What common ornamental trees are particularly susceptible?
• Iron: pin oak and sweetgum. • Manganese: white oak, white pine, and red maple. • A number of other common species (such as grey birch or hackberry) show reduced vigor and health, but survive better. How can I solve the problem? • Do not plant susceptible species on soils with a high pH. • Improve the drainage. In many cases, significant improvement can be made by simply reducing soil saturation. • Acidify the soil. Place small amounts of an appropriate compound in 1-2″ holes drilled 2′ apart and 12-18″ deep in a band around the dripline. Best results have often come with a mix of a fast acidifier, a slow acidifier, and organic matter. Repeat as necessary. • Apply a chelate as a soil drench if one micronutrient is involved. The best iron chelate on a high lime soil is EDDHA, found in several commercial products. Repeat as necessary. • Tree injection works well, but requires multiple and repeated wounding. Spraying is ineffective, because crown coverage is difficult and marginal leaf s
