How To Get Rid of Black Fungus on Trees

Who doesn’t want their trees to remain healthy and beautiful for years to come? Unfortunately, a lot will threaten your tree’s longevity.

For example, one threat your tree will face stems from black fungus. This common fungal disease causes your tree to form swollen black knots. Without fungus treatment, the disease can lead to your tree’s death.

Are you worried about your tree’s health? Read on as tree specialists in Holliston, MA, show you how to get rid of black fungus on trees.

how to get rid of black fungus on trees

Signs of Black Fungus

Also called black knot, black fungus refers to a disease caused by Apiosporina morbosa. The fungi release spores that land on your tree and shrubs, causing branches to form black, hard, and swollen knots. These knots start off small and green and turn black as the disease progresses.

Fortunately, you don’t have to be a pro to detect black fungus on your trees. The black knots on your tree’s branches give you a telltale sign.

Other common signs of the disease you can look for include:

  • Brown, wilting leaves
  • Branches tilting to one side
  • Sticky liquid oozing from the knots
  • Wood rot

How To Get Rid of Black Fungus on Trees

As deadly as black fungus can be, you can still treat it. However, for your trees to have the best chances of survival, you’ll need to act quickly.

Read on to learn how to get rid of black fungus on trees.


One of the best ways to rid your tree of black fungus is to prune the twigs, stems, or branches where you see the infection.

Making the cut about two to four inches below the knot will do the trick. Just be sure to burn or dispose of the parts you cut carefully because they can still spread the infection to a susceptible tree.


On top of pruning, you can also treat black fungus by using fungicide. We should note that fungicide treatments vary in their effectiveness, so you should pay attention to the products you pick.

Ideally, you want to pick a fungicide with ingredients like lime sulfur, captan, thiophanate-methyl, and chlorothalonil. Also, be sure to remove the existing knots before applying your fungicide of choice.

Can I Prevent Black Fungus

Though black fungus can affect your trees, you can keep it at bay with proper maintenance and regular monitoring.

You could also choose to plant trees resistant to black knot. In fact, doing so offers the best way to keep your trees safe.

Professional Arborist Services in Holliston, MA

The last thing any tree owner wants to see is their tree succumbing to disease. Fortunately, with quick action, you won’t have to worry about black knot claiming your tree.

Have you noticed signs your tree is dying? Turn to Brooke Tree Service and let us help you learn how to get rid of black fungus on trees. You can trust us to offer solutions that will restore your tree’s health.

Call Brooke Tree Service today at (508) 613-5044 to request an estimate.


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