The concept of growing a tree big enough to provide shade and produce delicious nuts is very appealing to homeowners. However, there are several challenges associated with growing pecan trees in an urban setting.
Because of its tremendous size at maturity, a pecan tree can overwhelm many residential properties. It is also a high-maintenance tree based on the amount of resources required to keep it healthy and ensure a harvest.
The biggest mistake homeowners make is not giving pecan trees enough room. If your goal is to maximize nut production, no object, whether it is another tree or structure, should be located close enough to shade any portion of the pecan tree.
Another benefit of not crowding your pecan tree is a reduction in the incidence of scab, a fungus disease. Air movement through the tree canopy dries the foliage, eliminating the environment for disease development. Boxed-in pecan trees are more prone to scab because air flow is reduced.
Neglected pecan trees can pose a hazard to people and property. Trees that are not properly trained when young have a tendency to develop forked lower branches. With age, these trees are at risk of splitting out during a storm. Winter is the normal time to correct structural defects and remove dead wood; however, pruning can be done at any time, if necessary.
To maintain health and ensure consistent nut production, be sure to fertilize pecan trees annually. Many people fertilize trees based on what they think the tree needs, but fertilizing based on a soil test fertilizer recommendation is much more accurate. For instructions on taking a soil sample, contact your county Extension office or the Noble Research Institute. In the absence of a fertilizer recommendation, apply a complete fertilizer such as 17-17-17 at the rate of 4 cups for each inch of trunk diameter in February. If the tree sets a heavy crop of nuts (noticeable in May), make a second application in June. Broadcast apply the fertilizer starting 3 feet from the trunk and extending a few feet past the canopy. Water the fertilizer into the soil promptly.
Many backyard pecan trees in Oklahoma are deficient in zinc. Trees deficient in zinc have small leaves and highly branched twigs at the shoot tips. To correct zinc deficiency, apply 36 percent zinc sulfate to the soil at the rate of 1/2 pound per inch of trunk diameter with a maximum of 10 lbs. per tree per year. If soil pH is above 7.0 (as indicated by soil test), zinc should be applied as a spray to the foliage. Plan on applying zinc at least three times between bud break and mid June. Apply at the rate of 2 teaspoons per gallon of water.
Don't expect to produce well-filled nuts without irrigation. Because a pecan tree has such an expansive root system, every effort should be made to water the entire surface area covered by the tree canopy. The water needs of a pecan tree will vary from 1 inch per week in the spring to more than 2 inches per week in the summer. If turfgrass is established under the tree, apply additional water to compensate for additional demand. Each watering should be sufficient to thoroughly soak the soil to a depth of 12 inches.
There are several pecan insect pests that routinely damage both foliage and nuts. Aphids feeding on foliage excrete a sticky substance, referred to as honeydew, that falls from the tree like rain, making a mess of everything it falls on, including lawn furniture and vehicles. The "cotton candy" bags that appear in pecan trees during late summer are caused by fall webworm. Webworm infested trees are unsightly and, depending on the timing and severity of the infestation, can experience a reduction in yield. The pecan nut casebearer and pecan weevil are nut feeders. The casebearer destroys small newly formed nutlets in the spring while the weevil attacks the nuts during the late summer and fall. Proper timing of spray applications is especially important for control of the casebearer and weevil. Spray dates for these pests may vary each year, so it's a good idea to check with your county Extension office or the Noble Research Institute for assistance with timing of insecticide applications.
Large pecan trees can be a problem to spray. Hose-end sprayers are the only type most home owners have at their disposal that can spray very far up into the tree, but even these are limited to trees no more than 30 feet tall. If your tree exceeds the reach of your sprayer, enlist the services of a local pest control company.
Spraying a tree located in a residential area can be a risky undertaking. Most people aren't thrilled with the prospect of pesticides drifting over their property. Make every effort to spray on a calm day and use the safest chemical for the job. For assistance choosing an appropriate pesticide, contact your county Extension service or the Noble Research Institute.
No one enjoys fertilizing, watering and spraying their pecan trees only to see squirrels, crows and bluejays carry off the nuts. While it is not possible to achieve complete control of wildlife in urban areas, it is possible to reduce the amount of depredation using live traps and scare tactics.
Residential pecan production is rarely a paying proposition. When you consider the cost associated with animal control, insect control, fertilization and irrigation, most urbanites would be money ahead purchasing pecans.