(08/06/2021) The heat is turned up and the rain is unrelenting. What can you do this month in the garden? As we look forward to cooler fall weather there are things to do to prepare for the fall and still time to tackle summertime gardening tasks.
Prune your blooming roses back about one-third of their height in late August to early September to encourage new blooms for October and November. Remove all the dead canes and diseased wood.
If the plants are showing signs of black spot or mildew, be sure to rinse your pruners in 10% bleach solution then in water before moving onto healthy shrubs to prevent the spreading of any disease. Fertilize with an all-purpose fertilizer or one designed specifically for roses after pruning at recommended rates to encourage new growth and to improve flowering for the fall bloom.
This is also a good time to spray roses for blackspot, powdery mildew and other fungal diseases. You may choose to use triforine, thiophanate methyl, or copper oleate. Follow manufacturer’s directions carefully. Rake up and remove all fallen leaves to prevent further infection of rose bushes and dispose of them in the trash.
Ornamental bedding plants have either grown out of control with the warm and wet weather or they have just tuckered themselves out in all the heat. Trim or stake tall plants and deadhead spent flowers on annuals and perennials to give them a boost.
Consider another application of fertilizer for your lawn. Your third and final application of fertilizer can be made in August for Bermudagrass, St. Augustine grass and Zoysia grass. Centipede it is not necessary.
Chinch bugs, sod webworms and armyworms may be causing damage in your lawn. All three feed on grass stems and stolons. Look for brown patches in the lawn and signs of caterpillars or adult moths. If the problem has gotten out of control, consider insecticide applications of bifenthrin, carbaryl or permethrin. Follow the label instructions carefully.
Another thing you can do this month is dig up and divide perennial flowering plants such as daylilies and irises. In general, most prolific perennial plants such as lilies, irises and ornamental grasses need to be divided over time. When you notice plants beginning to decline or they cease to make flowers, it is typically an indication of overcrowding.
Plants that are overcrowded begin to decline in vigor and health due to increased competition for sunlight, nutrients and water. This will be most noticeable when plants start to look a bit ragged.
Signs usually manifest when clumps begin to decline and die out in the center of the plant, and they may stop flower production all together. When you begin to notice this decline, it’s time to start dividing the plants to help decrease competition for nutrients and water.
Divide plants first thing in the morning or late evening when the temperatures are not too hot. When dividing plants, use a spade or shovel to carefully lift the clump of plants from out of the ground and avoid damaging roots as much as possible. When you have a good clump out of the ground, use a garden knife or spade to cut clumps into smaller pieces for moving.
Transplant to a new container or in another portion of the lawn or share them with friends or family. Be sure to water plants as well to avoid added stress. Continue to watch plants over the next few weeks to ensure adequate water as they establish new root systems.
Dividing and replanting during the late summer and early fall allows plants to establish a good root system before going into dormancy during cooler winter months.
Overall, perennials are best divided in the very early spring when they are just breaking dormancy or in the late summer after they have stopped flowering and begin looking a bit ragged. Avoid disturbing perennials when they are forming flower buds or are in bloom.
It’s time to start planning your fall vegetable garden. Transplant fall tomato plants into your garden by mid-August for North Louisiana and the first week of September for South Louisiana. Some suggested cultivars for fall production are Florida 91, Phoenix, Sun Leaper, Solar Set, Sunmaster and Talladega. Fall seeds of broccoli, Brussel sprouts, cabbage, cauliflower, collard greens, cucumber, kale, lettuces, lima beans, Swiss chard, Southern peas, shallots, squashes and turnips can be planted later this month.
Perform maintenance in the summer vegetable garden. Remove spent summer tomatoes, peppers, eggplants, etc. that have tuckered out. If your spring-planted eggplant, pepper plants and okra still look good let them continue to grow. They often produce another fall crop.
Divide overcrowded irises in late summer. Photo by Heather Kirk-Ballard/LSU AgCenter
Sod webworm damage appears as yellowing to brown patches in the lawn. Photo by Heather Kirk-Ballard/LSU AgCenter
Transplant fall tomato plants into your garden by mid-August for North Louisiana and the first week of September for South Louisiana. Photo by Heather Kirk-Ballard/LSU AgCenter
If the plants are showing signs of black spot or mildew, be sure to rinse your pruners in 10% bleach solution then in water before moving onto healthy shrubs to prevent the spreading of any disease. Photo by Heather Kirk-Ballard/LSU AgCenter