When to Trim Pecan Trees?

Pecans are grown for their flavorful nuts.

Pecans bring to mind that Southern delicacy, pecan pie. North American natives that originally grew in the southeast, pecans do best with extended warm growing seasons. They are grown today in zones 6 through 9 not only for their flavorful nuts, but as landscape trees. Pecans become large shade trees (up to 75 feet high and wide) and two types are needed for proper cross-pollination if you want fruit. Early trimming and training help produce a manageable mature tree.

Why Trim

Trimming young pecans during the first five years of growth gives your mature trees good branch structure. It produces an open, wind-resistant tree that can be kept to a moderate size. Trimming lets you select the best side branches to develop. Removing weak growth and limbs with narrow crotches prevents broken branches later. Good trimming forms a spiral branch arrangement that's better for the tree and easier to harvest. Once your tree is grown and shaped, annual trimming will rarely be needed. Too severe a trimming causes pecans to stop fruit production.

Early Trimming

The objective when trimming young pecans is to form a strong scaffolding of branches to support nut production. Young pecans are most commonly trained to a central leader by heading back the young whip (unbranched 1-year-old tree) with one trim cut. Using branch selection, spiral spacing and tip trimming in the first five years to shape your new pecan trees is crucial. Younger trees are best pruned in very early spring before new growth breaks since dormant pruning can cause winter injury.

Yearly Trimming

Yearly trimming can be done during dormancy or during summer. During fall as the pecan begins to lose its leaves, it stores up energy to support itself the following spring. Trimming done after the pecan has put aside these reserves will make it put out lots of unwanted new shoots in spring. Dormant trimming causes extra vegetative growth because you remove existing leaf and branch structure when the pecan has plenty of energy reserves. There's not as much canopy to support so the pecan grows wildly. Heavy trimming during the dormant period uses the energy your pecan would otherwise put into fruit growth. It becomes a vicious circle of removing too much vigorous growth, only to see the same pattern repeated yearly. If you need to thin unwanted shoots, trim in summer. Summer trimming reduces your pecan's growth by removing parts of the tree that provide energy. It reduces shoot production rather than encouraging it like dormant pruning.

Ongoing Maintenance

Mature pecan trees are not often pruned except in commercial orchards when nut production slows. They do benefit from having some trimming done to open up their canopies to allow light and air to penetrate. Crossing branches and water sprouts will have to be trimmed out. The traditional time for mature tree trimming is late winter while trees are still dormant.

References

• University of Arkansas Division of Agriculture: Pecan Trees
• North Carolina Cooperative Extension Service: Training & Pruning Fruit Trees
• University of Arkansas Division of Agriculture: Pecan Production in the Home Garden
• New Mexico State University; Training Young Pecan Trees; Esteban Herrera
• University of Florida IFAS Extension; The Pecan Tree, Tree Training and Pruning; P.C. Andersen and T. E. Crocker
• New Mexico State University; Pruning Mature Pecan Trees; John M. White, Sammy G. Helmers and Esteban Herrera

Resources

• Texas A&M AgriLife Extension; Home Fruit Production -- Pecans; John A. Lipe, et al.
• Oklahoma State University; Training Young Shade and Ornamental Trees; David Hillock, et al.