Tar Spots on Norway Maples

[Diolated]

Anyone have problems with Tar Spots on their maples? I have a few very nice Norway Maples that I dug up a few years ago -- great great yamadori, but they suffer from tar spots every year (just like all the Norway Maple do in the area). They drop their leaves early, and look like shit from about July to August. I read you can treat tar spots, but I'm curious if anyone has done so and what type of success was had. Thanks in advance for any thoughts.

 

[Cypress187]

Are they on the leaves or on the trunk?

 

[Dav4]

Anyone have problems with Tar Spots on their maples? I have a few very nice Norway Maples that I dug up a few years ago -- great great yamadori, but they suffer from tar spots every year (just like all the Norway Maple do in the area). They drop their leaves early, and look like shit from about July to August. I read you can treat tar spots, but I'm curious if anyone has done so and what type of success was had. Thanks in advance for any thoughts.

I've seen tar spot on landscape Norway maples many times so I think they are prone to it. The fungus is in the soil around the trees, so the best thing to do in my opinion is to remove any affected leaves and toss in the trash. I suppose preventative spraying as the leaves are opening in the spring may help.

 

[Diolated]

Are they on the leaves or on the trunk?

Just leaves.

 

[Diolated]

I've seen tar spot on landscape Norway maples many times so I think they are prone to it. The fungus is in the soil around the trees, so the best thing to do in my opinion is to remove any affected leaves and toss in the trash. I suppose preventative spraying as the leaves are opening in the spring may help.

I've read about preventative spraying in the spring and good leaf hegiene Dav4. Thx for the response

 

[Leo in N E Illinois]

If tar spot is active on your local trees, it will be difficult to control. Picking up all the fallen affected leaves within 1/8 mile of your tree will be a lot of work.

Check the label for Cleary's 3336, or any other systemic fungicide. But only use a fungicide if it specifically lists tar spot. If it is not listed, assume it won't work. Follow directions on label.

 

[Diolated]

Thanks for the response Leo.

If tar spot is active on your local trees, it will be difficult to control. Picking up all the fallen affected leaves within 1/8 mile of your tree will be a lot of work.

Check the label for Cleary's 3336, or any other systemic fungicide. But only use a fungicide if it specifically lists tar spot. If it is not listed, assume it won't work. Follow directions on label.

 

[AlainK]

I know why there is no sub-forum "pests and diseases"!

There are so many, and some are very difficult to identify, especially for maples.

On top of that, a disease is more prone to develop on a weak tree than on others, so the first cause could be chlorosis, or or even on two trees that look exactly the same but have different genetics (not to mention "new ones" or "imported ones" like the dutch elm disease, asian hornet, etc) :

Chalara dieback of ash, also known as Chalara or ash dieback, is a disease of ash trees caused by a fungus called Hymenoscyphus fraxineus.
(http://www.forestry.gov.uk/ashdieback)

It's become catastrophic in Britain and will no doubt affect other areas in Europe (Brexit won't save us!).

The best "solution" so far seems to be to select specimens that are more resistant and clone them to replant the affected areas.

But for us, if it reaches where we live, what we can say to our 10 or 20 yr-old trees is bye-bye, cheerio, fare you well, and even perhaps so long (it's been good to know you)...