Maple Tar Spot

Tar Spot

Seeing black spots on your maple leaves can seem a bit disappointing especially when you’re really looking forward to the reds and oranges that autumn brings. These spots are called “tar spots” and they are a minor disease common on maple trees. Tar spot shows up as a yellow spot on leaves in early summer and slowly become dark black by mid to late summer. This disease only affects leaves and not the rest of the tree, thus it is primarily a cosmetic issue.

Trees that are prone to Tar Spot include Norway Maples, Silver Maples, Boxelder Trees, and Willow Trees

How to Identify Maple Tar Spot

Early Signs:

● ~⅛ inch yellow spots on leaves in early summer

Late Signs:

  • ~¾ inch black spots on leaves in mid to late summer

Maple Tar Spot Prevention

For Homeowners:

  • Maple tree tar spot spreads through the air from leaf litter
  • Rake up and dispose of fallen leaves to help prevent the spread of tar spot
  • Maintain the vigor of your maple trees

Maple Tar Spot Prevention

For Professionals:

  • Properly diagnose the issue
  • Apply preventive fungicides as appropriate

Tree Tar Spot FAQ

Step 1

Proper diagnosis from a Certified Arborist

Step 2

Preventive Fungicide applications early in the season

Tree Tar Spot FAQ

Will Tar Spot kill my maple tree?

No, tar spot only affects the leaves, not the entire tree. Because of this, the health and integrity of the tree is rarely affected by tar spot.

Will tar spot return in the spring?

Tar spot is spread from the wind. If there are leftover spores from the previous year’s affected foliage, your tree can be infected year after year. This is why it is a good idea to thoroughly dispose of leaves in the fall.