When to Harvest Lettuce (Leaf + Head Types)

The harvest window above comes from the days-to-maturity range for lettuce. The rest of this guide is how to read each type, pick it without killing the plant, and beat the bolt.

Days to maturity by type

The "right day" depends on which lettuce you grew. Leaf types finish fast and let you nibble early. Head types take longer because they have to wrap into a full center.

Use these as windows, not deadlines. Maryland Extension puts lettuce at 40 to 80 days depending on the type, and Illinois Extension lists leaf lettuce at 50 to 60 days, butterhead at 60 to 70 days, and crisphead ready as early as 55 days. The 30 to 60 day band on most seed packets reflects that you can start picking leaf types well before they finish.

Your packet's day count is the start of the leaf window, not the finish line for heads. Soil temperature and water shift it.

How to tell it's ready

The calendar gets you close. The leaf and the head tell you the truth.

Check the cue that matches your type before you cut:

• Leaf size. For loose-leaf lettuce, the outer leaves are ready at about 3 to 4 inches. Maryland and Illinois Extension both say you can use the whole plant once it is 5 to 6 inches tall. There is no need to wait.
• Head firmness. For crisphead, squeeze gently. It should feel firm and dense, like a head from the store. Butterhead is ready when the center cups into a soft, loose head, and romaine when the leaves overlap into a head about 6 to 8 inches tall.
• Before a tall central stalk. Watch for a stalk shooting up from the center. That is bolting, and it means the plant is switching to making seed. Pick before it appears, because the leaves turn bitter once it does.

When in doubt, taste a leaf. Sweet and mild means go. Sharp and bitter means heat got to it.

How to harvest lettuce

How you cut depends on whether you want a few leaves now or the whole plant.

Leaf lettuce: cut-and-come-again. Pick the older, outer leaves and leave the small center leaves and the growing point alone. The plant keeps pushing new leaves for weeks. Maryland Extension notes that lettuce cut right above the soil will regrow and be ready to cut again in two to three weeks, so even a full cut is not the end. This is the same outer-leaf trick that keeps spinach producing.

Head lettuce: cut once at the base. For romaine, butterhead, and crisphead, slice the whole head off at the soil line with a sharp knife once it is full and firm. These do not come back, so harvest the whole row as it sizes up.

Cut in the morning. Illinois Extension says almost all vegetables are best harvested early in the morning, while the plant is cool and full of water. Lettuce picked in the cool of the day stays crisp instead of going limp.

Bolting and storage

Heat is the enemy of good lettuce. As the weather warms, growth slows, the leaves sharpen, and a seedstalk shoots up. Illinois Extension notes that high temperature or moisture stress makes lettuce bitter and bolt, and that Bibb in particular turns bitter readily above 75°F.

So in a heat wave, do not wait. If you see a stalk forming, harvest the whole plant right away before the bitterness sets in deeper.

Then cool it fast. Dry the leaves well, bag them, and refrigerate. Maryland and Clemson Extension say leaf and Bibb lettuce keep as long as four weeks when the leaves are dry before bagging, while crisphead keeps about two weeks. Illinois Extension says lettuce holds best at about 32°F and high humidity, which is your crisper drawer.

Get the spacing right next year

Crowded lettuce bolts faster and heads up poorly, because the plants compete for light and water and stress early. Give each one room and it sizes up clean and holds longer before bolting.

Leaf lettuce wants about 4 to 6 inches between plants, and head types want 10 to 12 inches. The how far apart to plant lettuce guide has the full table by type, and the Plant Spacing Calculator shows how many fit your bed.

Your next step

Lettuce is ready about 30 to 60 days after planting. Pick leaf types by the outer leaf once they hit 3 to 4 inches, cut head types at the base when they are full and firm, and do it in the cool morning before heat bolts the plant.

Planning the next sowing? Open the Plant Spacing Calculator and set your lettuce so it has room to size up and hold off the bolt. Check when to plant lettuce for spring and fall timing, and lettuce companion plants for what grows well alongside.