
Almost nothing that matters — small leaves that break down quickly and light paired samaras that will not clog a gutter. The nuisance is seedlings, since NC State notes the species self-seeds readily and the volunteers come up plain green rather than red, so they get weeded out of beds every spring.
15-25 ft tall by 10-35 ft wide, slow to moderate growth, hardy in zones 5a-8b, with dwarf and laceleaf cultivars staying under 10 ft. Removal is the cheapest line on any price list — hand crew, no climbing, one chipper load — but replacement is not, since a matched 10 ft specimen is a four-figure nursery item, and life expectancy here is set by verticillium, winter injury, and root disturbance rather than by age, so preservation almost always beats removal.