Description & Overview
Pinus banksiana, the Jack Pine, is one of Wisconsin’s three native pine trees, home to our northern dry forests, sandy plains, and sandy savannas. This coniferous tree can eventually reach heights of up to 50 feet. In youth, its habit is open and straggly; once mature, it becomes more upright with irregularly spreading branches and grayish-brown scaly bark.
Unfortunately, the Jack Pine population in Wisconsin has steadily decreased since 1983, largely because it is an important timber species. According to the Wisconsin Department of Natural Resources, Jack Pine accounted for 13.5 million cubic feet of Wisconsin’s roundwood production in 2013!
Jack Pine’s native range resides primarily in Canada and is most abundant in Ontario; however, the largest acreage of Jack Pine in the United States can be found here in Wisconsin, Minnesota, and Michigan. There are small populations in northern Illinois, and are a state-listed endangered species. For entire regions in Wisconsin, Jack Pine adds character and wildlife value to some of the leanest and driest soils we have to offer. Its scrubby nature and proclivity to fire make it a wonderful addition to Wisconsin flora. Along with Northern Pin Oak, these plants make the ‘scrub’ of Wisconsin’s sandy landscapes.
Jack Pine is usually found growing on sandy soils with lower pH. Its natural habitat includes sandy woodlands, sandy savannas, sandy prairies, rocky sandstone cliffs, and stabilized sand dunes along Lake Michigan. This species thrives in dry, barren areas with a history of fire. The species is only moderately resistant to fire; however, their seeds germinate in response to heat and greater amounts of sunlight. It grows best in well-draining, loamy sands. Jack Pine struggles with alkalinity and will not grow well where the soil surface is alkaline, but it can grow on soils overlying limestone. This tree is rarely used as a landscape tree but makes a fine addition to native restoration projects where soils are more acidic.
Jack Pine provides food for numerous wildlife species. Upland gamebirds like wild turkeys and songbirds like warblers, nuthatch, and goldfinch eat the seeds. Small mammals like squirrels and mice also enjoy snacking on Jack Pine seeds. White-tailed deer browse on the foliage and twigs of pines, particularly during the winter, while the Cottontail rabbit browses on young seedlings and gnaws on the bark of saplings. Thanks to the dense layers of foliage, Jack Pine also makes a good nesting and roosting site for many species of birds. The federally endangered Kirtland’s warbler has been seen nesting at the base of Jack Pine, where the tree is the dominant species. One of the largest and rarest warblers, the Kirtland’s Warbler only breeds in young Jack Pine forests in Wisconsin and Northern Michigan. Plant more Jack Pine!
Proper care begins with proper siting. Remember that Jack Pine wants to grow in slightly acidic sandy soils with good drainage. This species is highly shade-intolerant, so be sure to plant it in a suitable location with plenty of sunlight. Because this tree is rarely used as an ornamental or landscape specimen, aesthetic pruning is not often performed. If pruning is desired, the best time to do so is late fall, winter, and early spring.
Jack Pine budworm is the primary insect pest. It is a native moth species whose larvae feed on various pines, although Jack Pine is a favorite. The budworms spend winter as nonfeeding second-stage-instars and eventually emerge as caterpillars in spring and begin to feed. The larvae spend approximately the next six weeks gorging themselves before pupating. The budworms are defoliators and feed on the foliage, new shoots, and buds. If a tree is significantly defoliated, it will likely have reduced growth for two or more years afterward. Crown dieback is common after heavy infestations, and repeated severe infestations may result in the tree’s death.
Keeping your tree happy and healthy is the best way to prevent this insect. Budworm infestations tend to develop in trees that are under stress or injured. Using other plant species that help support the local bird populations may also help control budworm populations in smaller pine stands. Chemical control is sometimes necessary; consult an ISA arborist near you for assistance with control.
The species was named in honor of Sir Joseph Banks (1743-1820), a British naturalist and former President of the Royal Society from 1778 until 1819.
Pinus banksiana is an important commercial timber species in the United States and Canada. The moderately hard and heavy wood is used for pulp, lumber, poles, fence posts, mine timbers, and railroad ties.
Currently, the largest Jack Pine is a specimen in St. Louis County, Minnesota standing at 73 feet tall with a crown spread of 39 feet and was crowned the national champion in 2018.
In 1973, an experiment was conducted to better understand tree physiology which studied winter frost resistance, analyzing germination percentage and seed survival at extremely low temperatures. Seeds of four conifers, Abies balsamea, Pinus banksiana, Pinus strobus, and Thuja occidentalis, were immersed in liquid nitrogen at -384.8°F and were all able to survive (A. Sakai and C.J. Weiser 1973)
Large acreages of this forest type were cut and burned during the late-19th and early-20th century logging. Much of this land was then colonized by Paper Birch (Betula papyrifera) and Quaking Aspen (Populus tremuloides).