Post Oak Preservation
Rapid Decline of Post Oaks
Post Oaks throughout the region are rapidly declining. We specialize in evaluating and treating stressed post oaks.
Cause:
The primary reason for the decline is a root rot, which typically has two primary causes. The first is wet soil due to increased rainfall, irrigation, or poor drainage. The second is a fungus called Phytophthora, which feeds on the tree's microscopic feeder root system. Additionally, we believe the increased rains have caused micronutrients to wash out of the soil. This reduces the amount of nutrition available to already stressed trees.
Symptoms:
Symptomatic post oaks are typically sparse, with a significant amount of sky that can be seen through the canopy. Stressed trees can have an off-color look, which can be light green, yellow, or brown. Dieback at the tips of branches is often seen in trees under stress. Post oaks can decline slowly over several years or rapidly during hot weather. This decline is especially likely in trees with other conditions that affect the root system such as trenching, soil compaction, and drainage issues.
Treatment:
The treatment program we use addresses two key issues: 1.) reducing the impact of the root rot fungus 2.) developingng the tree's feeder root system and the surrounding soil quality. Initially, we use a combination of two treatments. The first treatment is a fungicide microinjection delivered directly into the tree's root flare. The second is a growth regulator called paclobutrazol, which tweaks a hormone in the tree so that some canopy growth is redirected to the feeder root system.
Later in the fall, deep root fertilization addresses micronutrient loss and stimulates feeder root development. Iron treatments, borer control, beneficial microbe inoculations, soil treatments, and vertical mulching are also useful in addressing areas of concern.
Contact us for more information or to set up a post oak evaluation.