Turfgrass fertilization time? Not necessarily

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By Staff Brunswick Beacon

The Master Gardener info line is receiving calls concerning lawn fertilization and weed and feed.

March is not the time to fertilize turfgrass varieties grown here. March is usually the time your local garden centers begin major advertising campaigns to sell lawn fertilizers. For the types of grasses grown in this area, make sure it’s the right time to feed your lawn. In general, the best time to fertilize a lawn here is when it is actively growing. That is usually May at the earliest.

Fescue should be fed in the fall

Most lawns, including bermudagrass, zoysia, centipede and St Augustine grasses that go dormant in winter, should not be fertilized until late spring through mid-fall (May to early September).

Fertilizing now would be a waste of time and money. Why shouldn’t you fertilize warm-season grasses when they are dormant? First, when grasses are dormant, their roots are not able to absorb or use the nutrients from fertilizers. By the time the grass does begin actively growing, most of the nitrogen you applied will have been lost from the soil. Each of the warm season grasses has different amounts and time requirement. Contact the Extension office for more information.

Don’t feed the weeds

Also, fertilizing while the grass is dormant actually encourages more winter weeds, because you are fertilizing the weeds instead of the lawn. Without competition from the lawn, these weeds will grow faster and become more prolific as a result of dormant fertilizer applications.

Lastly, fertilizing lawns during their transition into dormancy in the fall or out of dormancy in the spring may encourage lawn growth that is more likely to be injured from winter kill or a sudden cold snap. Bare spots and thinning of the lawn, as well as delay in spring green-up, may occur when lawns are forced to grow when they should be dormant.

Combo products not the answer

So, should you apply convenient weed and feed products that combine a pre-emergent herbicide and fertilizer in one application? Unfortunately, the ideal time to apply a pre-emergent herbicide actually contradicts the ideal time to apply fertilizer for warm-season lawns. These products are intended for fescue and other cool-season grasses.

For bermudagrass and other warm-season grasses, buy fertilizer that is separate from herbicides. Apply each at its recommended times following label directions.

Start with a soil test

A soil test is always a good starting point before investing in fertilizer or lime. Your local N.C State University County Extension office can provide testing for your soil and provide an exact pH and nutrient analysis with recommendations on how much fertilizer and lime, if any, to apply, if any is needed. Contact your local Extension office by calling 253-2610.

Send your gardening questions or comments to: Brunswick County Master Gardener Column, P.O. Box 109, Bolivia, NC 28422, or call 253-2610. Enclose a self-addressed stamped envelope if requesting information or a reply. Answers may be printed in this column.