Growth Rate

• The Douglas fir tree is classified as growing at a medium rate denoting a tree that grows between 13 and 24 inches annually, according to the Arbor Day Foundation. The Douglas fir's average terminal growth rate sees the tree mature to a height of between 40 and 70 feet with a spread of 12 to 20 feet. Endowed with a pyramidal shape and a straight trunk, the tree grows in excess of 100 feet in the wild.
  
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Hardiness Zones

• The Douglas fir thrives best in U.S. Department of Agriculture plant hardiness zones 4 through 6, which encompass the country's colder, Northern locales. The average terminal growth rates are negatively affected when grown in a hot or humid climate. This evergreen specimen with bluish-green needles that occasionally take on a yellowish-green hue appreciates a mixture of full sunshine and partial shade.
  
  

Soil

• Moist, well-draining, acidic or neutral soil is its preferred home, although different species achieve better health in their ideal growing zone. The Coast Douglas fir demands a deeper, richer soil than does the Rocky Mountain Douglas fir, a species that grows nicely in the rockier earth of mountain slopes. Neither specimen tolerates especially dry soil, nor the tree is prone to breakage on the side frequently buffeted by high winds.
  
  

Altitude

• Producing cones of between 3 and 4 inches in length, the average terminal growth rate is affected by the altitude. In mountainous terrain, the tree normally exists in pure stands at an elevation of between 5,000 and 8,000 feet. The Douglas fir produces a wood that is tan or reddish in color and fine-grained, making it an excellent wood for lumber.