Managing Zinc Deficiency in a Mature Pecan Tree

A centuries-old pecan tree in coastal South Carolina shows classic signs of long-term zinc deficiency: dead limbs, sparse foliage, and poor canopy fill. Despite applications of zinc sulfate, the owner sees no improvement and seeks expert guidance to preserve this historic specimen.

Zinc deficiency in pecans—often called "rosette" or "little leaf"—is common in alkaline or high-pH soils where zinc becomes unavailable to roots. Surface-applied zinc sulfate is often ineffective because it doesn't reach the root zone in sufficient quantities, especially in heavy or calcareous soils. The most reliable approach begins with a soil test to confirm pH and nutrient levels. Based on results, targeted treatments may include:

• Soil-applied chelated zinc (more available in high-pH soils)
• Foliar zinc sprays during spring flush (bypasses soil limitations)
• Trunk injection for immediate uptake in large trees

The South Carolina Forestry Commission employs a forest pathologist, Andy Boone (803-896-8814, Columbia office), who can assess the tree and advise on proper soil sampling and treatment. Given the tree's age and value, professional on-site evaluation is strongly recommended.