Tall, Taller, Tallest. Douglas fir can grow to 200 or 300 feet in the wild, providing food and nesting areas for wildlife, including grouse, nuthatches, warblers, squirrels and chipmunks. A cultivated tree never achieves the same height or grandeur. In your yard, a Douglas fir will only grow 40 to 60 feet tall. Experts at Cal Poly estimate the growth rate of Douglas fir at 24 inches a year, but this also depends on its growing conditions.