April is the time to fertilize your lawn, vegetable gardens, and spring blooming shrubs

(Edited from news article for April 21, 2022)

Like people, plants are influenced by the environment surrounding their roots. As we approach the end of April, now is the time to fertilize your lawn, vegetable gardens, and spring blooming shrubs. This provides nutrients they will need to carry them through the rest of the growing season.

Many people are anxious to fertilize their turfgrass at the first sign of spring. However, applying nitrogen-containing fertilizers too early can encourage weed growth and large patch disease. Fertilization of our warm season turfgrasses in south Louisiana should begin mid-April. Having your soil tested will determine specific adjustments needed for optimal plant growth.

In general, the recommendation is 1 pound of nitrogen per 1000 square feet per year for centipede and carpetgrass. This is applied at ½ pound in April and a ½ pound in June. St. Augustine and zoysiagrass require 1 pound of nitrogen in April and 1 pound in June for a total of 2 pounds of nitrogen. Bermudagrass is the heaviest feeder, requiring 1 pound of actual nitrogen per application in April, June, and August.

If using a complete fertilizer such as 10-10-10, to calculate the amount of fertilizer you need to apply 1 pound of nitrogen, you divide 1 by 10% (concentration of nitrogen in 10-10-10). Therefore, 10 pounds of 10-10-10 is required to supply 1 pound of nitrogen. Be careful overapplying phosphorus to centipedegrass as too much can be harmful.

For many of you, spring vegetable gardening is well underway. It is important make side-dress fertilizer application to many of the vegetable plants during flowering and fruit development. Tomatoes, peppers, eggplants, cucumbers, squash, zucchini, melons, and pumpkins all benefit from applications of calcium nitrate. Applications of 0.4-0.8 cups of calcium nitrate per 10-foot row should be applied at first fruit set for tomatoes, peppers and eggplant or 2-3 weeks after planting for cucumbers, squash, pumpkins, and melons. Repeat this in 3-4 weeks for all plants. Vigorous producers may require a 3rd or 4th application at 3–4-week intervals.

Corn is a heavy feeder. Two side-dress applications are needed. 0.4-0.8 cups of calcium nitrate per 10-foot row is recommended for each application. This should be applied when the corn is about 12 inches tall and again when it is 24 inches tall.

While all the beautiful azalea blooms have faded away, now is the time to fertilize azaleas and other shrubs that have already flowered to provide nutrients for next year’s blooms. A slow-release fertilizer or one formulated for azaleas is recommended at a rate of 1-2 pounds of total nitrogen per 1000 square foot of total bed area. Azaleas, like Camellias, prefer an acidic soil (pH of 5-5.5). If you notice yellow-green leaves it can be an indication the soil pH is too high, or the plant needs iron. Having your soil tested is the best way to know what is needed. Soil testing a service offered by the LSU AgCenter for a small fee.

It is great to be back working in Livingston Parish where my roots run deep. I look forward to working with the people, providing good horticultural advice, and encouraging you all to get out and plant something.

5/2/2022 6:28:51 PM
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