By Sharon Omahen
University of Georgia
If your backyard pecan trees supply the nuts for your seasonal pecan pies, University of Georgia experts say it's time to fertilize them for next season.
Fertilize home-landscape pecan trees at least once a year, preferably in February, said Wade Hutcheson, the UGA Cooperative Extension Coordinator in Spalding County, Ga.
Use this formula
"Pecan trees are rather heavy feeders and need 4 pounds (of fertilizer) per inch of trunk diameter," he said. "So if the tree's trunk is 10 inches, apply 40 pounds of fertilizer."
Hutcheson recommends homeowners use a "triple 10" fertilizer followed by 3 to 5 pounds of zinc phosphate. "If you buy a pecan tree special fertilizer you can eliminate one of these tasks, because it's already blended with zinc," he said.
Fertilize backyard pecan trees in June and September, too.
Besides adequate fertilization, Hutcheson says backyard pecan trees need proper sanitation. "This means, simply, keep the floor area around the tree clean of limbs, old nuts and leaves," he said. "This debris provides a home for pests, and you definitely don't want pests."
Weevils, wasps and scab
Backyard pecan pests include pecan weevils, pecan scab and pecan phylloxera. Pecan weevils are the tiny carpenters that bore the pin-sized hole often seen on nuts from homegrown trees.
"Pecan phylloxera is a small, wasp-like insect that stings the leaves of pecan trees," Hutcheson said. "Inside the leaf, the female lays an egg that forms a gall on the leaf. It looks like a bump on the leaf and cuts down on production."
Pecan scab is a disease that is best prevented by planting resistant varieties like Curtis or Elliot. “Pruning any limbs touching the ground improves air movement through the tree’s canopy,” he said. “This also reduces the leaf wetness necessary for disease development.”
When backyard pecan growers in Spalding County see the bumps on their pecan leaves, they call Hutcheson to ask why their tree looks like it has the measles.
Homeowners can't afford fight
"If your home pecan trees are infected by insects or diseases, it's impossible and impractical to try to treat for them," he said. "Commercial growers use specialized, expensive pieces of equipment pulled by enclosed cab tractors to spray pesticides into the canopies of their trees. As a homeowner, you can't do this. And quite frankly, your neighbors wouldn't be too happy with you if you did."
Unless your backyard tree has sentimental value, Hutcheson says it's much easier and less expensive to buy pecans from the supermarket.
"Backyard pecan trees are leaf-bearing monsters," he said. "Every other year you may get some nuts, and then you have to pick them up, crack and shell them. If the tree's already in the landscape or you helped your granddaddy plant it, fine. Otherwise, it's a lot easier to buy shelled nuts and support our state's commercial growers."
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)