Why is my lettuce growing so tall?

QUESTION: Why is my lettuce growing so tall? Can I still harvest the leaves? -Tina R

ANSWER: Lettuce plants that suddenly start stretching toward the sky and growing extra tall are likely to be bolting. In the bolting stage, a plant stops focusing so much on producing foliage and starts to turn its attention toward reproduction, sending out a flower stalk that will eventually dry to release seeds. When your lettuce bolts, the flower stalk draws energy and nutrients away from the lettuce leaves, making them more bitter and reducing their quality the longer the stalk remains on the plant. However, the leaves of bolted lettuce are edible.

When your lettuce bolts, you have three paths to choose between. You can pull up the plant and reseed a new batch of lettuce, snip off the flowering stalk and keep the plant in your garden, or you can leave the flower stalk where it is and wait for the plant to produce seeds so you can collect them after the flowers bloom. From the time bolting begins, it takes six to eight weeks for seeds to mature.

It’s impossible to keep your lettuce from bolting because bolting is a necessary part of the plant’s growth cycle. But there are some things you can do to stave bolting off as long as possible. Whenever possible, choose varieties of lettuce that are slow to bolt. Keep your plants as cool as you can—some shade helps keep lettuce healthy and slows down bolting. Trimming off the flowering stalk as soon as it appears helps to slow the process down. And when you harvest your lettuce, do it properly. For heading varieties, use clean, sterilized shears to cut the top two thirds of the plant off. When harvesting other types of lettuce, take the outer, lower leaves first and work your way up the plant. Always leave at least a third of the plant behind so it has some foliage to continue its growth. For more information on delaying the bolting process, refer to our article Preventing Bolted Lettuce.