This guide answers when to plant romaine lettuce zone 7 with timing worked out from USDA Zone 7 frost-date averages, not guesswork. Romaine is the upright, crisp-hearted lettuce behind Caesar salads, and it suits Zone 7 well because it grows fast in cool weather and tolerates a light frost. Unlike loose-leaf types it forms a tall, firm head, so it needs a little more room and a little more patience — but the reward is a head that stays crisp for days after picking. In Zone 7 you get two clear windows for it: spring, before the heat arrives, and autumn, after it leaves.
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 romaine lettuce in Zone 7
| Step | Timing in Zone 7 |
|---|---|
| Start indoors | February, about 4 weeks before the last frost |
| Direct sow outdoors | March, about 2 to 4 weeks before the last frost |
| Transplant outdoors | March to April, once seedlings have 4 to 5 true leaves |
| Autumn / second sowing | August for a autumn crop |
| Harvest | May to June (spring sowing); October to November (autumn sowing) |
The table above is the short answer. The detail matters because romaine 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 romaine lettuce
Sow seed about a quarter of an inch deep in fine, crumbly soil, and keep the seedbed evenly moist until seedlings appear in 7 to 10 days. Thin or transplant to 8 to 12 inches apart so air can move between plants — crowded romaine stays damp, and damp leaves invite slugs and rot. A light mulch of straw keeps soil cool and clean, which matters because soil splashed onto the lower leaves is the main cause of gritty salads.
Give romaine 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: romaine lettuce prefers 6.0–7.0. Space plants 8–12 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 | 60–70 |
| Spacing | 8–12 inches |
| Soil pH | 6.0–7.0 |
| Sowing method | both |
| Cold tolerance | hardy |
| Water needs | moderate |
Watering and feeding
Romaine has moderate water needs, but consistency matters more than volume: even moisture keeps the leaves sweet and crisp, while a dry spell followed by heavy watering can push plants to bolt. Water at the base in the morning so leaves dry by evening, and give about an inch of water a week in dry weather. Feed lightly — too much nitrogen makes soft, floppy growth — a dressing of compost at planting is usually enough.
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 romaine 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 romaine 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 iceberg lettuce in Zone 7, which pairs well with romaine lettuce in a Zone 7 bed.
Pests and problems
The common pests for romaine lettuce are aphids, slugs, thrips. Slugs love romaine: hand-pick them in the evening, keep the bed free of debris, and use beer traps or copper tape if they are bad. 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
Cut the whole head when it feels firm and the leaves have reached full size, usually 60 to 70 days after sowing. Cut at the base with a sharp knife in the morning, when leaves are cool and crisp, and rinse and dry the head before storing it in the fridge, where it keeps for about a week. If you only need a few leaves, pick the outer ones and let the centre keep growing. Leave the stump in the ground and many plants will regrow a small second head.
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 romaine lettuce in Zone 7?
March, about 2 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 romaine 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 romaine lettuce well, especially where garden soil is heavy or space is limited.
How long does romaine lettuce take to grow?
About 60–70 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 romaine 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 romaine 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.