Juglans cinerea. Considered an endangered species in Ontario, Butternuts grow naturally along sunny stream banks with rich, well-draining soil, and while they can survive in zone 2, they must be within zone 3 to produce nuts. The nuts are quite similar to a walnut but with a milder flavour. Sap can be boiled to make walnut syrup, which tastes very similar to maple syrup but with notes of caramel and butterscotch.
Be mindful of the juglones in the in the roots/nut husks, they are toxic to many other species. They require a buffer of about 50'/30m from the edge of the trees canopy for juglone-sensitive plants. This article from PennState Extension has a helpful list of plants that tolerate juglones.
Butternuts have become endangered thanks to a fungal disease called Butternut Canker. Within 2 decades, the Canker has decimated the native population. By planting endangered species, collectively we can help Mother Nature find a naturally resistant variety of Butternut.
Canadian Hardiness Zone: 3
Recommended Use: nuts used for fresh eating, cooking or baking, or syrup enjoyed as you would maple syrup.
Ripens: October for nuts, March for sap
Height not including roots: 30cm one year seedling