Romaine is the most forgiving lettuce to harvest, because you have two good options: pick the outer leaves a few at a time and let the plant keep growing, or wait and cut the whole head at once. Both work well, and many gardeners do both — leaf-picking early in the season, then a final whole-head cut before the weather turns hot. The key is knowing when the leaves are big enough to be worth picking and when the head is ready to come out whole.
Romaine lettuce takes 60–70 days to mature, according to the Garden Grove crop data. It is a hardy vegetable in the Asteraceae family with moderate water needs, so it tolerates cool weather well and grows best in the cooler parts of the season. That hardiness means you can harvest over a long window in spring and again in autumn, but summer heat is the enemy: romaine bolts — runs to seed — when it gets hot, and bolted leaves turn bitter. For the full growing picture, see our growing guide for romaine lettuce, and use the Harvest Date Calculator to work out your picking window from your sowing date.
Romaine lettuce at a glance
| Growing factor | What romaine lettuce needs |
|---|---|
| Days to maturity | 60–70 |
| Category | vegetable |
| Family | Asteraceae |
| Cold tolerance | hardy |
| Water needs | moderate |
Signs romaine is ready to pick
For leaf picking, the sign is simple size: when the outer leaves are large enough to use — roughly the length of your hand or bigger — they are ready. You do not need to wait for a head to form. Young outer leaves are tender and mild, and picking them early gives you the sweetest eating. Taste a leaf as you go: romaine should be crisp, juicy and mildly sweet, with a pleasant crunch in the thick midrib.
For a whole head, look for a tall, upright head that feels firm and full when you squeeze it gently from the sides. The leaves should be standing upright and tightly overlapping, with the outer leaves a deep green and the inner leaves paler. A head that feels loose and open is not ready yet; a head that feels dense and solid is. The head should be well filled out but not so tight that the outer leaves are splitting.
The warning sign is bolting. When romaine starts to bolt, the centre of the plant stretches upward, the leaves become narrower and tougher, and the taste turns bitter. Once you see the centre stalk lengthening, pick what you can immediately — the leaves will only get more bitter from there. Hot weather, long days and a dry spell all push romaine toward bolting, so check the plants daily in warm weather. For the contrasting head lettuce, see our guide to when to harvest iceberg lettuce.
How to pick romaine without damaging the plant
For cut-and-come-again harvesting, pick the outer leaves one at a time, working from the outside inward. Take the largest outer leaves first, snapping or cutting each leaf at its base where it joins the stem. Always leave the centre of the plant — the growing point and the small inner leaves — untouched, because that is where new leaves come from. A good rule is never to take more than about a third of the plant's leaves at one picking, so the plant keeps enough leaf to keep growing.
For a whole head, cut the plant at its base with a clean, sharp knife, about an inch above the soil. Cut cleanly in one stroke rather than sawing, and lift the head out gently. If you cut the stump a little high and leave the roots in place, some romaine plants will regrow a small second flush of leaves from the stump — a modest bonus harvest, though never as large as the first head.
Use a clean, sharp knife or scissors for both methods. Torn leaves bruise and go limp, and a ragged cut invites rot. Pick into a basket or a clean bag, and keep the leaves out of the sun once picked.
The best time of day to harvest
Pick lettuce in the morning, when the leaves are cool, crisp and full of water from the night. Morning-picked romaine is noticeably crunchier and stays fresh longer than leaves picked in the afternoon, when the plant has lost moisture to the heat and the leaves are softer.
If you can only pick later in the day, plunge the leaves straight into a bowl of cold water for a few minutes to re-crisp them, then dry them before storing. Avoid picking when the leaves are wet from rain if you can — wet leaves are more prone to rot in storage. And never leave a basket of cut lettuce sitting in the sun while you finish other jobs; shade it or take it indoors straight away.
How often to pick
For leaf picking, harvest every few days through the season. Take the outer leaves as they reach usable size, and the plant will keep producing new leaves from the centre for weeks. This is the great advantage of romaine over head lettuce: a single plant can feed you again and again.
For whole heads, each plant gives you one main harvest, so stagger your sowing so that a few heads come ready each week rather than all at once. When a head is ready, cut it — do not leave it standing, because a mature head left in the ground is the one most likely to bolt or rot. Because romaine is hardy, a light frost will not end the season, but hard freezing and summer heat both will, so time your final harvests around your local weather. See Zone 6 romaine lettuce for an example of seasonal timing, and check your local extension service for planting dates in your area.
What happens if romaine is left too long
Romaine left too long bolts. The centre stalk shoots up, the plant puts its energy into flowers and seed, and the leaves turn bitter and tough — the milky sap in the stem is the giveaway. Bolted romaine is not poisonous, but it is unpleasant to eat raw, and no amount of washing fixes the bitterness.
A mature head left standing can also rot from the base in wet weather, especially if the outer leaves are lying on damp soil. If you find a plant has bolted, pull it out and compost it, or leave one plant to flower if you want to save seed — the flowers attract beneficial insects, and the seed is easy to collect. For the rest, pick on time.
How to store romaine
Short term, romaine keeps best in the refrigerator, washed and thoroughly dried. Wash the leaves in cold water, spin or pat them dry — wet leaves rot fast — and store them in a container or bag lined with a clean, dry cloth or paper towel, which absorbs moisture. Stored this way, romaine stays crisp for a week or more. A whole head keeps longer than loose leaves, because the outer leaves protect the inner ones, so if you are not going to use it right away, store the head whole and unwashed and wash only the leaves you need.
For longer storage, romaine does not freeze well and is best eaten fresh, so the practical way to "store" a glut is to share it, or to turn it into cooked dishes. Romaine is surprisingly good lightly grilled or wilted into soups and stir-fries, where a slightly older leaf that is past its best raw is perfectly fine. If you grow a lot of salad leaves and want to plan quantities, the Vegetable Yield Estimator can help you work out how many plants to sow next season.
Succession and continuous harvest tips
Romaine is a classic succession crop. Sow a small batch every two to three weeks through the cool season, and you will have a continuous supply instead of a single glut followed by nothing. In warm climates, sow in autumn and winter; in cooler ones, sow in spring and again in late summer for an autumn harvest.
Shade helps in warm weather: a little afternoon shade, or a row cover, can delay bolting by days or weeks. Keep the soil evenly moist with mulch, because a dry spell pushes romaine to bolt faster than almost anything else. And do not forget the cut-and-come-again method — it is the simplest succession of all, since one plant keeps producing without any re-sowing. Browse the full guides hub for more harvest timing advice, and check your local extension service for the best sowing windows in your climate.
Frequently asked questions
When is romaine lettuce ready to pick?
Outer leaves are ready once they are about hand-sized; a whole head is ready when it feels firm and full and the leaves stand tall and tightly overlapping. Maturity is typically 60–70 days from sowing.
Can you pick romaine leaves and let it keep growing?
Yes — that is cut-and-come-again harvesting. Take the outer leaves, leave the centre growing point and the inner leaves untouched, and never take more than about a third of the leaves at once. The plant will keep producing new leaves for weeks.
Why does my romaine taste bitter?
It has almost certainly started to bolt, usually because of heat, long days or a dry spell. Pick the leaves before the centre stalk lengthens, keep the soil moist, and give plants a little afternoon shade in warm weather.
How do I keep romaine crisp after picking?
Pick in the morning, wash in cold water, dry thoroughly, and store in the fridge in a container lined with a dry cloth. Wet leaves rot quickly, so drying matters as much as cooling.
How long does romaine last in the fridge?
A whole head, unwashed, keeps longer than loose leaves — often well over a week. Washed, dried leaves in a lined container stay crisp for about a week. Check your local extension service for storage advice suited to your climate.