Description

The black walnut is native to eastern North America, ranging primarily from southern Ontario to the southern United States. The Niagara variety is native to the mature forests of the Carolinian region in southern Ontario. It can live up to 250 years under ideal conditions. The black walnut produces juglone, a chemical released by its roots that inhibits the growth of many nearby plants. Many native trees tolerate this substance, but it must be taken into account in landscaping plans. It tolerates a wide range of pH levels, but it is best to plant it in deep, fertile soil. The Niagara variety is known for its exceptional size.