| Basic Info on Douglas Fir | ||
|---|---|---|
| Species | Size | Basic Requirements |
| Douglas Fir (Pseudotsuga menzieisii) | Height 40 to 80’ | Zones 4 through 6; Full sun and part shade, acid soil, no clay |
| Spread 12 to 20’ | ||
Douglas firs grow from 75 to over 100 feet tall at maturity, although in a landscape they tend to be smaller. Typically, their branches spread to about 1/3rd their height as they grow. When young, they grow 1 to 2 feet a year, reaching about 15 feet in their first 10 years, and then growth slows as they age. Their youthful stiff horizontal branches are dense, but they open up and become less attractive with increasing age.
Douglas fir foliage is evergreen throughout the winter. The leaves are actually flat needles with round tips about 1 or 1 1/2 inches long. They grow individually, spiraling around the length of the stems. Dark green or bluish-green on top, they are paler underneath with two white lines running the length of their undersides. They have a distinctive camphor-like odor when crushed.
Male and female flowers both grow on the same tree. They appear in late April or early May as bright red cylinder-shaped cones on year old wood. Unlike other firs, Douglas fir cones hang down. The fruit appears near the top of the tree as 3 or 4-inch cones, distinguished by the extended tips on each of the cone's scales which resemble whiskers. They are green, but turn brown as they mature toward August. Many stay on the tree through the winter, but those that fall to the ground are relished by songbirds, small animals like squirrels and chipmunks, and even deer.
Choices of Douglas Fir
Glauca from the Rocky Mountains is a bit slower growing, is more blue-green and hardier, commonly used for Christmas trees and most suited to the East. Glauca pendula has droopier branches. Fastigiata is very tall and straight. Viridis from the Pacific coast is less cold hardy. Lincoln from New Mexico is resistant to gypsy moths.
