How to Get Rid of Black Mildew on Trees


Trees may seem impervious to damage or disease because they are so big and resilient, but the smallest organism can weaken a tree and even kill it if it grows unchecked. If you have spotted black mold spots on your tree, act fast to keep your tree healthy and mold-free.

Step 1

Inspect the tree for black mold and make note of every affected area. The mold may be on branches or leaves, so check both. It may have a smooth or a powdery surface.

Step 2

Prune the tree with sterile shears. Wipe the clippers down with rubbing alcohol in between each cut. Remove all affected branches and leaves. Dispose of the plant material in a sealed plastic bag. Pruning allows more light into the center of the tree, which will help kill off any mold you miss.

Step 3

Rake all plant material from underneath the tree to prevent reinfection. Dispose of the plant material in a sealed plastic bag.

Step 4

Spray the tree down with neem oil. Cover the tops and bottoms of the leaves as well as the bark and branches. This will kill small insects, which are likely the source of the black mildew, and prevent reinfection.

Things You'll Need

  • Pruning shears
  • Rubbing alcohol
  • Plastic bag
  • Rake
  • Ladder
  • Neem oil
  • Pump sprayer


  • Six Non-Toxic Ways to Get Rid of Mold and Mildew
  • North Dakota State University: Deciduous Tree Diseases
  • Our Garden Gang: Basic Pruning Techniques
  • Home Harvest Garden Supply: Natural Insect Sprays
Keywords: black mold, black mold control, trees black mold

About this Author

Carole VanSickle has over five years experience working with scientists and creative scholars to promote and explain their work. She is based in Atlanta, Ga., and specializes in scientific, medical and technical writing, SEO and educational content.