4 Trimming Tips To Combat Powdery Mildew In Trees

Powdery mildew is a common problem on some trees. It typically appears as a white or sometimes gray powdery coating on leaf surfaces, occasionally spreading onto small twigs. Mild infections are little more than a cosmetic issue, but an extensive powdery mildew infection can prevent foliage from properly photosynthesizing. This may not kill the tree, but it does stress its health which makes the tree more susceptible to more damaging diseases and pests. Reducing fertilization and keeping the foliage dry can help prevent powdery mildew from getting out of hand when combined with proper pruning.

1. Open Up the Crown

Damp and shady conditions are perfect for powdery mildew. Poor air circulation can also help the fungus thrive. Opening up the crown by thinning out some of the excess branches allows for air circulation, which dries out excess moisture, and it also allows more sunlight to penetrate more deeply into the tree. Your tree pruners will remove the weakest branches first, then thin out the remaining as necessary to ensure proper air circulation and sunlight access.

2. Reduce Overcrowding

Trees growing too closely together or those with branches growing right up against a building can also suffer from poor air circulation and trapped dampness due to overcrowded conditions. Trimming back the branches on all the trees involved can give some space so that airflow isn't compromised for any of the trees. Generally, tree branches can be trimmed back by about a quarter of their length. This may seem like a small amount, but it can still have a big impact when it comes to reducing powdery mildew.

3. Remove Infected Branches

Powdery mildew typically resolves on its own once air circulation is restored and weather conditions begin to warm up, but sometimes the infection is so severe that damaged branches remain a problem. Badly infected twigs and branches are sometimes best pruned out. Not only does this help prevent the spread of mildew, but it also removes the badly weakened wood that is now more susceptible to other pests and diseases.

4. Clean Up Thoroughly

Cleanup is important for powdery mildew repair and prevention. All the fallen twigs and branches need to be raked up and disposed of so that the mildew spores aren't left in the environment to spread to other plants. Pruning tools will also be disinfected so that no spores remain present to spread the disease a second time.

Contact a tree pruning service for more help with the management of mildew infections in your landscaping trees.