Northern & Central Midwest
Let Lettuce go to Seed
Let lettuce and greens go to seed. Leaving the flower stalks on will draw beneficial wasps into the garden to help you out. Also, as the flowers produce and scatter seeds, the plants will sow your fall crop of greens without having to lift a finger.
Stop Harvesting Rhubarb and Asparagus
Stop harvesting rhubarb and asparagus. Allow asparagus stalks to feather into their lovely foliage, which will allow the plant to begin to produce sugars for winter storage and a tasty crop next spring. Rhubarb should be left alone also to replenish the crop for next year. Rhubarb can sometimes be harvested minimally again in the fall.
Pick Beans Daily
Pick pole and bush beans daily. Don't let the pods get larger around than your little finger or the plant will move into a slowdown phase. Once the plant begins to develop seeds, it has finished its life cycle and will stop producing. Besides, the beans are at their most tender before they produce seeds.
Catch Mildew Early
Watch for mildew on phlox, zinnias and bee balm. At the first sign, spray with a mixture of one tablespoon baking soda and one teaspoon dish detergent or insectidical soap in a gallon of water. Spray every four or five days to control mildew. This also works on roses.
Deadhead perennials as needed to keep them blooming as long as possible. Many will rebloom if deadheaded regularly. Some perennials such as coreopsis and geraniums benefit from a shearing back once the spring flush is finished. Use hedge shears and cut plants back by half. They will make attractive new foliage with sporadic blossoms the rest of the summer.