Tar Spot Mold attacking Maples.

[Lowell]

I am seeing severe instances of tar spot fungi attacking Black maple trees this year. Anyone else seeing the same?
http://plantclinic.cornell.edu/FactS...t/tarspots.htm
Attachment 6815

[kellyroad]

I am seeing severe instances of tar spot fungi attacking Black maple trees this year. Anyone else seeing the same?
http://plantclinic.cornell.edu/FactS...t/tarspots.htm
Attachment 6815

I planted a couple of emerald queen maples last year in the late summer, by fall there were a few tar spots on the leaves. I was thinking the worst, being new trees with tar spots already appearing. The leaves did reappear this spring, and there are only a few spots on one of the trees. However the season is early. The other maples, an established 40 year old American maple and a full Japanese maple show no sign of black tar fungi. It is, as your website suggests, a cosmetic problem. Hopefully, this does not become a dutch elm or emerald ash like concern. BTW, I live 15-20 miles south of downtown Detroit and haven't seen this as a general problem in our area.

[RO_Resident]

I have a maple that has got the tar spots for the past couple of years. The tree also gets maple gall mites--some leaves get covered in growths that look like warts.
http://www.fcps.edu/islandcreekes/ec...te/4212018.jpg

[softailrider]

When the leaves fall, DO NOT grind them up into your lawn. That can be transferred to your grass. Not a lot of fun getting ri of it.

[Jimaz]

At least one of ours seems to have it. The other four are too tall to see the leaves easily.

[gencinjay]

My maple has had some kind of growth the past couple years. It looks kind of like caterpillars sticking up from the leaves. Each leaf will have dozens of them on it. The trees on the top of the tree will wither much sooner in the year because of it.

[detroitbred]

We have 2 good sized Norway Maples that have looked sick the last couple of seasons. They start out fine, but by this point in the seaseon have nearly one whole side that has yellowed leaves and rusty looking spots on them, and some dead branches. We lost another maple a couple years ago, and it looked the same way. I would hate to loose these two, just not sure what is wrong with them. Any ideas anyone?

[canuck]

We have the same problem up here in Quebec and in Vermont and New York states.

[goggomobil]

Lowell, that looks like Maple Leaf Anthracnose, also a fungus.

Tar spot is usually a distinct large black spot. I had this on some Norway maples and it never completely went away.

The best way to deal with tar spot is, in autumn, to rake up every single leaf [[as far as practical from the tree's dripline) and send them to the landfill or burn them, if you can. If they are sent to be composted, the fungus will be spread all the more. If it's a baby or a dwarf tree, you might be able to apply a fungicide. It never goes away, but raking really minimizes it.

gencinjay, that's maple leaf spindle, caused by a mite.

detroitbred, maybe verticillium wilt. Could be girdled roots or a soil anomaly on one side of the trees. Also might be sunscald if it's dying on the sunny side. If you have a tree with co-dominant trunks and one is dying, it could be a number of things.

[detroitbred]

goggo...I think you are exactly right, it is Verticullum Wilt that my trees have. The tree we lost and the 2 that are sick are all on the same side of my house, leading me to believe the soil is infected there. I have two other huge Norways and a Crimson King on the opposite side of the house and they are fine and healthy. Now the question is, can I save the two sick ones? I am going to water them heavily, and check out the anti fungus options at the store to see if there is anything that can be added to the water for the trees to "drink". Do you have any ideas along that line? Thanks for your input!!

[courtney]

Verticillium wilt is in the soil. Even if you were to get rid of the tree in the area affected, it would still live in the soil for years so make sure you do your research to not put in a variety of tree that is prone to being attacked.

Prune out the affected branches/limbs and make sure they get enough water and a good organic fertilizer [[not something high in nitrogen). Remember to disinfect your pruning tools between each cut. You can probably milk at least a few more years out of them. No known fungicides have been shown to have much of an effect. The affected roots get gummed up and can't suck up anything, which would make them unable to get any benefit from a fungicide.

That being said, we just got rid of an ornamental cherry that was showing signs of being infected for the past couple of years. Could I have babied it and made it last for another couple of years? Sure. However, in a couple of years, we wouldn't have been able to take down the tree ourselves and would have had to pay hundreds to have it done since it was next to the power lines that supplied our house and our neighbours. I will also be able to plant something in its place this fall instead of waiting for the coming death of the old tree.

A short list of resistant/susceptible trees can be found at http://www.extension.umn.edu/distribution/horticulture/DG1164.html .

[goggomobil]

If it is verticillium wilt, nothing has proven to be effective against the disease. The disease spores affect the xylem [[water veins, so to speak) and thus prevent transmission of injected fungicide-bearing liquid.

You can only prune the affected parts and water, water, water, or remove the trees. Copper octanoate is an organic fungicide [[available from ACO; Bonide, 32 oz., about $8) if you're in the mood for a what-the-heck last chance effort. Try injecting it into the dripline at least 6" to 12" into the soil on the affected side.

[fulldocket]

Thanks for the information. The leaves on the top of our maples have the tar spot. The bottom half is fine.