Norway maple vs Sycamore maple

It is susceptible to verticillium wilt, which kills branches suddenly and cannot be cured. Winter sun can crack and scald the bark of young trunks. In the hot, dry summers of Central Europe, especially in paved urban settings, leaf margins scorch, and powdery mildew and tar spot are common on the foliage; stressed trees drop their leaves early. The shallow roots heave pavements and driveways.

In Central Europe this is a hill and mountain species that needs humid air: in hot, dry lowland summers the leaves scorch and drop early and the tree weakens. Trees stressed by heat and drought are increasingly hit by sooty bark disease (Cryptostroma corticale): the bark peels away to reveal a black, soot-like mass of spores, branches die and then the whole tree. Inhaled spores can cause an allergic inflammation of the lungs in people, so have a diseased tree felled by professionals with protective equipment. Sycamore aphids drip sticky honeydew onto cars, paving and furniture below. Tar spot (black blotches on the leaves) is common, ugly but harmless. It seeds itself heavily and seedlings need pulling out of beds regularly.