This guide answers when to plant iceberg lettuce zone 7 with timing worked out from USDA Zone 7 frost-date averages, not guesswork. Iceberg is the cool, crunchy lettuce of wedges and burgers, and it is the most demanding lettuce to grow in Zone 7 because it needs a long, cool run to form a tight head. Heat is its enemy: once warm weather arrives it bolts, turning bitter and sending up a flower stalk. That makes timing everything — sow early, give it rich soil and steady water, and you can grow heads as good as any shop-bought one.
Zone 7 at a glance
Zone 7 covers areas where average annual minimum temperatures run 0 to 10°F. The average last spring frost falls in the Mar 15–Apr 1 range and the average first autumn frost in the Nov 1–15 range — these are USDA zone averages from USDA and NOAA frost records, not exact dates for any one garden, so check your local extension service before planting tender crops outside. Use the frost date calculator to work out dates for your own garden, and browse the planting calendar hub for the full Zone 7 year.
When to plant iceberg lettuce in Zone 7
| Step | Timing in Zone 7 |
|---|---|
| Start indoors | January to February, about 6 weeks before the last frost |
| Direct sow outdoors | February to March, about 3 to 4 weeks before the last frost |
| Transplant outdoors | March to April, once seedlings are sturdy |
| Autumn / second sowing | July to August for a autumn crop |
| Harvest | June (spring sowing); October to November (autumn sowing) |
The table above is the short answer. The detail matters because iceberg lettuce is hardy — a hardy crop that tolerates light frost, so it can go out weeks before the last frost. Start indoors when the table says so, using the seed-starting calculator to count back from your last frost, and harden seedlings off for a week before they go outside. The Zone 7 March guide shows what else is happening in the garden in that month.
How to plant iceberg lettuce
Sow seed about a quarter of an inch deep and keep the seedbed moist until seedlings appear in 7 to 10 days. Iceberg needs generous spacing — 12 to 18 inches between plants — because a tight head needs room and air. In Zone 7, starting indoors in January to February and transplanting in March to April gives plants the cool head start they need; direct-sown plants work too, but they mature later and closer to the heat. Mulch to keep the soil cool.
Give iceberg lettuce full sun — at least six hours of direct sun a day for full-sun crops, or morning sun with afternoon shade where part shade is listed. Prepare the bed by forking in compost and removing stones and weeds, and check the soil pH: iceberg lettuce prefers 6.0–7.0. Space plants 12–18 inches apart — the spacing in the table below — and sow seed at the depth on the packet, keeping the seedbed moist until germination, which takes 7–10 days.
| Fact | Range |
|---|---|
| Sun | full sun |
| Days to germination | 7–10 |
| Days to maturity | 70–85 |
| Spacing | 12–18 inches |
| Soil pH | 6.0–7.0 |
| Sowing method | both |
| Cold tolerance | hardy |
| Water needs | moderate |
Watering and feeding
Iceberg has moderate water needs, but steady moisture is essential for a firm head — dry spells followed by heavy watering can cause tipburn, the brown edges on inner leaves. Water at the base, in the morning, aiming for about an inch a week in dry weather. Feed with compost at planting and a light liquid feed midway; avoid heavy nitrogen late in growth, which makes soft heads that rot from the inside.
A layer of mulch — straw, shredded leaves or compost — helps on both fronts: it holds moisture in the soil, keeps roots cool, and stops soil splashing onto leaves and fruit. Keep mulch a few inches away from stems so it does not trap damp against them.
Companion plants and rotation
Good companions for iceberg lettuce include marigolds, basil, onions, lettuce. Use the companion planting finder to plan combinations for your whole bed. Rotate crops each year: do not plant iceberg lettuce where the same family grew last year, and keep a simple note of what grew where so you can rotate properly next season. Also see our guide to when to plant romaine lettuce in Zone 7, which pairs well with iceberg lettuce in a Zone 7 bed.
Pests and problems
The common pests for iceberg lettuce are aphids, slugs, thrips. Tipburn is the main problem — brown leaf edges caused by uneven watering or calcium uptake — so keep watering steady rather than reaching for a spray. Check plants weekly, looking under leaves as well as on top — most problems are easy to deal with if caught early. Good air flow helps: do not crowd plants, water at the base rather than over the leaves, and clear away dead leaves and debris where pests hide.
Harvesting and storing
Harvest when the head feels firm and solid when you squeeze it gently, usually 70 to 85 days after sowing. Cut at the base in the morning, remove any damaged outer leaves, and store the head whole and unwashed in the fridge, where it keeps for one to two weeks. Harvest promptly once heads are firm — leaving them in warming soil invites bolting and rot.
For the best flavour, harvest in the morning, when plants are cool and their moisture and oils are at their best, and use a sharp knife or scissors for a clean cut that heals quickly.
Frequently asked questions
When should I plant iceberg lettuce in Zone 7?
February to March, about 3 to 4 weeks before the last frost. As a rule, work back from the average last frost range of Mar 15–Apr 1 for spring planting, and back from the average first frost range of Nov 1–15 for autumn planting. These are zone averages, so check your local extension service for your area.
Can I grow iceberg lettuce in containers?
Yes, in most cases — choose a pot at least 12 inches deep with drainage holes, fill it with good potting mix, and water more often than beds, since pots dry out faster. Container growing suits iceberg lettuce well, especially where garden soil is heavy or space is limited.
How long does iceberg lettuce take to grow?
About 70–85 days to maturity from sowing or transplanting, depending on variety and weather. Germination takes 7–10 days. Warm, sunny weather speeds growth; cold or cloudy weather slows it, so treat these as ranges, not exact dates.
What soil pH does iceberg lettuce need?
A pH of 6.0–7.0 is ideal. Test your soil before planting and amend it if needed — your local extension service can test a sample and advise on what to add.
What grows well with iceberg lettuce?
Good companions include marigolds, basil, onions, lettuce. Avoid planting it where the same family grew last year, and give it the spacing and sun listed in the table above so companions do not crowd it out.