Lettuce is a cool-season crop that grows well in spring and fall in most areas.This crop is great for beginners; once the land is ready to be cultivated, the seeds can be easily sown directly into the soil. Because lettuce grows quickly, it's best to sow a small number of seeds at a time, and stagger them.
How to Grow:
- Lettuce is a cool-climate crop that thrives in temperatures ranging from 60-65 degrees Fahrenheit. Cold-adapted varieties can survive much lower temperatures.
- Direct sowing is recommended. Sow seeds in the ground 2 to 4 weeks before your last spring frost date.
- Since the seeds are small, a well-till seedbed is essential. Stones and large pieces of soil will inhibit germination.
- Sow seeds 1/8 to 1/4 inch deep. Lettuce seeds need light to germinate, so don't plant them too deep.
- Seeds can be sown in single or wide rows (scattered leaf varieties are best). When planting, thin out seedlings 1 to 2 inches tall for proper spacing.
- The spacing between plants depends on the variety:
- Loose Leaf Lettuce: Plant or as thin as 4 inches.
- Romaine (cos) and butter-head (loose-head, Bibb, Boston) lettuce: planted or as thin as 8 inches.
- Crisphead Lettuce: Plant or as thin as 16 inches.
- Space the rows of lettuce 12 to 15 inches apart
- Sow additional seeds every 2 weeks for a continuous harvest.
- Consider planting rows of chives or garlic between lettuce to control aphids. They act as "barrier plants" for lettuce.
- Water thoroughly with a misting nozzle when transplanting or planting.
- Lettuce will generally fail to germinate if the temperature exceeds 80 degrees Fahrenheit. If the seeds germinate in the refrigerator for 4-6 days, you can plant lettuce in late summer or early fall when the air is still hot. Another method is to soak the seeds in 10% bleach at 40-60 degrees F for 2 hours, then rinse with water 4 times. This method increases the speed and quantity of germination. Another way is to keep the soil cool with burlap or planks; remove the cover immediately after germination to keep grasshoppers and other pests from enjoying the shady sprouts!
- Bolting is a common problem that’s caused by warm temperatures (over 70°F/20°C) or changes in day length. When a lettuce plant bolts, it starts to produce a central stem and seed stalk, and leaves take on a bitter flavor.
- To delay bolting, cover plants with a shade cloth so that they get filtered light. Be sure to maintain watering throughout the warmest parts of the growing season, too.
Harvest and Flavor Notes:
- Lettuce harvested in the morning may have 2-1/2 times more glucose than lettuce harvested earlier in the afternoon. For best quality and maximum sweetness before 7-8am, especially in summer.
Insect Pests and Diseases:
- Consider planting rows of chives or garlic between your lettuce to control aphids.They act as “barrier plants” for the lettuce.