Silas Cecil | 8/17/2012 6:08:37 PM
August 16, 2012
Shrub, Lawn and Ground Cover Fall Maintenance
You might not think that fall is upon us with the summer heat, yet take a moment and evaluate your landscape. With every landscape, large or small, comes with what I like to call sweat equity and of course, management.
Now is also the time to finish up pruning many shrubs and trim some bedding plants. But it’s time to stop pruning spring-flowering trees and shrubs. Be mindful when pruning if the plant has already set their flower buds for next year. Extensively pruning or cutting back these plants from now until they bloom will generally diminish or eliminate the plant’s flower display. It is all right to selectively remove specific shoots or branches to shape these plants without affecting the flowering of the remaining growth. Just don’t get carried away
This month is the latest we should fertilize hardy shrubs and ground covers in the landscape. You may fertilize your shrubs and ground cover that are actively growing to encourage one last burst of growth; however this should be accomplished before late August. Shrubs and ground covers may be fertilized by sprinkling a granular fertilizer in the bed where they are growing. With shrubs, you also may apply the fertilizer around the drip line of each plant and lightly incorporate into soil. Rates are generally higher for larger shrubs, but check package recommendations for specific amounts. You can use granular, general-purpose fertilizers for most fertilizing jobs in the landscape. These fertilizers are relatively inexpensive and easy to use. They provide an immediate release of nutrients and then continue to feed for about six to eight weeks thereafter.
With all these instructions in mind, you don’t necessarily need to go out and fertilize now. If your shrubs and ground covers look healthy and have grown well this summer, there is little indication fertilizer is needed. However, if they have performed poorly, have shown little vigor or you have been meaning to fertilize, now is the time to do it. Not later.
Fertilizer applications made later, especially those with nitrogen, may keep plant actively growing into early winter which increases the possibility of cold damage even to plants that normally would be winter hardy. This holds true for us in Louisiana since fall temperatures generally are mild and do not give plants a strong signal to go dormant.
The same is true for lawns. Louisiana usually stays warm well into the fall and lawns continue to grow until nighttime temperatures dip into the 50s. More than likely it is time to hang up your fertilizer spreader. Fertilizing warm-season grasses during the fall with high nitrogen (summer-type) fertilizers, winterizing fertilizers or weed and feeds containing nitrogen are not recommended.
Given a slight warm spell during winter months coupled with nitrogen fertilizer may lead to your lawn breaking dormancy and risk freeze damage after an unexpected warm spell. In addition, stimulating fall growth of St. Augustine grass, centipede grass and zoysia with nitrogen leads to increase brown patch disease and winter kill.
The only fertilizer that should be applied in the fall in South Louisiana is muriate of potash. Muriate of potash (0-0-60) is the true winterizing fertilizer and it may be applied in September or October to provide increased disease resistance and cold tolerance. Since there is no advantage to applying excessive amounts of potash, get a soil test before applying potash to your soil. Be sure to mow and water your lawn as needed to keep it healthy.
For more information contact your local Cooperative Extension Service at (318) 964-2249 or visit our website www.lsuagcenter.com . It is the policy of the Louisiana Cooperative Extension Service that no person shall be subjected to discrimination on the ground of race, color, national origin, gender, religion, age or disability.