In the gardens around greater Boston, summer crops are starting to take off. Gardens that were planted early in the season and have plenty of sun are starting to overflow with fat sugar snap peas hiding among green leaves on the vine, and tomato plants are growing big enough to be velcroed to stakes and produce their first tiny green tomatoes. Clients who have been used to going out into their gardens to harvest a salad for dinner are seeing some changes. As the days get longer and hotter, lettuce begins to go through a process known as bolting. The plant shoots up a tall stalk with flowers at the top, getting ready to go to seed. Although it may be charming to watch your lettuce flower, bitter bolting lettuce is not so charming to the palate. There are a variety of ways to slow the process, stop bolting, and extend the life of your lettuce crop farther into the summer.
One method is using the other plants in the garden to create shade. We planted new mixed greens a few weeks ago in a garden in Cambridge using the shade created by a wild and abundant crop of sugar snap peas. The peas, growing ferociously up and away from their trellising, extend out over a few squares of the garden, protecting the little lettuces from the sun and the heat.
Another method of extending the life of your lettuce is known as ‘cut and come again.’ Rather than waiting for the entire plant to grow to a harvestable size, cut the outer leaves as they grow big enough to eat. The lettuce plant will continue to grow leaves from the center out. Cutting a few leaves at a time keeps the plant from feeling mature and ready to bolt. This is an absolutely necessary step for herbs; pruning them regularly ensures that they tasty throughout the growing season.
Or, if you have had enough of salad, you can enjoy the summer crops that are about to come—peas and carrots are already big enough to eat, squash and cucumbers are growing on the vine. If you are in the mood to embrace your bolted lettuce or cabbage, some people recommend cooking the leaves in stir fry or soup. Others advocate harvesting your own lettuce seeds to plant next season!
Whatever you choices you make about your lettuce, don’t forget to make sure your whole garden is getting enough water in this heat!