Thursday, January 4, 2018
The Jack Pine -Pinus banksiana
The Jack Pine -Pinus banksiana- is a scruffy small tree that grows 40-70 feet tall. The trunk of the Jack Pine generally branches out low to the ground, and will often hold lower branches even after the limbs die. The crown is slender and ragged in form compared to the wider full base. Jack Pine is commercially harvested for pulpwood lumber and round timbers. It is usually found growing in pure or mixed stands in relatively dry areas that are generally unsuitable for other trees to thrive. Jack Pine is considered to be a pioneer species, meaning it is one of the first to appear when mineral soils are exposed by disturbances such as forest fires.
Image Citation: Rob Routledge, Sault College, Bugwood.org
The bark is thin, scaly and dark gray to reddish brown in color. The stalkless cones are one of the easiest means of identifying the Jack Pine. The cones are 1-1.5 inches long and have curved tips near the end of twigs. The leaves are evergreen needles that are 1.5-2 inches long, dark green to gray green in color. Most of the cones remain closed on the tree for many years and can only be opened by the heat from forest fires releasing their winged seeds.
Image Citation: Joseph O'Brien, USDA Forest Service, Bugwood.org
Jack Pines are one of the northernmost of all the Pines. It is recommended for hardiness zones 2a - 7b. The Jack Pine prefers full sun and is considered to be drought tolerant.