Yellowish Maple Tree

[BillNole]

I have a dozen maple trees on my lot of various ages and types. All are volunteers of some sort, having either been dug up elsewhere and transplanted, or they've popped up where they stand now. The first 4 were transplants, of which three are still standing. One of them just never seemed to do well and and was always just a little punky compared to most others. I finally knocked one down last year that hadn't grown more than about 6 feet tall in over 15 years. I have another that while it's better, it isn't what it should be. (Photo attached...)

In the photo, you can see the one I'm talking about in the foreground. Behind that one and along the fence is another that was about the same size (Maybe 2-3' tall) when both of them were first transplanted, again about 15 years ago. The one in the back looks relatively nice and is seemingly doing well, while the one in the foreground appears yellowish, with leaves that also appear to be smaller and just not as robust as others. This was the same issue with the one I knocked down last year, although it was much worse. They all came from the same area when dug up and might even be from the same "parent" tree from all I know, since I dug them up from my in-laws property.

Any ideas as to what the issue might be? It seems like some sort of nutrient deficiency of sorts to this untrained eye, but I don't want to just dump a bunch of remedies on the ground and hope for the best. If it can be saved, I'd rather do so. If not, I could put another in it's place if I could feel relatively confident it won't do the same, I might just cut it down and avoid the mowing annoyance.

 

[ATH]

1) Check the planting depth. Can you see where the trunk flares out to the roots? That should be at ground level.

2) Have you had a dry summer?

3) Mulch is a tremendous help - NOT piled against the trunk...2-3" thick in a large circle and pulled away from the trunk itself.

4) The most likely problem is manganese deficiency. Get a soil test - I'm betting the pH is going to be 7 or higher. In high pH soils, maple trees have trouble getting manganese. It is often in the soil (a good soil test will tell you if it is or not). The long-term fix is soil improvement. If the soil test does show high pH, mix some garden sulfur in the mulch once or twice per year. There are foliar sprays and trunk injections that will immediately solve the yellowing leaves, but they are temporary fixes. You need to work on the soil, and that is a long-term commitment. Unless they are in really bad shape, I wouldn't even do the injections. Mulch also helps improve the soil and slightly lower the pH.

 

[BillNole]

1) Check the planting depth. Can you see where the trunk flares out to the roots? That should be at ground level.

2) Have you had a dry summer?

3) Mulch is a tremendous help - NOT piled against the trunk...2-3" thick in a large circle and pulled away from the trunk itself.

4) The most likely problem is manganese deficiency. Get a soil test - I'm betting the pH is going to be 7 or higher. In high pH soils, maple trees have trouble getting manganese. It is often in the soil (a good soil test will tell you if it is or not). The long-term fix is soil improvement. If the soil test does show high pH, mix some garden sulfur in the mulch once or twice per year. There are foliar sprays and trunk injections that will immediately solve the yellowing leaves, but they are temporary fixes. You need to work on the soil, and that is a long-term commitment. Unless they are in really bad shape, I wouldn't even do the injections. Mulch also helps improve the soil and slightly lower the pH.

Thanks for the quick and detailed reply ATH!

1) Yep!
2) Yes and no... We've gone through a number of swings of dry spells and wet periods this summer. You can see from the lawn in the image that we're enjoying a rather wet period over the past couple of weeks. (I don't irrigate, but prefer to let it go dormant during dry spells and the heat of Jul/Aug...)
3) I have mulch "circles" around several trees and always make a point to not pile anything directly against the trunk and pull anything back a few inches to avoid rot and bug issues.
4) I've long suspected some sort of deficiency. I'll pick up a PH test kit this weekend and see what it says and then go from there.

Thanks again ATH for your kind help! I do like where I've placed each tree and bush, or I wouldn't have placed them there! Haha... Our's was a lot with a house and grass when we first moved in, like most others in the development. 20+ years on now, most have well established trees and greenery and I'd like to do my part to ensure our's is a positive influence and not a detraction.

You have helped someone today!