Pecan trees are a valuable resource in Texas, but maximizing production requires a specific and carefully timed fertilization program. The unique climate and prevalence of high-pH or calcareous soils create distinct nutritional challenges. A successful strategy focuses on delivering the correct nutrients at the precise moments the tree needs them for growth and nut production. This tailored approach is essential for a consistent harvest of high-quality pecans.
Primary Nutrient Requirements for Pecan Health
Pecan trees have a high demand for several nutrients, but Nitrogen (N) and Zinc (Zn) are particularly important for Texas growers. Nitrogen is required in large amounts because it drives vegetative growth, leaf production, and the size and quality of the nut crop. A lack of nitrogen causes leaves to appear pale green to yellow, signaling the tree is mobilizing the nutrient from older growth to support new tissue.
Zinc is a micronutrient, needed in small quantities, but it is often the most limiting factor in pecan production, especially in Texas. High-pH and calcareous soils make zinc unavailable for root uptake. Since the tree cannot absorb soil-applied zinc, it must be applied directly to the foliage as a foliar spray. While Phosphorus (P) and Potassium (K) are necessary, they are frequently sufficient in Texas soils, and applications are only recommended if a soil or leaf tissue test indicates a deficit.
Annual Timing Schedule for Bearing Trees
The timing for applying bulk nutrients, primarily Nitrogen, to mature, nut-bearing pecan trees is split into a schedule that aligns with the tree’s annual growth cycle. The goal of this split application is to support both early season vegetative growth and later-season nut development. The first major application of nitrogen should occur in early spring, typically around bud break or when new leaves begin to emerge.
This initial spring application supports the tree as it sets its crop, expands its leaves, and completes most of its shoot growth, which occurs in the first 100 days of the growing season. By mid-summer, the tree will have used much of the available nitrogen to support the developing nuts, which are undergoing a phase of rapid expansion. A second, or split, application of nitrogen is recommended from mid-May to mid-June, coinciding with the start of nut growth.
Applying the nitrogen in two or more smaller doses throughout the growing season, rather than one large dose, maximizes the tree’s uptake and minimizes the risk of nutrient loss through leaching, especially in sandy soils. A third application in early to mid-July may be beneficial to ensure a final dose of nutrition is available for the current year’s growth and to promote proper nut fill. The total annual nitrogen rate depends on the expected crop load, with a general recommendation of about 10 pounds of actual nitrogen for every 100 pounds of anticipated pecans per acre.
Specialized Timing for Zinc and Non-Bearing Trees
Zinc application follows a different schedule than nitrogen because it must be applied directly to the foliage for effective absorption. The timing must coincide with the emergence of new, tender leaf tissue, as zinc is not easily translocated within the tree once the leaves harden. For mature, bearing trees, foliar zinc sprays should begin at bud break and continue in multiple applications to treat each new flush of growth.
A typical schedule for bearing trees involves four to five separate zinc sprays throughout the early growing season, with the first three applications spaced approximately one to two weeks apart, starting at bud break. Subsequent sprays are often timed to coincide with pest control applications, such as the pecan nut casebearer sprays, which occur in late May and late June to early July. These early and frequent applications are necessary to support maximum leaf expansion and shoot growth, which directly correlate with the tree’s ability to produce and fill nuts.
Young, non-bearing trees, which are focused entirely on structural growth, have a distinct fertilization program. Instead of large, split applications, these trees benefit from small, frequent doses of nitrogen throughout the growing season to promote rapid trunk and branch development. For non-bearing trees, foliar zinc sprays should be even more frequent than for mature trees, often recommended every two weeks from April through August, as long as new growth is occurring. This aggressive schedule is designed to maximize the growth rate and bring the tree into production sooner.
Determining Nutrient Needs and Application Methods
Before any fertilizer is applied, a soil test is the necessary first step to accurately determine the existing levels of nutrients like Phosphorus and Potassium, as well as the soil’s pH. Soil testing eliminates the guesswork in fertilization, preventing the waste of resources and avoiding potential harm to the trees from over-application. Texas A&M AgriLife Extension provides soil testing services that give specific recommendations tailored to pecan production in the region.
The application method for fertilizer depends on the nutrient type. Nitrogen, Potassium, and Phosphorus are typically spread granularly over the soil surface beneath the tree canopy. The fertilizer must be broadcast uniformly, extending from near the trunk out to the drip line, but avoiding direct contact with the trunk to prevent damage. Foliar sprays are the most effective method for delivering zinc, as the tree absorbs the nutrient directly through the leaves, bypassing the soil’s ability to render it unavailable. These sprays often include a surfactant to ensure the solution spreads evenly and sticks to the leaf surface for better uptake.