How should I space trees in a new pecan orchard?

Answer: The establishment of a pecan orchard by planting trees in rows is how most new growers enter the pecan industry. Trees can be purchased with the cultivar already budded to the top, or planted as a seedling and grafted in the field. (To be “true to name,” a cultivar must be propagated asexually, i.e., by budding or grafting rather than propagation by seed). The spacing of pecan trees depends on geographical location. In their native and eastern ranges, pecan trees are commonly spaced on a 40 feet x 40 feet grid pattern, which is the equivalent of 27 trees per acre. After about 16.22 years, trees are thinned by half on a diagonal, thus leaving 14 trees per acre. At about 25.35 years old, the third and final thinning will leave a spacing of 80 feet x 80 feet with seven trees per acre. For a long time, the pecan industry was based on a 35 feet x 35 feet tree spacing. However, recent economic analysis showed an initial 40 feet x 40 feet planting pattern is more profitable because the wider spacing allows the temporary trees more time to produce nuts before they are removed. In the western range, where sunlight is more intense, trees are planted at 30 feet x 30 feet, the equivalent of 48 trees per acre. Ultra-high density western pecan orchards, spaced at 15 feet x 30 feet, are typically managed by mechanical hedging. Establishing a Pecan Orchard, a fact sheet by Oklahoma State University Extensio, provides illustrations and details for pecan orchard layout and thinning operations. For more information on growing pecans, consult the ATTRA publication Sustainable Pecan Production. This publication briefly introduces essential knowledge on the basics of pecan culture such as geography, native versus plantation systems, and economics. This is followed by notes on pecan farming techniques that emphasize sustainable and organic production methods: non-chemical weed control; orchard floor vegetation management using legumes; pecan nutrition with emphasis on organic fertilizer options; and recommendations for organic and least-toxic control of pecan insects and diseases. A selection of pecan literature and online resources available from the Extension Service and horticultural industry are provided as further sources of information.