Ailanthus altissima, or tree of heaven, is not recommended to plant, due to this species being highly invasive, spreading underground and via seeds. They are non-native to Ontario, originating from China and North Vietnam. This tree can grow under a variety of soil conditions including poor and rocky soils, but prefers well-draining soils. Despite the tree of heaven�s bright colours and name, this species is currently illegal to plant in Canada. It spreads aggressively, inhibits surrounding plant growth, and attracts both the invasive Spotted Lanternfly, which threatens grapes and the wine industry and the invasive brown marmorated stink bug. With weak wood, it�s prone to storm damage and pests like bagworms and Japanese beetles. It also creates a mess with its litter and emits an unpleasant odour when its bark is scratched. A more suitable species to plant instead is Celtis occidentalis, which are readily available in the nursery industry.