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
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
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
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
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
Learn about gardening classes and more at
or phone 713-880-5540.