Daniel Gill, Merrill, Thomas A. | 7/28/2007 2:28:31 AM
By Dan Gill
LSU AgCenter Horticulturist
Flower beds that are past their prime and overrun with weeds can be a common sight in our late-summer landscape. But you don’t have to just give up and accept such sad-looking elements in your landscape, since there are ways you can freshen up these tired beds.
The problems often are the result of our long growing season and abundance of insect and disease problems, as well as the intense heat that makes many of us reluctant to do much work outside.
We know it’s just not reasonable to expect all bedding plants to hold up from the beginning of our summer growing season in early May until its end several months later. Unfortunately, many gardeners give up with the attitude that it is too hot to plant anything now anyway, and they allow their beds to remain unattractive eyesores in the landscape.
I’m here to take away your excuses for those pitiful looking beds, however. Nurseries are still well stocked with colorful, heat-tolerant bedding plants that will grow vigorously from now through late October or early November (when we will plant cool-season bedding plants).
To replant your beds, first remove the old plants and put them in your compost pile. But try to avoid putting any weeds that have set seeds in the compost. Just dig those out and throw them away. You also could spray the weeds with glyphosate (various brands) to kill them before removing them. This would be especially recommended if you are dealing with tough weeds, such as bermudagrass, torpedograss or dollarweed.
Next, spread a 1-inch to 2-inch layer of organic matter, such as compost, bagged or aged manure, landscape soil conditioner, grass clippings or peat moss, over the bed. Sprinkle a light application of any general-purpose fertilizer (following label directions) over the organic matter and then thoroughly incorporate everything into the soil of the bed. Rake it smooth, and the bed is ready to plant.
The heat is no reason not to refurbish your flowerbeds, but you should still be careful when working outside while the temperatures are high. I suggest you try to do this work early in the morning or late in the afternoon – when it is cooler. And be sure to drink plenty of fluids.
When planting late in the growing season, choose well-established plants in 4-inch pots or larger. Make sure the plants you purchase are healthy and vigorous and have been properly cared for. Avoid plants that look wilted or leggy, have poor color or show signs of insect or disease problems. This is not the time of year to nurse struggling plants back to health. Start off with the highest quality plants you can find.
Gardeners often rip or pull apart the roots of root-bound bedding plants slightly when planting them into the ground. This encourages the roots to grow into the surrounding soil and helps the plant get established. But you should do this very carefully or not at all when planting this time of year. Plants’ roots must absorb water rapidly to supply their needs when temperatures are hot, and transplants will not be able to tolerate much damage to their roots now.
Also be careful to plant the bedding plants at the proper depth. The top of the rootball should be level with the soil of the bed. Planting transplants too deep makes them more susceptible to root rot or crown rot. The fungal organisms that cause these diseases are very active in the moist, hot weather we generally see in late summer, so make sure plants are not planted deeper than recommended.
Once planting is finished, mulch with an inch or two of your favorite mulch and water the bed thoroughly. Watering is the trickiest part of planting this time of year. You may need to water the bed fairly frequently until the plants send roots out into the surrounding soil. Watch the plants carefully for wilting, and water when needed.
There are lots of choices for planting now. For sunny beds or containers, choose periwinkle, melampodium, blue daze, purslane, portulaca, pentas, torenia, perennial verbena, salvias, sun-tolerant coleus, lantana, zinnia, marigold, abelmoschus, globe amaranth, cosmos, balsam and celosia. For shady and partly shady beds and containers, choose impatiens, begonias and coleus. I’m sure you are likely to see other great choices available, as well.
If you still intend to add tropical plants to your landscape, do it now so they will have time to get established before fall. Tropicals love the heat and are not stressed out by it like so many other plants. Feel free to plant tropical hibiscus, cannas, gingers, elephant ears and other tropicals in the landscape now.
Depending on where you live in the state, tropical plants may or may not reliably survive the winter. Keep this in mind when deciding how many and where to use them.
On the other hand, if you don’t feel up to replanting flowerbeds at this time, you can still improve the appearance of your landscape.
In that case, remove the old, unattractive plants, control the weeds and then apply a thick (at least 4 inches) layer of mulch over the area. An empty bed that is neat and mulched is far more attractive that one full of weeds and dead flowers. The heavy mulch also will keep the bed weed free and ready for you to prepare it and plant colorful cool-season bedding plants in late October or November.
Get It Growing is a weekly feature on home lawn and garden topics prepared by experts in the LSU AgCenter. For more information on such topics, contact your parish LSU AgCenter Extension office or visit our Web site at www.lsuagcenter.com. A wide range of publications and a variety of other resources are available.