Proper fertilization is an important culture practice for proper growth and nut production. Annual fertilization, during the month of February is the most practical and effective tool available to the homeowner for improving pecan production. Fertilizers, however, cannot compensate for poor conditions such as lack of moisture, inadequate disease or insect control, undesirable soil and sites or poor varieties. Standard fertilization of lawns near and beneath pecan trees may supply much of the fertilization requirements of both trees and lawn. An additional fertilizer application may be needed to supply fertilizer requirements especially in years with large nut crops.

Fertilizer should be applied by broadcasting over the root zone of the pecan tree. Fertilizing trees by placing fertilizer in holes beneath trees give little additional benefit. Exercise care when applying fertilizer. Excess fertilizer in narrow bands or clumps could injure lawn grasses or tree roots. Uneven application can also cause dark and light green streaks in the lawn.

The fertility needs of pecan trees can vary. Young pecan trees transplanted in deep, loamy, fertile soil may not need fertilizer additions immediately. But trees transplanted in nonfertile, poorer soils may require several applications of fertilizer beginning in June the year of transplanting. Do not place fertilizer within 1 foot of tree trunks.

Guidelines for fertilizing pecan trees based on trunk diameter – Apply 3 lb of a complete fertilizer (8-8-8) or an equivalent amount of another complete fertilizer per inch of trunk diameter measured at about 1 foot above the soil line in February or early March. Later during the growing season (May or early June); add an additional 2 lb of (8-8-8) per inch of trunk diameter on trees that have a large nut crop. Example: A tree 10 inches in diameter should receive 30 lb of 8-8-8 or 18.5 lb of 13-13-13 when applying 3 lb of fertilizer per inch of trunk diameter.

When zinc deficiencies occur on acid soils, apply 36% zinc sulfate to the soil at a rate of 1/2 lb per inch of trunk diameter up to a maximum of 10 lb per mature tree every third year. On alkaline soil with a pH of 7.0 and up, zinc must be sprayed on the leaves at 14-day intervals April through June. Use 2 to 3 lb per 100 gallons of water or 2 to 3 teaspoons per gallon of water. Three sprays should be sufficient on older trees, 3 to 5 on younger trees.

Rose Pest Problems
Get roses that are highly susceptible to black spots (such as many hybrid teas, grandifloras, floribundas) off to a great start by starting a regular spray program by March for black spot control. You cannot wait to see the symptoms of this potentially destructive disease to control it. Only a regular, preventive program of spraying will do the job. Black spot is the most common disease of roses in Louisiana and causes nearly circular black spots with frayed or fringed margins. Infected leaves turn yellow and fall off, leaving the bush denuded of foliage and weakened. Weekly applications should be made from March through November for best control.

If this seems too much trouble, get rid of cultivars that have constant problems with black spot, and choose those that have more natural resistance to the disease. Products for controlling black spot (and other rose diseases) include captan, mancozeb (Manzate), triforine (Funginex), chlorothalonil (Daconil), thiophanate methyl (Fertilome Halt) and thiophanate methyl plus mancozeb.

A few insects cause problems in spring, most notably aphids and thrips. Aphids cluster on the buds and new growth, sucking out the sap of the plant. This infestation can cause buds to abort and new growth to be distorted or deformed. Aphids are easily controlled with any common insecticide labeled for use on roses. Spray as needed since the insects often return when the original population is killed off (do not spray if natural predators, such as ladybugs, are present and controlling the population). Thrips are tiny insects that bore into the flower buds and feed on the petals. Infested flowers will not open properly, or they will open but have brown or tan edges to the petals. It's heartbreaking to see your spring and early summer flowers ruined. Systemic insecticides, such as acephate (Orthene, Isotox) or imidacloprid will prevent this problem. Question of the week: My lawn is starting to show signs of growth, when should I fertilize? Answer: Many lawns are coming out of dormancy and have started to green up and start growing. They are in a transitional period and should NOT be fertilized until early April. If you fertilize now, you will increase lush growth and increase disease pressure and the possibility of predisposing your lawn to cold damage if we get a late frost or freeze.