How to grow lettuce
Family Asteraceae. Hardy to USDA hardiness zone 3a+ (U.S. Department of Agriculture). Full sun to part shade. Ready in 30-60 days.
Sun
Full sun to part shade
Spacing
8-12 in
Days to harvest
30-60 days
Hardiness
Zone 3a+
What growers actually recorded
Loading zone 7b results…
When to plant lettuce
- Start indoors: ~4 weeks before last frost.
- Transplant out: ~-2 weeks after last frost.
- Direct sow: ~-4 weeks after last frost.
Companion plants for lettuce
Plant with: Radish, Carrot, Onion, Strawberry.
Avoid near: Broccoli (competes for water).
Common pests & problems
Slugs, aphids. Water in the morning.
Feeding & fertilizer
N-P-K ratio: Balanced 5-5-5 with steady N
Organic options: Compost tea every 2 wks · Fish emulsion between cuttings · Aged manure in bed prep
When to feed: Light and steady. Lettuce wants constant slow N to stay tender and mild.
Watch for: Bitter greens = heat or under-water, not fertilizer.
N = nitrogen (leaves), P = phosphorus (roots and flowers), K = potassium (fruit and disease resistance). How to read a fertilizer label →
Grower's tip
Succession sow every 2 weeks. Harvest outer leaves for a cut-and-come-again supply.
When to plant lettuce in your zone
Free month-by-month sowing and transplanting lists, built from frost dates for your USDA (United States Department of Agriculture) hardiness zone.
Soil & water for lettuce
Soil & pH
6.0-7.0
Rich, moisture-retentive loam. Lettuce fails in dry, hot beds.
Compost + a light dressing of blood meal. Consistent nitrogen = tender, sweet leaves.
Watering
1-1.5 in / week; more in heat
Morning overhead is fine; keep foliage dry by nightfall to prevent bottom rot.
Taste-test a leaf mid-morning. If it's bitter and the weather is hot, harvest before 7 AM and provide shade. If it's bitter and the weather is cool, the soil is too dry or too old for the plant.
Knowing when to harvest
- Baby leaves: 3-4 in tall for cut-and-come-again.
- Full heads: firm center for crispheads; loose center for romaine and butterheads.
- Harvest at dawn for the crispest, sweetest leaves.
Storing & keeping
Wash, spin dry, wrap in a towel in a bag in the crisper: 7-10 days. Do not freeze.
What to expect
Per plant: 6-12 oz head; multiple cuttings from leaf types
Per sq ft: 4-9 heads per sq ft
Troubleshooting lettuce
Bolting (tall stalk + bitter leaves)
Likely cause: Days over 80°F or 14+ hr day length
What to do: Grow spring & fall; shade cloth in summer; choose bolt-resistant varieties.
Tip burn (brown edges)
Likely cause: Fast growth + calcium can't keep up in heat
What to do: Even watering; light overhead sprinkles during heat waves.
Varieties worth growing
Salanova (heading loose-leaf)
Single-cut multileaf; the market grower's default.
Jericho (romaine)
Heat-tolerant; bolts late.
Buttercrunch
Reliable, tender, tolerates a lot of imperfection.
Growing lettuce in containers
6 in deep pot minimum; window-boxes work great with succession seeding every 2 weeks.
Nutrition
Vitamin K, folate, lutein. Most calories in the leaves come from water.
Common questions
Can I grow lettuce in summer?
In zone 6+, yes. Under 30-50% shade cloth with bolt-resistant varieties and consistent water.
Where these numbers come from
- USDA Plant Hardiness Zone Map (2023 revision). Zone assignment and the 30-year normals behind every cold-hardiness figure.
- NOAA NCEI 1991-2020 Climate Normals. Frost dates, growing-season length, and the probability bands on both.
- Cornell, UMN, and UC Davis Cooperative Extension crop guides. Spacing, days to maturity, soil pH targets, and per-plant yield ranges.
- USDA FSIS / FDA Produce Safety guidance. Wash, cure, and cold-storage handling numbers.
Ranges are regional guidance, not a promise for your yard. Your own logged results always override the published range.