaf and red sails, Lolla Rossa, and Red Deer Tongue. Revolution is clearly the reddest of them all and Green Ice is very green.

Butterhead types consist of green leaves wrapped loosely around a soft yellow center. They are tender and therefore cannot be handled by lettuce harvesting machines so are less common in the markets. They are more heat resistant and take about 75 days to mature, so they are best here for planting in mid January for an April harvest or in fall if you want a head. Bibb, white Boston, Early Dutch Butterhead, or Tom Thumb have merit. You can also try Buttercrunch, Red Boston and Ostintata, Green Mignonette, Pirat, and Mantilla.

Traditional Crispheads are also known as Icebergs. They form a compact ball head of tight, crisp nutrition-less leaves and are mainly important in the market trade because they keep a long time and ship well. The well-known ones usually grow poorly here because the heads rot in warm humid weather. The more heat tolerant Bavarian crispheads like Red Grenoble are much better tasting.

Cos or Romaine lettuces are much easier head lettuces to grow here. This type originated on the Greek Island of Cos, then was grown by the Romans so is called Romaine by the French who have developed it. They take 65-70 days and are best grown in fall. Once picked, they are durable. Valmaine, Rouge d’Hiver, and most other varieties grow well here. There are also intermediates between butterheads and romaines. Of these, Winter Density may be the best overall variety for the home gardener. It is delicious, nutritious, heat and cold resistant. Cracquelle de Midi and Little Gem are two other good ones.

The deeper colored lettuces are high in the phytochemicals, fiber, caretenoids, foliate, Vitamin C and have significant potassium. But their nutritional value differs by type: looseleaf lettuce has six times and butterhead lettuce four times the nutrients of iceberg. Romaine is a fair source of the cataract and macular degeneration prevention phytochemicals lutein and zeaxanthin.

Planting & Care

There are more than 2,400 seeds in just one-tenth of an ounce of lettuce seed, and if stored in a cool dry jar in the refrigerator, they may last several years. Seeds die quickly in heat.

After you have cleared and fertilized soil, just sprinkle the seeds lightly on the soil surface and then gently tamp the earth where they fell with your hand. Then water well, label, and keep watered through the life of the plants.

Once the seedlings are 1-2 inches high, when late in the day in cool weather, move ones that came up closer than four inches apart to empty areas and water very well. Weed and thin until there are a few inches between each plant and then enjoy eating the thinnings. As lettuces develop, they will need to be thinned to wider spacings. Leaf lettuces need no thinning but will do well at 8 inches, as will Romaine. Butterheads other than the tiny Tom Thumb need 9-12 inch spacing at maturity, and iceberg/crispheads one foot or more.

Lettuce is best picked early in the morning and cooled rapidly.

So whether you have a yard or a container garden on your apartment balcony, plant some different lettuce varieties and enjoy a fresh salad. Toss in some radishes and edible flowers. Feel proud of yourself for growing and eating homegrown fresh produce.

Bob Randall, Ph.D. retired in 2008 as Executive Director of Urban Harvest and is the author of Year Round Vege-tables, Fruits and Flowers for Metro-Houston. Contact him at

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