Like all maples, Sienna Glen® Maple can develop Tar Spot (Rhystima spp.) fungus, which is purely cosmetic and unlikely to cause any lasting damage to the tree.
Suckering may be present on old pruning wounds or damaged trunks. While this is best avoided by having a professional arborist care for your tree, suckers can be pruned as they appear to slow/stop their presence. Take care to avoid damaging the trunk tissue as this will cause even more suckers to appear.
Leafhopper, scale, and other insects can feed on the leaf tissues of Sienna Glen® Maple. If excessive damage is observed, or you see individual branches dying (also called Flagging), contact a certified arborist to develop a plant health management plan. Flagging can be a sign of fungal diseases like Verticillium Wilt, which are best diagnosed by a professional.