Fungus, athracnose, rusts, and root rot sometimes damage trees and wood. Large seed crops are produced each year, and the winged samaras are wind-dispersed, most within a few hundred feet of the parent tree. Green ash of sapling or pole size sprouts readily, resulting in clumps of several stems, and cuttings made from young trees root easily under greenhouse conditions. However no practical way to root cuttings from older trees has been found. This flood tolerant species is almost completely confined to bottomland sites, but grows well when planted on moist upland soils.
Green ash is rated as intolerant to moderately tolerant of shade.
However the northern Great Plains is beyond the range of red maple, and dutch elm disease has limited the expansion of American elm, therefore it apears that green ash is the climax species in these northern Great Plains green ash communities. Green ash, a dioecious tree, flowers before the leaf buds start to enlarge in March to April in Florida, and in late April to early May in Pennsylvania. Male flower buds require 1 to 2 weeks to pass from the unenlarged winter condition to completion of pollen shedding which takes about three days. Female trees begin flower bud enlargement a few days later, and the stigmas are receptive as soon as they emerge from the bud for about a week. Within one month of pollination samaras developing from fertilized flowers reach mature size, although growth and ripening of the embryos is not completed until late September or early October.