Maple Tar Spot
Does your maple leaves look like this?
As beautiful as our gardens are its normal to have some problems and diseases in them. This does not in any way mean you are not a good gardener. It simply means diseases happen throughout nature.
Maple trees have absolutely gorgeous yellow, orange and red fireballs every fall – and I look forward to it with a great deal of anticipation. When I first saw Tar spots on my Maples I thought it spelled the end to beautiful fall scenery forever.
But, maple tree tar spot is a minor disease of maple trees and you’ll have plenty of fiery falls to come.
If your Maple leaves look like this it has Tar Spots.
Tar spot is a fungal disease that causes black tar-like spots on the leaves of red, silver, Norway, sugar and Manitoba maples. ). Tar spot is a foliar disease: the spores do not affect other parts of maple trees.
Maple tar spot is a very visible problem for maple trees. It starts with small yellow spots on growing leaves, and by late summer these yellow spots expand into large black blotches that look just like tar has been dropped on the leaves. This is because a fungal pathogen in the genus Rhytisma has taken hold.
The fungi responsible for tar spot disease survive the winter on fallen leaves. If these leaves remain in the yard, fungal spores are spread to maple trees in the spring. Spores are produced in the remaining fallen leaves and are carried by air currents to newly emerging maple leaves.
Luckily Japanese Maples are not susceptible to Tar spots.
How To Control Tar Spots….
Because of the way maple tar spot disease is transmitted, complete control of maple tar spot is virtually impossible on mature trees. Prevention is the key with this disease. But if nearby trees are infected, you can’t reasonably expect to totally destroy this fungus without community support.
Start by raking all your maple’s fallen leaves and burning, bagging or composting them to eliminate the closest source of tar spot spores. If you leave the fallen leaves on the ground until spring, the spores on them will likely reinfect the new foliage and start the cycle again.
Trees that have trouble with tar spots year after year may also be struggling with excessive moisture. You’ll do them a great favor if you increase the grade around them to eliminate standing water and prevent moisture build-up.
So don’t worry Maple Tar spot will hinder you beautiful Maples from showing their fall color. Its just a cosmetic problem.
So make sure you rake the leaves and burn them.