Douglas firs, which come from North America, can be found in many forests and parks. Here you can harvest seeds from the cones in August and September. In order to germinate, however, they must undergo special treatment before sowing.
How do I stratify Douglas fir seeds?
To stratify Douglas fir seeds, they require a cold stimulus. They are sown outdoors in late autumn and exposed to the cold in winter. For refrigerator stratification, store the seeds with potting soil in a sealed bag at 2-3°C for two to three weeks.
Why do Douglas fir seeds need to be stratified?
The Douglas firis one of the cold germinatorsand itsseeds require aweek-longcold stimulus,to to be able to rise at all. When freshly harvested, they are in a state of dormancy caused by germination-inhibiting substances, which must be overcome.
This rest period prevents the Douglas firs from germinating in the fall and dying off again in the frosty period of winter. During the cold period, which can also be artificially recreated (stratification), the germ-inhibiting substances are slowly broken down.
When is the best time to stratify Douglas fir seeds?
Either leave the seedsoutdoors during the cold winter months or break seed dormancy by storing the seeds in the refrigerator for a while.
How are Douglas fir seeds stratified outdoors?
SowingSimply plant the Douglas firsin the bed in late autumn. Alternatively, you can fill growing trays with substrate and place them in the garden during the winter.
Since the Douglas fir is a light germinator, germination occurs above ground through the stimulus of light. Therefore, cover the seeds with a very thin layer of soil.
How to stratify Douglas fir seeds in the refrigerator?
For this, theseeds are stored in the refrigerator for a few weeks and then sown:
- Put some Douglas fir seeds in a freezer bag into which you have previously filled some potting soil.
- Seal the bag tightly and store it at two to three degrees for at least two weeks. This temperature is usually reached directly above the vegetable compartment.
- Sow in seed trays, place in a bright, sunny place and keep evenly moist.
Tip
Young Douglas firs require intensive care
The small seedlings are very sensitive and require a lot of attention in the first few years. Keep the trees, which should preferably be in partial shade, moist, but at the same time avoid waterlogging. In addition, the freshly germinated Douglas firs must be protected from severe frosts and frost drying.
