How to Tell When Lettuce Is Ripe

Wait until lettuce is fully ripe before harvesting.

Lettuce from your grocery store is plucked from the ground at the peak of ripeness -- there's no guessing. The ripeness dilemma is only an issue once you start to grow your own lettuce. It's up to you to determine when your lettuce crop is ready for harvest. Lettuce maturity is based solely on head development, but head development varies by type.

Instructions

1. Read seed packets to estimate harvest dates and determine when your lettuce will ripen. Dates for full maturity typically range from 50 to 90 days.

2. Pick leaf lettuce varieties as soon as the leaves are large enough to use in a salad. These varieties are harvested by the leaf and ripen as soon as you can use them. They continue to grow throughout the season to produce more lettuce leaves.

3. Harvest romaine-type lettuce, those with a tall, loose, bunched head, when the head is firm and has about 30 to 35 developed leaves.

4. Pick crisphead lettuce when the head feels firm.

Tips & Warnings

• Harvest all lettuce types before temperatures maintain averages over 70 degrees Fahrenheit. At this temperature, lettuce becomes bitter and starts to turn to seed.

• Store lettuce in the refrigerator in the coolest part, usually on the first shelf against the back wall.

• Do not store lettuce with pears, apples or bananas; they produce ethylene gas, which causes brown spots and decay on the lettuce.

• Throw away any lettuce with black spots or a slimy appearance; the black spots usually indicate mold growth.

References

• Washington State University Extension; When to Harvest Home Grown Vegetables; George Pinyuh; 1981
• University of Illinois Extension: Lettuce
• Ontario Ministry of Agriculture; Harvest Tips for Summer Cabbage, Cauliflower and Romaine Lettuce; Jennifer Allen; June 2007
• WalterReeves.com: Lettuce