Planting Pecan Trees
To get the best survival, plant freshly dug trees whose roots have been kept moist from digging to planting. If possible, plant trees the day they are received from the nursery. Many trees bought from mail order dealers or garden centers will have been out of the ground for several days. If these trees have been stored and handled properly, they should survive and grow. If your trees appear to have dried, soak them in water for several hours to freshen them prior to planting. Drying before planting and failing to supply adequate moisture for the first two years following transplanting are the major causes of death or very slow growth in young pecan trees. Pecans by nature have long taproots and require a deep planting hole. It’s not uncommon to need a hole at least three feet deep. The hole should be from 12 to 24 inches wide so that all side roots can be properly positioned as the hole is refilled. Never run roots around the hole; instead, prune them at the edge of the hole. Most soils need additional organic matter. Mix peat moss or well-composted organic matter thoroughly with the available topsoil used to fill the hole. Dig the hole deep enough so that the tree can be set at the same depth that it grew in the nursery. Then fill the hole in layers so that lateral roots arising from the taproot can be spread horizontally. Firm the soil in layers as you progressively fill the hole to soil surface level to prevent settling. Do not place fertilizer in the hole. Use the subsoil removed from the hole to build a water-holding basin around the tree. This basin should be 24 to 36 inches across and six to 12 inches deep. Ideally, you want a reservoir that will hold 10 to 15 gallons of water at each watering. Remove one-half of the top of the new tree to balance the top with the root system. This is essential for good survival.
The importance of good soil for pecan production cannot be overemphasized. An understanding of root growth in relation to soil conditions is helpful in selecting the orchard location. Pecan root growth increases sharply in the spring, peaks in late May/early June, and declines gradually until mid-September when it decreases sharply. Root growth continues into the winter months, although at low levels. Due to soil temperature effects, root growth increases with soil depth as the season progresses. Root growth will generally not occur below soil temperatures of 65 degrees F. Pecan root growth is most limited by poor subsoil drainage. As subsoils become waterlogged, root growth is inhibited. In a favorable soil environment, pecan root systems are distributed throughout a large soil volume. Root spread can be twice that of the branches and extend into areas beneath the canopy of adjacent trees. Most pecan roots are concentrated in the top 6 to 18-inch soil layer and are most dense near branch tips. While pecans can be produced over a wide range of soil types and conditions, reports indicate that for best rooting and good production, soils should be deep, fertile, and well-drained, with good water holding capacity. Pecans tend to prefer soils with a sandy loam texture and a clay subsoil. A permeable clay subsoil aids in water holding capacity without water-logging the root zone. Light textured soils with low water holding capacity require adequate irrigation for consistent pecan production. The water table should remain 6 feet below the soil surface for good pecan growth. Shallow water tables limit rooting zones, which limits available water during a prolonged drought.
Pecan trees are most commonly planted as bare root transplants; however, container grown transplants may also be used. Bare root trees provide a lower initial cost and are more readily available. Transplant bare root trees while dormant, from December through March. The earlier they can be planted, the better, in order to get good root establishment by spring. Container grown trees normally suffer less transplant shock and can be transplanted from October-May. Although containerized trees may be planted while in foliage and non-dormant, tree stress is reduced and survival is better when planted in the dormant season. In any case, adequate soil moisture is a necessity.