Tending white pine
Maintaining good growth and survival will likely require control of competing weeds and shrubs and management of the overstory (if present).
Control Competing Vegetation
Grasses and weeds can be controlled through mowing or mulching, or the use of individual "weed control" mats. The goal is to maintain an area about 3 feet in diameter around the trees that is relatively free of weeds and grasses. Larger plantings may require the use of herbicides. Consult with a forester or other professional on the kinds, timing, and applications methods best suited for your situation. Shrubs can be controlled through hand cutting or herbicides.
The shade from overstory trees should be maintained at about 40 to 60 percent (the percentage of the area where direct sunlight hits the ground). If shade is or becomes too dense, partial overstory release may be necessary. This can be done through the careful selection and removal of some of the overstory trees. Overstory trees can be cut down or girdled (killed and left standing). Girdling kills the tree, but maintains it within the stand for many years, providing excellent bird habitat.
White pine buds are a favorite food of deer, and may need some protection to deter deer browsing. This can be done through the use of bud caps. A bud cap is simply a piece of paper wrapped and stapled around the terminal leader and bud of the tree. This protects the terminal bud from deer, yet allows the tree to grow up through the paper during the next growing season. Browsing of lateral (side) branches and buds is usually not detrimental to the health and survival of young white pine.
Bud capping should be done in the fall, before snow covers the ground. Lightweight paper cut into 4" x 6" pieces works well. Fold the paper in half around the leader to form a sleeve that covers the terminal bud. Staple the paper together using at least three staples, and catching some needles to help hold the paper in place. Reapply bud caps every year until the tree is at least 4 feet tall and out of easy reach of deer.
Careful pruning of white pine limbs helps reduce damage from blister rust and white pine weevil. It also helps trees grow straighter and produce higher quality wood products. Removal of needles and branches slow the trees's growth, so make certain not to remove too many branches at any one time. To maintain adequate growth, leave two-thirds of the trees' height with branches. Never remove more than one-third of the crown. When pruning:
- Use a pruning shears or pruning saw (chain saws are not recommended).
- Do not cut the limbs off flush with the trunk or leave branch stubs (see diagram below).
- Prune during the tree's dormant season (fall, winter).
Continue pruning to a minimum height of 9 feet (to 17 feet for lumber production).