Last Updated on March 24, 2022 by Derek
Garden Lettuce Basic Information
Plant Name: Asteraceae (compositae)
Plant Family: Asteraceae (compositae)
Scientific Name: Lactuca sativa
Where did lettuce originate from?
“Designer greens,” mixtures of leafy vegetables, have become a healthy fad in the American diet. In their zest for green salads, Americans take a seat with the kings of Persia, Greece, and Rome. To the Greeks, it was “tridax,” to the Persians, “kahn.” Roman writing extolled the virtues of a dozen or more varieties of lettuce.
Cultivated lettuce is closely related to the wild lettuce, L. scariola, from which it doubtlessly descended. Although wild lettuce is found everwhere today, it appears to have originated in Asia Minor and the mid East.
Early lettuces were loose with small leaf margins and long stems. The larger-leafed and heading varieties we know today came much later. Romaine lettuce with its elongated leaves, was probably developed in Italy and is more heat tolerant than other lettuces.
Columbus was something of a gentleman farmer as well as explorer. With many other European seeds, he planted lettuce on Isabela Island (known now as Crooked Island) in Haiti in 1494 and it was quickly adopted. By the mid-1600s it became a cultivated plant in parts of South America.
European settlers undoubtedly planted lettuce in their gardens in the New World.
Lettuce planting instructions
Seeding Rate Per Foot | Scatter seed on soil surface as thinly as possible |
Seeds Per Ounce | 25,000 |
Space Between Plants | 12″ |
Planting Depth | 1/8″ |
Plant Height | Medium |
Plant Types | Leaf type Butterhead type Heading type |
Favorite Varieties | Leaf type: Red Sails, Green Ice, Oakleaf Butterhead type: Cindy, buttercrunch, prizehead Heading type: Ithaca, Salinas |
Seed Viability (Years) | 6 years |
Seed Germination | 60° F |
Germination Time | 49 days at 32° F 15 days at 41° F 7 days at 50° F 4 days at 59° F 3 days at 68° F 2 days at 77° F to 90° F |
When to plant lettuce
Lettuce should be planted in cool weather, about two weeks before the expected date of the last frost. Lettuce goes to seed when daytime temperatures average 90° F or higher.
Scatter the seeds thinly on the soil surface and cover with a 1/4″ to 1/8″ layer of soil, sand or soft potting mixture. The seed must be shallow enough to get ultraviolet light to germinate but must not get too hot nor be allowed to dry out.
Leaf lettuce is easier to grow than head lettuce, especially in a hot, desert climate. To be sweet and tender, it must grow fast in cool weather. A late-season crop planted in August has excellent flavor but can be difficult to get to germinate in hot weather.
Planting lettuce seeds
Lettuce should be thinned out when it is only an inch or two tall as crowded plants develop a strong flavor. Scatter seeds thinly in wide-row plantings and thin the first time using a rake.
Lettuce, particularly leaf lettuce, makes an attractive, edible border for flower beds and other decorative gardens. It lends itself to mixed plantings in container gardens.
Lettuce care instructions
Light Requirements | Full sun (at least six hours daily). |
Temperature Adaptations | Semi-hardy – plant a week or two before the expected date of last frost |
Acidity (pH) Tolerance | 6.8 to 6.0 pH |
Salinity (Ec) Tolerance | 1.3 |
How Pollinated | Self-pollinating |
Growth Habits | Annual |
What is the best fertilizer for lettuce?
Use an all-purpose fertilizer at the time of planting. Animal manures and compost should be added to the soil when possible.
How much water does lettuce need?
Regular irrigation: keep soil moist, but avoid overwatering. Do not let plants wilt.
Lettuce growth stages
Lettuce plants will germinate in cool soils (32° F to 40° F) and grow quickly in these conditions.
Lettuce should not be subjected to wet, dry, wet, dry soil cycles. Keep soil moist, but not soggy.
Pick when greens are young, tender and mild flavored. Begin cutting greens when they are about 2″ tall.
Head lettuce is more difficult to grow than leaf lettuce varieties. It has very particular climate, soil and cultural requirement for successful growth.
Lettuce germination Time (Days)
49 days at 32° F
15 days at 41° F
7 days at 50° F
4 days at 59° F
3 days at 68° F
2 days at 77° F to 90° F
Harvesting Lettuce
Planting to Harvest | 40 to 72 days |
Average Yield | |
Recommended planting for a family of five | 50′ of row |
Recommended Uses | Raw, stir-fry/saute, steam, braise/stew, boil |
When to harvest lettuce
Harvest leaf lettuce when the leaves are small and tender. The plant will continue to produce tender leaves even after the first harvest. Harvest butterhead lettuce when the heads are full, but still young and tender.
Heading lettuce should be picked when the heads are firm and the size reaches 6″ to 8″ in diameter.
How to store lettuce from garden
Use fresh. Can be stored for a few days in the refrigerator, but should not be allowed to dehydrate.
Make a fresh cut at the bottom of head lettuce and place in a small bowl half filled with water so that the core maintains contact with water. Leaf vegetables are best when served the same day as harvested.
Lettuce diseases and pests
Problem: Aphids
Affected Area: Leaf
Insects are found on the new stems and under leaves. The insects suck fluids from the plant, causing it to develop honey dew and turn pale yellow.
Use insecticidal soaps or spray to clean off the aphid infestation. Ladybug beetles are a natural predator and can be used for younger plants. * If you want to use pesticides, talk to your county agent about their recommendations. Can use Rotenone in early growth.
Problem: Slugs and Snails
Affected Area: Entire plant
Description: Large portions of the young plant chewed away.
Slug and snail baits allow you to control their population. Place the bait near food plants as long as they don’t come in contact with any edible portions of the crop. Snares are best when moistened, but not water logged. Slugs and snails will also be attracted by these snares from several feet away.
You can also place small piles of bait under a slightly propped up board or use containers like cottage cheese or yogurt cartons. Make sure that the container is buried about halfway so that small amounts of commercial bait can be put in it, moistened with apple juice, orange juice or water.
Cut a hole in the lid to let them access it and place the lid on it. Food plants are usually placed around edges of your garden to keep slugs out any this may help.
Problem: Beet Leafminer
Affected Area: Leaf
Maggots feed between leaf surfaces and make winding trails that damage the tissue. As they grow, they may merge to create larger areas with light-colored blotched patterns. The maggots only eat for 1 to 3 weeks before pupating in either the soil or the leaf surface and emergence of flies takes 2 to 4 weeks thereafter.
To control the population of this fly, remove and dispose of infested leaves. Floating row covers may be used to screen out the fly’s eggs. To reduce local populations host weeds like lambs quarter.
Problem: Cabbage worms, Cabbage loopers
Affected Area: Leaf
Loopers is the name of a type of caterpillar; they are generally green or greyish and take on the color of their host plant. The looper eventually develops into a white- or yellow-winged butterfly, often seen fluttering around plants. Loopers feed on the bottom side of leaves and will sometimes strip plants, leaving them bare to starve and die.
To control caterpillars, you need to spray in the spring with Bacillus thuringiensis (Bt)—available as Dipel or Thuricide. Cover the foliage, usually with remay.
Problem: Downy mildew
Affected Area: Leaf
Description: Lettuce that has an upper leaf surface with yellow-green parts and an underside with softly white roughness.
Plant lettuce varieties that are resistant to pests
Problem: Damping off
Affected Area: Seedling
Description: Strange mold found on new seedlings beginning to rot.
Solution: Preventing your lettuce from getting waterlogged.
Lettuce diseases and pests PDF
Other resources relating to growing lettuce in your garden
A guide to planting, growing & harvesting lettuce
Growing Lettuce: Planting, Growing, and Harvesting Lettuce
How to grow lettuce: plant and care for lettuce varieties | Country
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