Book 29, Question 46
Why do lettuce and spinach suddenly shoot up and turn bitter?
When days get long and hot, lettuce, spinach, and radishes may send up a tall flower stalk.
This is called bolting. The plant is trying to make seeds before summer ends. Once it bolts, the leaves often taste bitter. Gardeners grow these crops in cool spring or fall, provide shade, and keep soil moist to delay bolting.