Scientific Name
Pinus banksiana
Jack pine is native to much of Canada and extends into Minnesota, Wisconsin, Michigan and Maine. It is one of the hardiest pines and can tolerate temperatures below minus 40°F. Few horticultural sources give it much attention beyond describing it as a plant of last resort for poor soils and harsh climates, often noting its lack of refinement compared to other pines. Despite that reputation, it has been included in the arboretum and shows clear value under difficult conditions.
Its short, dark green needles, one to two inches long, are produced in bundles of two. The tree typically has an open, somewhat irregular habit. It may exceed 40 feet in height, though the Colorado champion in Denver is about 28 feet tall after many decades. The Regis specimen, at about 16 feet after 12 years, is already second on the Colorado champion list.
Seed cones are about two inches long and curve toward the branch tips, often remaining closely appressed to the branches. They are adapted to fire regimes and may remain closed for many years, though they will open here as well. Jack pine is not commonly encountered in this region, but it demonstrates that suitable planting sites are more common than often assumed.