I have a small mulberry tree (maybe 20ft) next to a much older norway maple. I’m a little concerned about them being so close together. Is this a problem? Do I need to choose one? I’d remove the mulberry if needed to extend the life of the maple.
Norway maples are usually the bullies on the block, so the mulberry is more likely to suffer from being in close competition with the maple. But if it leafs out well and is growing it may be all right. The maple roots will certainly take up the available moisture, but mulberry trees tolerate drought well.
Given the paving stones in the area, you can help both trees by giving them both extra food and water. But the mulberry will definitely need some extra attention in that way. There seems to be a lot of shade on the mulberry at the time the picture was taken. You can have the maple tree branches thinned up high by a professional tree service so that more light can reach the mulberry. This will also be good for the maple since it will prevent future the winter storm damage to which they are vulnerable. (And protect your house.) Maple trees should be pruned in the fall or winter since the cuts will “bleed” if pruned in the spring when the sap is rising.