Normal Spacing When Planting White Pine Trees
The ideal spacing when planting white pine trees (Pinus strobus, USDA zones 3-8) is 20 feet, but this recommendation can vary, depending on cultivar and whether you're growing trees as landscape specimens or en masse for timber. White pines are fast-growing trees with soft needles and a blue-green color. These long-lived trees survive from 200 to an estimated 450 years.
Tip
Space white pine trees at least 20 feet apart when growing as landscape specimens, although the cultivar and intended use for the trees can affect the proper spacing.
Use Considerations for Spacing
Spacing when planting white pine trees depends upon the planned use for the trees. You may plant white pines as ornamentals, as part of a windbreak, to form a screen or for lumber. How you plant the pine trees affects their shape and growth habit. In stands, white pines tend to branch only along the upper portion of their trunks; trees grown with space around them or in the open create branches further down their trunks.
Spacing for White Pine Trees
As a general rule, leave 20 feet between white pine trees in your yard. If you're growing the trees for timber, however, a common recommendation is planting 600 to 1,000 trees per acre for timber. This translates to a much closer spacing of 6 feet by 6 feet or 8-by-8-foot spacing. For windbreaks, plant white pines in a double or triple row, leaving 15 feet between the rows.
In some cases, spacing will be affected by the cultivar you select. Cultivars of white pine vary in their form from rounded to upright. Some have drooping branches. 'Nana' is a dwarf cultivar that reaches a mature height of only 6 to 8 feet with a 10-foot width, so you can plant multiple cultivars with an 8- to 10-foot spacing, which is much closer than the species recommendation. Keep in mind that white pine trees rarely grow in homogenous stands, and a mixture of trees that preserves the plant diversity in an area is better for wildlife.
Considerations for White Pines
White pines are not suitable trees for foundation plantings because of the height and spread of the mature trees, which reach 20 to 40 feet wide and 50 to 80 feet tall, with a maximum potential height in excess of 150 feet. White pines make a poor choice for urban locations, as the trees do not tolerate salts or air pollutants well.
White Pine Growing Conditions
White pine trees are deep-rooted and perform well on sandy, loam, sandy loam and clay loam soils. White pines outperform nearby hardwoods on sands. The trees grow in excess of 2 feet per year, on average. Under canopy, growth may be limited to 6 inches per year, but unimpeded, the trees can grow more than 4 feet per year and will reach a larger diameter.
Plant your trees in late winter to early spring, while they are dormant. Select a site that provides full sun and a moist, well-draining soil. Dig a hole at the desired location using a shovel. Use a tape measure to determine the spacing for additional trees. While some white pines tolerate poorly drained soils, Eastern white pines are intolerant of drought, standing water and wet soil. You must prepare the soil by turning it, and remove nearby plant competition to give white pines a proper start.