Since the heat is setting in, try to get any pruning chores that are needing done as soon as possible. Once it begins to get hot and dry, plants start slowing down on their growth. We want them to rebound so they can set new flower buds for next year.
Big leaf hydrangeas, oak leaf hydrangeas, and gardenias will begin to bloom if they have not been winter damaged. These are three plants that bloom in the summer but set flower buds in the fall. If you grow any of these three plants and they need pruning, make sure it gets done as soon as the flowers fade. The single-flowered gardenias (Daisy and Kleim’s Hardy) tend to bloom all at once and are done quickly. They can be pruned as needed once all the flowers are gone. Many newer gardenias do re-bloom later in the season, so later blooms may be delayed or non-existent, depending on how much pruning is done. For big leaf hydrangeas and oak leaf hydrangeas that need to be pruned, remove older, thicker canes at the soil line after the blooms have faded.
By now, most cool season vegetables are likely beginning to bolt or stop producing as the heat increases (“bolting” is the term used for the flower stalk that appears on lettuce, greens, and onions). As cool season vegetables play out, replant with warm-season crops. Now is a great time to begin planting winter squash, pumpkins and gourds, okra, and southern peas. You can also still plant tomatoes, peppers, eggplants and watermelons.
Pay attention to your gardens and watch for insects and diseases. If you find something you are unsure of, take a good picture and send it to your county agent, or take a sample in. Early detection coupled with proper identification of a problem can led to a fast solution.
Fertilize your tomato plants lightly about every two weeks once they start setting fruit, and make sure you water them evenly. Fluctuations in moisture can lead to issues, including blossom end rot. We typically get our first calls about blossom end rot when we have a dry spell followed by a heavy downpour. Blossom end rot starts as a water-soaked spot on the bottom of the tomato, which quickly turns black. Most gardeners think they have a disease, but it is a physiological problem—a calcium deficiency typically caused by fluctuations in moisture levels. Mulch your plants and try to keep the moisture levels even.
Perennial plants are those that come back for at least two seasons. Right now, many are in full bloom, including purple coneflower, daylilies, gaillardia, hardy hibiscus, and lilies. One that continues to gain in popularity is the milkweed. The showiest of them is the bright orange butterfly weed, but all members of the Asclepias genus are great host plants for the monarch butterfly. As the flowers end on many perennials, they begin to form a seed pod. But, allowing them to set seed delays more flowers. Deadheading (or removing the spent flowers) will direct energy back into flower production much quicker. Know the fertilizer needs of your perennials. Some like fertility such as hosta, while others require very little, such as Artemisia and lambs ear.
Annual and tropical color choices abound at local nurseries and garden centers. No garden should be without color, so if yours is, start planting. Most annual and tropical flowers like fertility. Frequent watering also leaches out nutrition, so fertilize every two to three weeks to keep them flowering. As with vegetables and shrubs, watch your flowers weekly to scout for insects or diseases.