Brown spots on maple leaves don't just look unsightly. In some cases they also indicate a serious problem. Here you can find out what the causes of the stains can be and how you should react.
Why does the maple tree have brown spots on the leaves?
Brown spots on maple leaves can be caused by maple scab (tar spot disease), moisture problems, sunburn, or verticillium wilt. Depending on the cause, affected leaves should be removed, watering adjusted or location changed.
When do maple leaves get dark brown spots?
Clearly defined spots on the maple leaves indicatemaple wrinkled scab. As the name suggests, the maple (Acer) in this case develops distinctive spots that look reminiscent of scab. Since the spots in this case have a very dark, sometimes black color, the disease is also known as tar spot. The dark spots are outlined in yellow. The damage is caused by fungal infestation. The disease also causes early fall of foliage in summer.
How do I treat a maple tree with tar spot?
It is important that you collect theleaves infected with fungus and dispose of them correctly. Here's how to proceed in this case:
- Get the garbage bag ready
- Collect affected leaves.
- Burn leaves or dispose of them in closed trash.
Only through proper disposal can you ensure that the fungus does not spread in the soil. Then next year the maple will have normal leaves again without spots.
What else causes brown spots on maple trees?
AlsoMoisture can in some cases lead to brown spots on the maple. In these cases, however, the leaves are more likely to dry out completely. So you won't notice dry spots on the individual leaf, but on the entire foliage of the maple. In this case, check the soil under the maple for moisture. Both excessive dryness and waterlogging can cause parts of the maple to dry out. If in doubt, you should water maple differently, mulch it or add a drainage layer.
Is sunburn the cause of brown spots on maple trees?
If brownleaf spotsappear on thetips of the maple leaves, sunburn is also a possible cause. This type of stain occurs primarily on young specimens of Japanese maple.
How do I rule out verticillium wilt as the cause?
If you check the condition of themaple bark, you can rule out an infestation by Verticillium wilt. An infestation doesn't just cause spots on the leaves. Parts of the bark split open. The wilt can also spread to other plants. It is important that you react quickly here. Consistently cut back or cut down infected trees. Dispose of the clippings in a closed trash or burn them.
Tip
Choosing the right location prevents problems
You can avoid brown spots and other problems on maple trees by choosing a suitable location. If the maple tree has enough nutrients and is neither too wet nor has to deal with drought stress, it is less susceptible to problems.