It seems unfair—just when we really need lettuce as the foundation of a summer salad, the lettuce wants to pack up and spend its summer at Lake Tahoe (or some other cool spot). Here’s how you can have your lettuce and heat it too. Horses bolt and so does lettuce Lettuce prefers the cool days of spring and fall with air temperatures in the 60s. When the weather warms up lettuce will often bolt right out of your garden bed. In the world of lettuce, bolting means that the plant sets a flower…