How to Grow LettuceDOWNLOAD FILE
May 23, 2016
Lettuce (Lactuca sativa)
- Family: Asteraceae
- Season: Cool
- Ease of growing: Easy-moderate
- Fertility needs: Low
- Water needs: Medium
- Common propagation: Seed or transplant
- Germination temperature: 35°F to 80°F
- Germination time: 2 to 15 days
- Viability: 2 to 5 years
- Direct sow: 2 to 4 weeks before last frost
- Weeks to grow transplants: 3 to 5
- Start: March to June
- Plant out: April to July
- Typical spacing: 8” to 12” in 18” to 24” rows
- Plants per square foot: 1 to 2
- Succession sow: every 2 to 3 weeks
- Days to harvest: 25 (baby) to 60 (mature) from seed; 30 to 40 from transplants
Lettuce can be divided into two major categories: leaf lettuce and head lettuce. Leaf lettuce has the greatest number of varieties available and is the most popular type for home gardens. Leaves are smooth or frilly in colors ranging from light to dark green and red to brown. Common lettuce favorites include romaine, butterhead and colorful leaf lettuce mixes. For summer plantings, it is important to select varieties with heat tolerance.
Preparation and planting
Lettuce is a cool season plant that matures quickly. It will grow on a wide variety of soils but prefers a rich sandy loam or muck. Sometimes seedling emergence is a problem on mineral soils. Provide plenty of moisture early. Before planting, incorporate a balanced fertilizer or compost.
Keep weeds managed when plants are establishing. Tight plant spacing will allow plants to quickly block sunlight from reaching the soil and help with weed suppression.
Insects: Cutworms, flea beetles, aphids, leafhoppers, slugs
Diseases: Bottom rot disease and aster yellows spread by the leafhopper insect
Harvesting and storage
Harvest head lettuce once heads reach an acceptable size and firmness. Cut off at the stem. For loose-leaf varieties, cut the outer leaves one by one when they’re large enough to use and allow the inner leaves to develop. Another method for baby lettuce is to cut all of the leaves a few inches above the soil, making sure not to cut the growing point. This process can usually be repeated one to three times at roughly 10-day intervals before quality deteriorates. Once harvested, use immediately for the best quality. You can store head lettuce for up to three weeks, although butterhead lettuce only keeps for a few days.
Developed by James Manning, Undergraduate Research Assistant, and Daniel Brainard, Vegetable Extension Specialist; MSU Department of Horticulture; Gary Heilig, MSU Extension educator.