March Gardening Madness

February 26, 2008
March 29 Frank Davis Book Signing (Thibodaux)
February 29, 2008

The warmer weather trends of March make most gardeners ready to work outside. First, let’s take a brief look at landscape gardening, then vegetable gardening. You should try to finish your shrub and tree planting during March so the plants can become well established before the summer heat moves in. Remember, don’t buy and set out more plants than you have time to care for — they will suffer for it during the summer. Remember, too, proper planting and bed preparation are critical.

If you didn’t get around to pruning your spring flowering and evergreen shrubs during February, do it NOW. However, be sure to prune spring flowering shrubs after they have bloomed. These include spiraea, azalea, camellia, forsythia, jasmine, mock orange and flowering quince.

Now is the ideal time to fertilize landscape plants because you give them food just before the spring growing season begins. Buy your fertilizers on the basis of what your plants need, not on the basis of pressure claims, advertising or the color of the product. Slow release fertilizers are best. Always read and follow label directions.

If you have roses, you’ll need to start a regular spray program as soon as the plants begin to produce leaves. If you allow black spot disease to set in, you’ll find it quite difficult to control. You can help prevent disease problems by keeping a fungicide on the foliage at all times.

Effective fungicides (products that control diseases) are sold under various brand names. Look for brands that contain chlorothalonil, captan, fixed coppers, mancozeb, maneb or triforine. Alternate these chemicals every week or week and a half. ALWAYS READ AND FOLLOW LABEL DIRECTIONS.

Now let’s look at vegetable gardening. All through March you can plant snap beans, Swiss chard, collards and sweet corn. Also throughout the month, you can transplant tomatoes, peppers and eggplant. Later this month you can plant cucumbers, Lima or butter beans, cantaloupe, okra, southern peas, pumpkin, squash, peanuts and watermelon.

When you go to the nursery or garden center to buy your tomato plants, you’ll want to buy those varieties recommended for Louisiana. They are Celebrity, Champion, Monte Carlo, Creole, Pelican, Jet Star, Better Boy, Fantastic, Terrific and Floramerica. Newer hybrids are Merced, Mountain Delight, Mountain Pride and Empire. For tomato spotted wilt resistant varieties, check out Amelia, BHN 444, and Bella Rosa. Try Pink Girl for a pink fruit type. Good canning varieties are Royal, Chico, Whirlaway and Roma.

Lawn Care

Many readers and others have been mowing the lawn or getting the spring garden ready for planting. REMEMBER that it is too soon to fertilize your lawn. Do not fertilize your lawn until the first week of April. Soil pH is the key for fertilization success. Have your soil tested and keep the soil test results to refer to in case of problems or questions about the lawn-grass. By following the recommendations of application rates of nutrients, your lawn can be brought into balance. Call me at 446-1316 to find out how to get your soil tested.

Chemical fertilizers are available in granular, pelleted and liquid or water-soluble forms. The label on fertilizer containers will list a chemical analysis in the form of 3 numbers separated by hyphens. These numbers represent the percentage by weight of nitrogen-phosphate-potash in this order. Research shows a 3:1:2 (18-6-12) or a 4:1:2 (24-6-12) ratio fertilizer superior for lawn turf grasses. These can be more difficult to find than the regular complete and balanced fertilizers. Balanced fertilizers like 8-8-8 and 13-13-13 should be avoided due to their fast release of nitrogen.

Check with your local garden center or feed store to see what type(s) of fertilizers are available for your lawn. A slow-release type fertilizer is better because it does not release the nitrogen quickly and it stays around longer so you may not have to re-apply later. This saves your time and reduces non-point source pollution by preventing nitrogen runoff into waterways and bayous.

It is very important to determine if your fertilizer contains fast- or slow-release nitrogen. High amounts of fast-release nitrogen may burn the grass, cause excessive growth or build up thatch and lead to a “weak” lawn, which is susceptible to insect or disease damage. Slow-release fertilizer costs more, but can be applied at higher rates less often than fast-release fertilizer, so it may actually be cheaper.

The granular or pelleted form of fertilizer is the most common. It should be applied with a broadcast or drop-type spreader. When using spreaders, care should be taken to avoid excessive overlaps or areas of missed coverage. Measure the yard and calculate the amount of fertilizer needed. Check the calibration of the spreader. If there is any question, it is always better to under-apply than to over-apply fertilizer.

The liquid or water-soluble fertilizers are more expensive and need to be reapplied often. Justification of their cost is questionable when compared against slow-release, granulated turf fertilizers. Only part of the phosphorous is water soluble, meaning some is unavailable to the plant. Also, water-soluble fertilizers are more difficult to evenly apply. Uneven applications result in a lawn with inconsistent “waves” of green.

Always irrigate after fertilizer applications to minimize chemical “burning” of the lawn.

For most warm season lawn grasses, there is little or no root system present prior to early April. Application of a fertilizer before this time will not be beneficial. Rather, it will encourage weed growth and promote disease development. This is very critical since we had a very high incidence of brown patch disease in many lawns this past year. Early and too much nitrogen can enhance disease conditions so avoid nitrogen fertilization on these lawns in the spring. For unaffected lawns, the following are suggested fertilizer application dates for our area. Keep in mind that environmental conditions may alter these dates.

St. Augustine — April 7 and June 1

Centipede* — April 7 and June 1


Hybrid — April 7, June 1 and July 15

Common — April 7, June 1 and July 15

*For centipede, use half the application rate for each application date. This means only 1/2 pound of nitrogen will be applied at one time.

Weed and Feed fertilizers have become very popular. One drawback to this type of fertilizer is that feed application dates do not always coincide with weed preventative application dates. To be effective, weed preventatives are usually applied at a date, which is too early to fertilize.

Question of the Week: What percentage of initial citrus blooms is needed to have a productive yield?

Answer: Research has indicated that 3-5% of the initial bloom of citrus needs to be properly pollinated and set for an average yield.

Terrebonne Parish 4-H Centennial Reunion:

Are you a former 4-H Alumnus? If so, the Terrebonne Parish 4-H would like to invite you to the 2008 Centennial 4-H Reunion. If you are interested in attending this program on Wednesday, May 7th, 2008 and learning more about the current 4-H program and seeing other 4-H alumni, contact the 4-H office at (985) 873-6495 or e-mail or to add your name to the invitation list. Help us spread the word and make this a very good reunion.

For more information on these as well as other horticultural topics, call me at 985-446-1316 or email me at You can also check out the LSU AgCenter website at