The jack pine is a tree that cannot be tamed—it grows its own way and takes over with large stands of growth even where wildfires have left the land barren. At the same time, these conifer trees are practically maintenance-free and make a hardy addition to any landscape that is characterized by poor, rocky soil.
The mature height of a jack pine tree varies, based on environmental factors. If growing conditions are less than ideal and sun is limited, then these trees will stay more shrubby. They often feature a twisted growth pattern and have been known to grow somewhat sideways. With full sun and a good loam soil, they can grow between 30 and 70 feet tall.
The somewhat patchy canopy of a jack pine tree means that they allow for shade-tolerant plants to grow beneath their branches. If you’re looking for an evergreen tree that won’t steal all the sun from surrounding plants, then the jack pine might be a good choice.
|Botanical Name||Pinus banksiana|
|Common Name||Jack pine|
|Mature Size||30 to 70 feet high|
|Sun Exposure||Full to part sun|
|Soil Type||Dry, sandy|
|Flower Color||Not Applicable|
|Hardiness Zones||2 to 6|
|Native Area||Canada, Northern United States|
How to Grow Jack Pine Trees
The jack pine tree won’t demand much of your time and attention. These easy-keepers grow prolifically in conditions that might seem inhospitable—especially on barren, stripped soil in the wake of wildfires. They won’t demand much if you plant them in your yard or landscape.
No special considerations need to be made to water these trees, and they generally never need fertilizer, since they do well in bare mineral soil. They’re drought tolerant, but prefer temperate summers and cold winters. You can try to manage the appearance of the wayward growing branches with pruning, but most people accept the jack pine as it is.
Pests can be a problem if insects like the jack pine budworm or other boring insects arrive on the scene. The best defense for a pine tree is health and vitality, so if your jack pine is planted in a location with plenty of sun and provided water during extended periods of drought, it’ll be more insect and disease-resistant.
Jack pine seedlings are dependent on full sun at the start of their growth cycle, and these trees do best with at least 6 hours or more of direct sun throughout their life cycle. In fact, lower branches of the tree sometimes die because of being shaded from the sun’s rays by the tree’s canopy.
The jack pine is able to adapt to very dry soil conditions and is often found in sandy soil. However, its been noted that its preference is for loamy soils that have a mix of clay, sand, and nutrient-rich humus material. Generally, jack pine trees prefer acidic soil but can grow in some alkaline soils if the conditions are right.
These trees often do well in soil that has been ravaged by wildfires and are quick to spring up in the bare mineral soil.
Jack pine is not dependent on an abundance of water. This drought-tolerant tree species would much prefer dry conditions to being swamped in wet soil. As a hardy conifer, its unlikely that you’ll have to supplement this tree with a regular watering schedule. Unless extreme conditions prevail, the jack pine is generally satisfied with the annual rainfall it receives.
Temperature and Humidity
The jack pine exhibits tremendous hardiness in the cold, and can survive even the frigid winter temperatures of USDA hardiness zone 2. However, they don’t fare so well in hot, humid summer conditions and prefer climates with short, warm to cool summers. It’s no surprise, then, that these trees are often found in the greatest numbers in the United States in the states of Michigan, Minnesota, and Wisconsin.
These trees grow where few other plants dare to—preferring the bare mineral soil of sites recently ravaged by wildfire. These trees thrive in low nutrient soils, so it’s unlikely that you’ll need to fertilize the soil surrounding a jack pine tree. Cross this task off your to-do list if you plant a jack pine tree in your yard!
Propagating Jack Pine
If you’re looking to multiply jack pine trees, the tightly sealed pine cones hold the key to propagation. Inside these cones, which can remain sealed for decades, are plenty of seeds that can sprout new jack pine seedlings. Choose pine cones that are mature, which is generally indicated by a changing of color in the fall. Trees generally need to be 3 to 5 years old to serve as a seed source.
Once you’ve collected the seeds of a jack pine tree, you’ll need to coax the cone to open. Under natural circumstances, heat (usually from a wildfire) is responsible for loosening the resin that holds the cone closed. No need to toss these pine cones in the fire to gain access to the seeds inside. Instead, you can soak the cones in hot water for 8-12 hours and then set them in the sun and wait for them to open.
Germination happens quickly with jack pine seeds, and as mentioned earlier, these plants don’t require anything more than bare mineral soil to get started. However, the seeds will sometimes need a quick cold stratification to jolt them from their dormancy.
The jack pine tree is known for its free-styling nature and tends to grow in a variety of directions. This wayward growth pattern gives these trees character and a unique look, so don’t expect to prune or shape it into the look of a conventional conifer.
In addition, these trees often retain their dead lower limbs for an extended period of time. You can lop them off, but it’s often not necessary to do so. If you do decide to clean up the lower extremities of your jack pine tree, do so in the spring before the sap starts running in the summer season.