The "Caddo" pecan tree (Carya illinoinensis "Caddo") is a hybrid of the pecan tree cultivars "Alley" and "Brooks" that was developed in 1922 or 1923 and released in 1968. "Caddo" is considered a high-yield tree that reliably produces nuts from a young age until maturity. The tree produces football-shaped, medium-size nuts of good quality, though it has only mild resistance to scab disease.
"Caddo" is suitable for U.S. Department of Agriculture plant hardiness zones 6 to 10, where it requires a sunny location. Pecan trees can grow up to 70 feet, with a similar spread, so it is crucial to plant the tree at a safe distance from power lines and buildings. The Clemson Cooperative Extension recommends spacing pecan trees at least 60 to 80 feet away from each other, as crowding will decrease production.
"Caddo" is a protandrous, or Type I, tree. It requires a protogynous, or Type II, tree to pollinate it. Unless there are pecan trees on neighboring properties, it is wise to plant one or two more pecan trees within 200 feet of the tree to ensure nut production. For the home garden, the University of Georgia recommends the Type II cultivars "Elliot," hardy in USDA plant hardiness zones 8 to 10, and "Stuart," hardy for USDA zones 6 to 10.
"Caddo" requires rich, well-draining soil, ideally with a pH between 6.0 and 6.5. Low soil pH can be amended by adding lime. Young trees can benefit from 1 pound of zinc sulfate, applied every spring for the first three years in a circle around the tree that falls just outside of the original planting hole. Larger trees should be given 3 to 5 pounds of zinc sulfate a year. Water "Caddo" generously throughout the growing season and mulch well to retain moisture.
Scab is a fungal disease that commonly affects pecan trees, causing lesions on nuts and leaves that can majorly reduce the yield of the tree. "Caddo" is fairly susceptible to scab and is not considered a scab-resistant cultivar. Though fungicide is an effective treatment for scab, the Clemson Cooperative Extension comments that this may not be feasible management strategy for homeowners. Removing and destroying diseased leaves and nuts in the winter can help prevent the disease from continuing into spring.
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