Lettuce is one of the most rewarding crops for beginner and experienced gardeners alike. It grows quickly, tolerates frost, and produces abundantly in cool weather. The key is timing — lettuce bolts (goes to seed) in heat, so it's a spring and fall crop in most climates.
With succession planting every 2–3 weeks, you can harvest fresh salad greens from your garden for months. Cut-and-come-again varieties like leaf lettuce give you even more value, re-growing multiple times from a single planting.
Lettuce grows well beneath taller crops that provide afternoon shade — interplanting under tomatoes or pole beans can extend lettuce harvest by 2–3 weeks in warm weather by reducing heat stress. Its shallow roots do not compete significantly with deep-rooted neighbors. The planner helps you identify shade opportunities from taller crops for heat-sensitive lettuce succession plantings.
Bitterness develops when lettuce bolts (flowers) in heat or stress. Harvest before flowering begins and keep plants well-watered. Some heat-tolerant varieties resist bitterness longer.
Harvest leaf lettuce anytime after it's a few inches tall. Head lettuce is ready when the head feels firm. Both types should be harvested before the plant starts to send up a flower stalk.
Yes! Lettuce grows well under grow lights indoors. You need at least 12–14 hours of light per day. Choose compact varieties and harvest frequently for continuous production.
Keep plants cool and well-watered. Use shade cloth in warmer weather. Plant bolt-resistant varieties in summer. Time your plantings so they mature in cool weather, not at the peak of summer heat.
Absolutely — lettuce is one of the best container vegetables. Use a container at least 6 inches deep with drainage holes. Keep consistently moist and harvest regularly.
Lettuce produces bitter latex compounds in response to heat and long days as part of its bolting process. Temperatures above 75°F and day lengths above 14 hours trigger bitter flavor and eventual bolting (flower stalk production). Plant lettuce in early spring (Zone 5: late March–April) or fall (August–September) to avoid summer conditions. Shade cloth that reduces direct afternoon sun by 30–50% can extend spring lettuce by 2–3 weeks in warm zones.
Batavian and oak-leaf types are the most heat-tolerant lettuce varieties, bolting 2–3 weeks later than butterhead or romaine types under the same conditions. Jericho (a romaine type from the Negev desert) has excellent heat tolerance for a romaine. Nevada and Sierra are reliable Batavian types. Even heat-tolerant varieties ultimately bolt in sustained summer heat — timing is more important than variety selection for regions with genuine summer heat in Zones 6–9.
Lettuce grows well in partial shade — 3–4 hours of direct sun plus bright indirect light is sufficient for productive growth, though 6 hours produces larger leaves more quickly. Partial shade from taller crops (tomatoes, trellised beans) reduces heat stress and extends harvest by 2–3 weeks in late spring. South-facing beds with afternoon shade from a fence or taller plants are ideal for extending spring lettuce past the point when full-sun beds have bolted.
Cut-and-come-again harvesting extends a single lettuce planting significantly. Remove outer leaves starting at 4–6 inches tall, leaving the growing center intact. New leaves grow from the center continuously until the plant bolts. For romaine and butterhead types, you can also cut the entire head 1–2 inches above the soil surface — many varieties will regrow from the crown for a second, smaller harvest. Succession planting every 3 weeks provides a continuous supply through the growing season.
Premature bolting is triggered by long days (above 14 hours), heat above 75°F sustained over several days, and drought stress. In Zone 5–6, mid-May through July is the high-bolt-risk window. Prevention strategies: choose slow-to-bolt varieties, plant lettuce where it receives afternoon shade, water consistently to avoid drought stress, and plan the final spring succession planting to be in the ground by April 15 in Zone 5 (or earlier in warmer zones) to ensure harvest before conditions trigger bolting.