Because the pecan is the state tree of Texas, you should feel encouraged about the ease of culture and the appropriate climate Texas provides for growing pecan trees (Carya illinoiensis). According to Texas A&M Extension horticulturists, pecans can be grown in all counties, but some varieties are better suited to the different regions of the large state. The best time to plant bare root pecan trees is December to March when the soil is still workable, and container-grown trees anytime of year but focus on fall or winter planting. Choosing an appropriate site for growing the pecan is key to enjoying a long-lived and productive nut tree.
Choose a sunny location in a slightly acidic soil that is moist but well-draining. The root systems of these trees is deep, so horticulturists at Aggie Horticulture recommend only planting pecans where the fertile topsoil is at least 3 feet deep.
Buy a healthy, well-structured pecan tree from a reputable nursery. Choose varieties that are known to be well-suited to the Texas summer heat and soils as listed by Texas A&M University's AgriLife Extension publication entitled "Home Fruit Production--Pecans" (see Resources). The best-sized trees for planting and establishing are those that are between 4 and 8 feet in height.
Dig the planting hole 18 to 20 inches deep, advises Charles Rohla, Ph.D., a horticulturist with The Samuel Roberts Noble Foundation. Cultivate it even deeper if your tree's root ball is larger than that. Once the tree is placed in the planting hole, keep in mind the top of the root ball must be at the same level as the hole rim's soil line--never deeper. You may have to re-add soil into the soil's base to plant the pecan tree at the proper depth.
Cut back the above-ground branches of any bare root pecan trees by one-half immediately after planting, advises Texas A&M University. Make the cuts with a hand-held pruners 1/4 inch above a lower dormant bud or branch. This technique allows the tree to better establish the roots over the winter and spring and be well-equipped to grow better once the growing season starts. Do not cut back container-grown pecan trees when planting.
Water the newly planted pecan tree to compact the soil and remove air pockets around the roots in the hole. Add more soil if the planting hole soil level drops after watering. Depending on the size of the root ball, you'll need between 3 and 10 gallons of water to ensure the tree and planting hole are moistened.
Give mature trees 2 inches of water per week, unless provided by natural rainfall. A pecan tree in Texas should not go longer than three weeks without a deep watering, notes Texas A&M University. In the fall and winter, irrigate every six to seven weeks if the soil isn't moist naturally. You need to water pecans in all parts of Texas to grow healthy trees and produce good nut crops.
Fertilize pecan trees with a nitrogen-rich fertilizer product in late March before the leaf buds break dormancy. If there is a good set of young nuts on the tree, fertilize again just after Memorial Day. Apply zinc as a foliar spray to the tree leaves every two weeks from mid-April to August on trees that are less than 7 years old; mature pecan trees need zinc spraying at least three times (every two to three weeks) from mid-April to mid-June, according to Texas A&M horticulturists.
Monitor your pecan tree for diseases and insect pests. Pecan scab is a major problem in all but far western Texas. Other diseases include stem-end blight, shuck dieback, powdery mildew, downy spot and fungal leaf scorch. Insects of concern are pecan nut casebearer, pecan weevil, yellow aphid, black aphid, stink bug and hickory shuckworm. Contact your county cooperative extension office for assistance and guidance in economical and recommended treatments for any of these issues on your pecan trees.