Aesculus hippocastanum, or common horse chestnut, is non-native to Ontario with a natural range in the Balkans in Europe. Cultivars are commonly found in the nursery industry but are not recommended to be planted in urban settings as it produces poisonous nuts and may have invasive tendencies adjacent to naturalized areas. This species grows in nearly any urban soil, including alkaline soils. They are resistant to most diseases and pests but are prone to leaf scorch, powdery mildew, bark and leaf blotch (not serious threats). The species is considered extremely messy, producing prickly seed pods and bark debris, but cultivars such as Aesculus hippocastanum (Baumannii), are available where the fruit is nearly absent and can be a better choice for urban street tree plantings. The horse chestnut is related to the Ohio buckeye and is easily distinguished by its spiny fruit and sticky buds. It is difficult to transplant but does demonstrate tolerance for clay texture, alkaline pH, and road salt soil, while producing stunning spring flowers.