Home Pecan Tree Fertilization
Homeowner yard pecan trees provide good shade as well as the potential for a valuable nut crop. Pecan trees do require some management you do not have with other yard trees. Fertilization is critical- for the trees to remain healthy and productive; you must establish a good fertilization program.
Nitrogen (N) and zinc (Zn) are the only mineral elements that pecan trees normally need for good growth and production. Nitrogen may be applied on the soil surface, or it can be applied in water through a drip irrigation system. Zinc must be applied as a foliar spray. Zinc applied to the soil is soon tied up in a form unavailable to the tree.
Young Tree - Nitrogen is necessary for rapid tree growth and is the only soilapplied nutrient that most pecan trees ever need. It is important to apply nitrogen in frequent small amounts during the first few years.
Spread fertilizer on the soil surface, under the tree, but well away from the trunk. Nitrogen fertilizers are very soluble and are readily moved into the soil by watering. It is inefficient and unnecessary to make holes around the tree to pour the fertilizer into the ground.
If the trees are not making rapid growth, do not fertilize the first year. Poor growth by a first-year tree usually indicates problems other than lack of nutrition, and fertilizer may hinder rather than help the tree.
Ammonium sulfate (21-0-0) and ammonium nitrate (33-0-0) are common, economical nitrogen fertilizers that can be used. Ammonium nitrate is getting hard to find, so ammonium sulfate may be your only choice. This is fine as it is a slower release product than nitrate. Freeze damage is very common on young pecan trees fertilized after the month of June, so do not fertilize after this date.
Mature Trees - Apply 1 pound (2 cups) of 21-0-0 or 33-0-0 for each inch of trunk diameter in late March before bud break; I know it is now April, but if you missed March do it now. If the tree produces a very heavy nut set in May, make a second application in late May or early June. Apply the fertilizer broadcast on the surface starting 3 to 5 feet from the trunk and extending out a few feet past the tree canopy. Water the fertilizer into the soil promptly. Avoid scattering fertilizer on sidewalks or paved driveways because some materials can cause unsightly, although seldom permanent, spotting.
Zinc is one of the more important nutrients for good pecan growth and production. To be effective, it must be applied to the foliage of the trees- for homeowners this can be a challenge on large trees. However, on young rapidly growing trees it can be done with a hand help pump up sprayer. Frequent zinc sprays are essential for rapid tree growth. Trees deficient in zinc usually have small, weak leaves highly branched (rosetted) twigs at shoot tips and in severe cases, dieback of twigs and branches. During the first 7 years, trees grow best if foliar sprays of zinc are applied at least every 2 weeks throughout the growing season of April through early August. If the trees are not growing, reduce the spray frequency. Spray mature trees with zinc at least three times between bud break in late March or early April and early June. Zinc is needed primarily by young expanding leaflets. Leaflet expansion on mature trees usually stops by mid-June. Two of several choices of zinc materials to spray are: Zinc nitrate (NZN): formulated as a liquid. Use 2 to 4 teaspoons per gallon or 1 to 2 quarts per 100 gallons of water.
Zinc sulfate WP: formulated as a powder. Use 2 teaspoons per gallon or 2 pounds per 100 gallons of water. Zinc sulfate spray can cause leaf burn on other trees in the home landscape especially peaches, plums, and other stone fruits. Zinc sprays are most effective if applied early or late in the day with little or no wind. The higher humidity under these conditions allows longer wetting and more zinc absorption. Zinc sprays pose a minimal hazard to man and animals, yet care should be taken not to contact the spray directly. Zinc sprays are not likely to stain sidewalks, houses, cars, etc.
These zinc materials can be mixed and sprayed in combination with most chemicals labeled for insect and disease control. Consult Texas AgriLife Extension Publication E-145, Homeowner’s Fruit and Nut Spray Guide for recommended combinations. This is an excellent homeowner publication- give us a call at (325)-356 2539 and we can get you one in the mail.