Life Cycle and Reproduction


                                        ReproduCoast Douglas Fir needlesction Timeline:

The full reproductive cycle of the Coast Douglas Fir takes about 17 months to complete, beginning in early April and eventually ending in late September of the next year. During this reproductive cycle both sexual and asexual reproduction are taking place. The Coast Douglas Fir is also monoecious or hermaphroditic meaning it contains both the male and female parts necessary for reporducation to take place, all within the same plant.

1. Seasonal growth starts in April with the beginning of bud growth.

2. During May and June the buds grow and burst, forming the bud primordia.

3. From July to November the leaf, bract and microsporophyll begin to immerge.

4. Once March hits again, meiosis begins to take place and the pollen starts to develop.

5. In April the cone buds finally flower and the pollination of the seed cones takes place.

6. During May and June fertilization takes place and the seed cones grow at a rapid pace.

7. From August to September the embryo and the seeds are developing.

8. By late September the cones have matured and they shed their seeds.


ConesDouglas Fir Cone

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 areCoast Douglas Fir cone buds 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.






The seed size is determined before fertilization even takes place, but there is little variation in seed size coming from one tree. Germination of the seeds takes place from mid-March to early April, but during the first year the seed growth occurs at a very slow pace. Due to the high amounts of moisture the seed growth is halted in midsummer until April of the following year. The ideal conditions for seed germination consist of moist, mineral rich soil. During the first year the seedling prefer light shade, but as they get older they need full sunlight. Much like the cones, the seedlings have factors that can affect their numbers including being eaten by insects, birds or other animals, competing with other plant species for resources and land, or having to deal with inadequate environmental conditions. Regeneration also depends on the amount of competition with other species, as well as on weed control.















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