Heat Gets Crops Popping Our first long hot spell took us beyond the fear of frost. It was time to plant our hot-weather seedlings. Our salad greens are beginning to burst forth. We don’t pull out lettuce heads. Instead, we pinch off outer leaves or give greens a “haircut” from the top to keep them producing. Flowers from out in the “Back 40” beyond the garden fence, where plants are popping, too.