"The Coast Douglas Fir reaches maturity and begins producing cones at 12 to 15 years old. The male cones are usually about 2 centimeters long and are a yellow or dark red color. The female cones are a bit larger at about 3 centimeters long and are green or dark red in color. The female cones have large bracts and can start pollination soon after they develop. By mid-September the cones have fully matured and the seeds have ripened. The mature cones are then 8 to 10 centimeters in size and the bracts turn brown once the seed is also mature. Once cone maturity is reached seed fall begins. By the end of October 2/3 of the total amount of seeds have fallen and by the following spring the rest of the seeds will have fallen. The number of cones produced each year is dependent on numerous variables. It depends heavily on the number of primordia that develop into actual buds. Harsh frosts and insects are also responsible for destroying the seed cones before they reach maturity. Older trees have the advantage of producing more cones then the younger ones. ." Quote from - http://bioweb.uwlax.edu/bio203/s2009/cook_morg/Reproduction.htm