AUBURN UNIVERSITY, Ala. – Growing pecan trees can be tricky because of the many environmental factors that affect a tree’s health. One of the best ways to promote good health in pecan trees in establishing a proper fertilizing program. Chip East, an Alabama Extension horticulture regional agent, offers the following information about fertilizing pecan trees.
Soil and Leaf Analysis
“It is always important to have a soil analysis done to determine what elements are already present and what other elements are needed,” East said. “A soil test is cheap and easy to do. You can pick up information on soil testing at your local Extension office.”
Chip also said growers can have a leaf analysis done.
“It costs a little more money, but a leaf analysis is a great way to know of any nutrient deficiencies in the tree,” he said. “The process is similar to collecting soil samples, but we take certain leaflet samples from the compound leaf and send to the plant diagnostics lab at Auburn.”
Without doing an analysis on the soil or leaves, there are some general guidelines to follow for fertilizing pecan trees. East recommends applying the following:
- 1 pound of 13-13-13 per tree per year of age up to 25 pounds per tree
- 1 pound of 34-0-0 per tree per year of age up to 20 pounds per tree
- 1/10 pound of zinc sulfate per tree per year of age up to 2 pounds per tree
“Basically, if your trees are more than 25 years old, you need 25 pounds of 13-13-13, 20 pounds of 34-0-0, 2 pounds of zinc per tree each year,” East said. “For large trees, apply all of the fertilizer in April. For younger trees, apply all of the 13-13-13 fertilizer and zinc in April. Apply half the 34-0-0 in April and the remainder in June.”
The optimum pH range for pecan trees is 6.0 to 6.5. A soil test is the best way to know the pH of the soil and how much lime to apply. If lime is needed, 50 pounds of lime per 1000 square feet is equivalent to one ton per acre.
The use of a mechanical spreader may help ensure an even application of the fertilizers. Do not disturb the soil before applying the fertilizer. Spread it under and around the tree in an area twice the branch spread of the tree. The dolomite lime is the cheapest, but pelletized lime is easier to spread.
Alabama Extension regional agents teach pecan classes in different counties and cover topics such as cultivar selection, plant spacing, proper planting and grafting. For additional information on pecans or to attend a pecan class, contact your county Extension office.