My baby maple trees' leaves are brown and not falling off. What do you think is wrong with them?
Without seeing a picture of your plant, and knowing a little more about your situation, it's hard to advise you.
I'm assuming you are growing this plant outdoors (they won't be happy indoors, as they require a cold period where they can be dormant).
Leaves that turn brown, but don't fall are sometimes an indication of some sinister issue, usually some kind of root problem, or even a bark beetle of some sort.
These types of issues can cause a lot of damage before it shows, so in some cases by the time the plant is showing signs of distress, the damage is too far along to do anything about it.
One thing you can do, if the tree isn't too big, is to pull the leaves off by hand. There is the school of thought that this enables the tree to go completely dormant by completing the function of the leaves, and it has the added benefit of reducing any pests such as aphids that could overwinter on the leaves ready to attack the already weakened plant.
If you planted this tree, one thing to determine is if the root ball was pulled apart a bit; in many cases, I've dug up a plant that was failing, only to find the roots winding around and around, unable to break out of the shape of the pot they were in.
It's absolutely necessary to prune the roots before you plant the tree if they are at all root bound in this way and spread them out.
If possible, you could dig the tree up while it's dormant to see if this is the case. It won't hurt it any more than it is already. The winter is the best time to do it.
Hope this helps,
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