What is Oak Leaf Blister?

Date February 19, 2019


Author TreeNewal Staff


As an arborist in Denton County, TX I see many ailments, diseases, and impairments on trees daily. Trees planted too deep or ones that are over-pruned are other common issues as well. Although each of these topics is important and worthy of discussion, because of the time of year, I’d like to discuss the seasonal concerns of oak leaf blister and Spring fertilization.

How to Identify Oak Leaf Blister

Oak Leaf Blister or Oak Leaf Curl is a foliage fungal disease caused by the fungus Taphrina caerulescens. At first, Oak Leaf Blister may be hard to detect, but soon you will notice brown spots on the leaves which can be quite noticeable as the fungus spreads to the canopy. Once the leaves are infected, they will stay discolored and possibly de-foliate and fall from the tree for that growing season.
Oak Leaf Blister can become a serious issue if it goes untreated over several seasons, especially if the tree has other negative stressors such as drought, soil compaction, over-watering, or nutrition deficiencies. Red Oaks are typically most susceptible to this fungal infection, but we have seen many Live Oaks in Denton County with Oak Leaf Blister as well.

The solution: Spring Fertilization

The only time treatment is effective is in the early Spring before the buds begin to break with new growth. Spring fertilization proactively treats for Oak Leaf Blister and is overall good to maintain the health of the tree. Proper pruning helps, but a maintenance fertilization schedule can vastly improve the health of a tree in our suburban environment.

Imagine how in a forest, every year, the leaves that fall become part of a decomposing nutrient-rich layer on the forest floor. Lawn maintenance and leaf raking in our lawns and greenspaces prevent this decomposition layer from forming. Our green, monoculture front lawns look excellent, but there is a big difference to the tree! This lack of nutrients and biodiversity in the soil is one of the key factors leading to tree disease and why it is essential to maintain your trees through fertilization.
Call us at tel:(817) 592-6846 for these tree services and more, including pruning, removals, and plants, or visit our website at www.TreeNewal.com.

Jorge Gaona – ISA Certified Arborist TX-4404A
TreeNewal your sustainable Tree Care Company.