Douglasias are imposing trees that require a lot of space. If you have the space and want to propagate your Douglas fir, you can use the seeds.
Douglas fir trees are often found in our forests and the evergreen conifers from North America are also a welcome guest in parks and gardens. If you can offer enough space for the plants on your property, you might even think about propagating the Douglas fir in order to get a second tree or even a small grove. You can read here how Douglas firs can be propagated and what needs to be considered.
How to propagate Douglas firs?
Douglasias can be propagated by seeds. If you already have a Douglas fir, you can harvest the seed and use it for direct propagation.
When can the seeds be obtained?
Douglas fir seed maturity depends on several factors:
→ Location
→ Climate
→ general weather conditions
The seeds can usually be expected to ripen in August and September. If you are unsure, you can cut open a cone and see if the seeds have already changed color. If the cones and the seeds turn brown, it can be assumed that the seeds are mature and can be used to grow new plants.
» Tip: The seeds are easier to harvest in dry weather.
What needs to be considered beforehand?
Careful preparation of the seedbed is necessary before the seeds can be planted in the ground. The seedlings are sensitive and make high demands on the soil. It is important to ensure that the soil is well drained. The young plants cannot develop in a substrate that is too firm and too heavy. Heavy soil can be made more permeable by adding sand or gravel.
It is also particularly important to keep an eye on the soil's water balance. Humidity is a big issue for the Douglas fir. It is important to rule out dryness as well as waterlogging. The soil should not dry out and, on the other hand, must not be too damp. This introduces the hobby gardenersome plant care challenges.
In order to be sure that the soil quality meets the requirements of the seedlings, it is advisable to determine the pH value of the soil. Any hobby gardener can do this themselves. Corresponding sets are available for a few euros in every garden center or on Amazon:
» Tip: If the pH value is between 5 and 6.5, the substrate is suitable for growing the Douglas fir.
It is also important for the substrate that it is as low in lime as possible.
When can you sow?
The best time for sowing is early May. Depending on the weather and location, it is necessary to wait until no more night frosts are to be expected.
What to do with the seeds?
Once the seeds are harvested, they cannot be planted immediately. If you don't want to put the seeds in the seedbed outdoors in spring, you can get a little head start by growing them indoors and transplant the early trees directly next year.
The Douglas fir is a cold germ. The seeds will not germinate on their own if sown immediately after maturity. The seeds contain substances that inhibit germination. The ability to germinate is activated when the seeds are stored in the refrigerator at around three degrees for about two weeks. Before sowing, after the cold shock, the seeds are placed in a jar filled with water for a day and kept at room temperature.
Use a shallow seed container and fill it with potting soil. Seeds are only lightly covered with substrate, placed at room temperature and consistently moisturized.
Propagation of Douglas fir - step by step
➊ Collect seeds
➋ Store seeds in the refrigerator for about 14 days
➌ Water seeds
➍ Spread seeds in planter
➎ Cover seeds thinly with soil
➏ Keep seeds moist
To accelerate germination, it generally makes sense to cover the planter with a film cover. This creates a microclimate conducive to germination. It should not be forgotten to air the cover for a short time every day so that no mold can form due to the build-up of air. The planter is set up brightly at room temperature and watered evenly.
» Tip: In order to be able to dose the moisture well and not to let too much water get to the seeds, watering can be carried out using a plant sprayer.
What about thePropagation of the young plants?
Young plants are particularly sensitive. If you have grown the Douglas firs indoors, it will be time to plant them outdoors next spring. First find a suitable location for the plant. The little seedling will grow surprisingly fast, indicating that there should be enough space - right from the start. Plants don't like being transplanted. Therefore, plant the young plant in its intended location and prepare the soil accordingly so that it is permeable and the roots can grow well.
When planting, make sure you keep a sufficient distance from buildings and roads. As a rule of thumb, the planting distance should be identical to the expected growth height of the tree. Bear in mind that the Douglas fir in Europe can grow more than 50 meters high. This makes it clear that this plant is not suitable for every garden.
» Tip: By choosing the right location, you ensure the development of the plant and avoid later felling.
Characteristics of young Douglas firs at a glance
- prefers partial shade
- proves to be highly competitive
- requires permeable soil
- is very susceptible to frost when young
- sensitive to waterlogging
Problem child Douglas fir
Douglas fir requires far more care and attention when young than older plants. Up to the age of about twelve years, the plants are particularly sensitive to frost. In late winter in particular, there is a risk that the needles will begin to open on sunny days and water will evaporate, which the still frozen trunk cannot supply quickly enough. This causes the needles to become red and dry.
» Tip: There is usually no major damage and the buds sprout as usual.
Young Douglas firs are also particularly susceptible to drought and prolonged periods of sunshine. The probability of desiccation is high. Immediately after planting, ensure daily watering. Only about a month after planting has the water balance largely returned to normal and the roots have regenerated.
» Tip: Young Douglas firs require far more care than other tree species.