How to plant white pines
What to plant
A variety of planting materials are available.
- Seedlings grown from seed collected in Minnesota may be better adapted
to local conditions than seedlings from seed collected in other states.
Verify the seed source with your grower.
- Container stock, bare-root seedlings, bareroot transplants or even
larger trees can be selected. Being larger, bareroot transplants, may survive
better when planted in the shade of an overstory canopy.
- Currently, there are no sources of planting stock proven to be resistant
to white pine blister rust. Seedlings advertised as "resistant"
may cost more and have no proven benefit.
Although white pine seedlings can do well in partial shade of overstory
trees, they can be choked out by the shade of competing grasses, weeds
and shrubs. These
plants can be controlled or killed prior to planting by hand cutting, herbicides
or scarification of the patches where the seedlings will be planted. A
recent innovation is to use a "weed control" mat for each seedling.
It inhibits weed and grass growth immediately around the planted seedling.
The mat may be made out of a variety of materials including mulch, cardboard,
jute or polypropylene. It should be about three feet in diameter. Solid
materials need to be weighed down with soil or rocks and a few holes poked
through them to allow water to soak through.
Additional site preparation and tending work may be done to improve seedling
and sapling survival. Since blister rust needs both the white pine and
the Ribes to
complete its life cycle, getting rid of the Ribes breaks the life cycle
and therefore prevents blister rust infections. To prevent or minimize
white pine blister rust infections, Ribes ( currants and gooseberries)
could be eliminated in and around high value plantings. Ribes are most
easily identified in the early spring. 1. The effectiveness of Ribes eradication
varies by location. It's most effective in Hazard Zone 1 and least effective
in Zone 4. (See map in Site Selection.) If time and energy permits, eradicate
Ribes in a buffer around the planting area, too. In Hazard Zone 1, eradicate
Ribes in a 50 foot buffer, in Zone 2 = 70 feet, Zone 3 = 600 feet, and
Zone 4 = 900 feet. 2. Pull up or treat all the Ribes species in the planting
area. This should be done prior to planting and again two or three more
times at three year intervals in order to get rid of the plants germinating
from seed stored in the soil. 3. Don't plant gooseberries and currants
near high value plantings of white pine.
When to plant
Spring is usually the best time to plant white pine. Soil moisture
is usually good and cooler conditions help prevent drying of the young
seedlings. In southern Minnesota, planting season is from early April to
early May, whereas, in northern Minnesota, the season is late April to
Handling and storage of seedlings
Due to root desiccation, white pine seedlings may die before they even
get their roots in the ground. Care must be taken so that young, bareroot
seedlings are kept cool and moist right up until the time they are planted.
When you receive your tree seedlings, check to make sure the roots are
moist. If they are especially dry and crackly, return them to the nursery.
If they are somewhat dry, wet them down and try to plant them as quickly
as possible. If you need to store them for a few days before planting,
keep them inside the package they were shipped in, find a cool, well shaded
spot and allow for a limited amount of air circulation around the package.
The sooner you plant them, the better their chances of survival. During
the planting process, make sure the tree roots are kept moist and are not
expose to long periods of sunlight or drying winds. Even a few minutes
of exposure to a light breeze on a sunny day will kill the roots ( and
White pine seedlings can easily be planted using a shovel, hoedad or
planting bar. Always plant in mineral soil, not in the duff or litter layer.
Tree planting machines can be used for open field plantings, especially
in southern Minnesota, where the
risk of blister rust and weevil are low. 1. Make sure the hole is deep
and wide enough to allow the roots to fully extend down and out to the
side. Roots should assume a natural position and not be twisted, compacted
or stick out of the hole. 2. Plant the seedling at the same depth it grew
in the nursery. If planted too deep, roots will become curled and the seedling
is more likely to be killed by insects and diseases. If planted too shallow,
some roots will be exposed to the air and they will die. 3. Refill the
hole with soil and pack the soil firmly around the root system. Avoid creating
air pockets around the roots, creating a mound or depression near the stem
or allowing large amounts of organic matter to be incorporated into the