Lettuce

When to Plant Lettuce

• Direct sowing in the garden is recommended as soon as the ground can be worked. Sow 2 to 4 weeks before your last spring frost date. Soil temperatures need to reach 40°F (4°C), though seeds germinate best at 55 to 65°F (13 to 18°C). Seedlings will typically emerge in 7 to 10 days.
• If you want an even earlier start, sow them under cover 4 to 6 weeks before your last frost with plenty of lights, such as indoors or in a greenhouse, hoop house or cold frame. If it’s fairly gloomy, you may get the best results by growing them under grow lights to start with.
• Nursery-bought lettuce transplants should be planted close to your last frost-free date. Transplants that were started indoors may be planted 2 to 3 weeks earlier after they are properly hardened off.
• You can help transplants along at the start of the season by covering them with a temporary cloche made from bottomless milk cartons or plastic bottles – demo of this. These will keep the chill off your seedlings just enough to help them acclimatize. Newly planted lettuces may also be helped with a simple covering of row cover or fleece.
• Continue sowing every few weeks to enjoy a steady stream of leaves; we suggest small sowings each time, so you’re not overwhelmed!
• In most regions, it’s possible to plant another crop of lettuce in the fall or even early winter. See our Planting Calendar for planting dates.
• Tip: To plant a fall crop, create cool soil in late August by moistening the ground and covering it with a bale of straw. A week later, the soil under the bale will be about 10°F (6°C) cooler than the rest of the garden. Sow a three-foot row of lettuce seeds every couple of weeks—just rotate the straw bale around the garden.

Choosing and Preparing a Planting Site

• Select a sunny spot for the best growth. Ideally, the plants should get at least 6 hours of sun per day, though lettuce will still grow if given less than that.
• The soil should be loose and drain well, so that it’s moist without staying soggy.
• To keep the soil fertile, work in composted organic matter about one week before you seed or transplant.
• Since the seed is so small, a well-tilled seedbed is essential. Stones and large clods of dirt will inhibit germination.
• Lettuce does not compete well with weeds. Spacing lettuce close together will help to control weeds. 
• Rotating locations from year to year helps to reduce the occurrence of most diseases.
• Read more about preparing soil for planting.

How to Plant Lettuce

• Seeds should be planted 1/8 to 1/4 of an inch deep. Lettuce seeds need light to germinate, so don’t sow them too deep. 
• Seedlings can be thinned when they have 3 to 4 true leaves. You can eat what you thin out, too.
• Transplants should have 4 to 6 mature leaves and a well-developed root system before being planting into the garden.
• For either seeded or transplanted lettuce, leave 12 to 15 inches between each planting row. Here are guidelines for different lettuce types:
  • Loose-leaf lettuce: Plant or thin to 4 inches apart.
  • Romaine (cos) and butterhead (loose-head, Bibb, Boston) lettuce: Plant or thin to 8 inches apart.
  • Crisphead (iceberg) lettuce: Plant or thin to 16 inches apart.
• Water thoroughly at time of transplanting.
• Consider planting rows of chives or garlic between your lettuce to control aphids. They act as “barrier plants” for the lettuce.
• If you’d like to grow your lettuce inside your home, check out these tips for growing lettuce indoors.