The proper timing of gardening work has a real impact on getting the desired results. One of the challenges of gardening in southeast Louisiana (or anywhere) is learning when activities like planting, pruning or fertilizing are best done.
I’ve recently been getting questions on those three activities. As it turns out, we are at a transitional time in the gardening year when some of these activities need to be done immediately. In other cases, the proper time has come and gone, and it is too late to take action . And for other plants, it’s too early for some of this gardening work to be done. Let me explain.
What to do now
FERTILIZE IF YOU NEED TO: Be careful about fertilizing now. We stop applying fertilizers to most landscape plants and lawns in early September. Here’s why: Typical granular fertilizers we use to fertilize our lawns and landscapes will provide nitrogen for about six to eight weeks. Fertilizer applications made after early September, especially with nitrogen, may keep plants actively growing into early winter.
This increases the possibility of cold damage even to plants that would normally be hardy. This is especially true here, because fall temperatures are generally warm and do not give plants a strong signal to go dormant.
Although somewhat late, you can make a last fertilizer application to your lawn if you do it immediately. But only do this for lawns in poor vigor or where you need to stimulate growth or improve the color.You may make a last fertilizer application to tropical plants such as hibiscus, angel’s trumpet, tibouchina, bougainvillea, cape honeysuckle and night-blooming jasmine. They will continue to grow and bloom until the weather gets cold.
I am not saying that you necessarily need to go out and fertilize plants in your landscape now. If your lawn and other plantings look healthy and have grown well this summer, there is no need.
DO IT NOW: Hedges should be pruned by the end of September.
DREAMSTIME TNS PHOTO < p>
PRUNING: If you need to prune or shear shrubs not grown for their flowers, such as hedges or plantings of ligustrum, holly, boxwood, dwarf yaupon, photinia, viburnum and others, do it now. When you prune or shear these plants, it stimulates a flush of new growth. This growth needs time to mature before winter freezes to avoid damage. Pruning these shrubs in October or November can stimulate late growth that is prone to cold damage from early freezes.
Don’t forget that you need to prune back your repeat-flowering roses in early September. This prepares them for the October to early December bloom period. Do not delay getting this done. Roses may also be fertilized now.Tropical plants that have gotten too large, such as hibiscus, tibouchina, brugmansia and night-blooming jasmine, may be trimmed now. The farther back you cut them, the longer it will take for them to come back into bloom. So, try not to cut back more than about one-third of their height.Tropicals may be pruned anytime during the summer, even when blooming, and it is better to trim lightly occasionally than severely after they get way overgrown. Shoots of cannas and gingers that have already bloomed may be cut to the ground to keep the clumps looking tidy.
TOO LATE: Azaleas have already set their flower buds for next season. If you prune them now, you’ll have fewer flowers later.
LSU AgCENTER PHOTO BY OLIVIA McCLURE
It’s too late now
MORE ON PRUNING: There are plants for which it is too late to prune, however. Fall-, winter- and spring-blooming trees and shrubs have already set their flower buds. Pruning now will reduce or eliminate blooming by removing those buds. This includes shrubs such as sasanqua, camellia, azalea, spirea, quince, Indian hawthorn, gardenia, hydrangea, banana shrub, philadelphus, red buckeye and deutzia, and trees such as Japanese and star magnolia, cherry, redbud, fringe tree, Southern crab apple, mayhaw, parsley haw and silver bell.
That does not mean you are forbidden to prune. It won’t actually hurt the plants. You just must accept the loss of flowers if you do so. If a low branch on a redbud tree is causing a problem, you can remove it now. You will lose the flowers that branch would have produced, but it will not affect the blooming of the rest of the tree. Pruning off a few wild shoots from an azalea will not affect the blooming of the rest of the bush.
SEEDING LAWNS: It’s too late to establish a lawn, such as bermuda or centipede, from seeds. But you have until early October to lay St. Augustine, centipede, bermuda or zoysia sod — but at this point the sooner you do it the better.
TOO EARLY: It’s too soon for planting trees. The optimum time is November-December, so the roots have time to grow and they can sustain the tree in the summer.
PHOTO BY APRIL BUFFINGTON
It’s too early
TREE PLANTING: Our prime planting season for hardy trees, shrubs and ground covers runs from November through March. The high temperatures that are still occurring now mean it is best to wait to plant. It is easier on us and much easier on these plants if we delay planting at least until late October. Fall planting in November and early December is especially advantageous. So, if you are thinking about planting trees, shrubs or ground covers — wait.
COOL-SEASON FLOWERS: Although you may see cool-season bedding plants begin to appear in area nurseries in September, most of these plants would appreciate being planted in October when temperatures are more reliably cooler. Some of the more heat-tolerant cool-season bedding plants that can be planted this month include dianthus, snapdragon, petunia, calendula, dusty miller, gaillardia and alyssum.
Comments are closed.