The seeds of a clematis are cold germinators. In order to get in the mood to germinate, stratification is essential before sowing. You can find out how this procedure works and how the cotyledons are coaxed out here.
How to prepare clematis seeds for sowing?
Clematis seeds require stratification by storing them in a moist peat-sand mixture in the vegetable compartment of the refrigerator for 6-8 weeks. The germinating seeds can then be planted in seed pots with special sowing soil.
How does clematis seed stratification work?
Stratification refers to a wet-cold treatment that simulates winter weather conditions for the seeds of a clematis. Mother Nature provides the seeds with a germination inhibitor so that they do not sprout in the middle of winter. Only when they experience a cold stimulus do the cotyledons break through the seed coat. The process can be easily carried out using a refrigerator. Here's how to do it:
- Spread a mix of peat and sand on cling film and spray with water
- Spread the clematis seeds on top
- Twist the foil into a roll and tie tightly at the ends
- Place in the vegetable drawer of the fridge for 6-8 weeks
During the course of stratification, the moisture content of the substrate is checked every few days, because germination does not occur in dry soil. Germinating seeds are sorted out and sown in the classic way.
Stratification in the field – this is how it works
If you want to avoid the siege of the refrigerator with seeds from a clematis, this alternative for propagation by sowing is ideal:
- Small cultivation pots fill with peat sand (€13.00 on Amazon), herb soil or commercially available sowing soil
- Place one seed in each pot on the moistened substrate and sift over it to a height of 3-5 mm
- Put a glass or a transparent cap over each seed and carry the seed containers outside
- Place in a partially shaded, sheltered spot throughout the winter
While the seeds go through the cold cycle, the glass hood is ventilated daily to prevent mold from forming. Regular watering is also mandatory so that the soil does not dry out. If these are the seeds of a wild species, you can usually look forward to the first seedlings next spring.
Tips & Tricks
Since the germination of seeds from clematis hybrids can take up to 3 years, meticulous cleanliness is the top priority for a successful process. Therefore, disinfect not only all equipment and tools, but also the substrate. This can be done in the oven at 150 degrees within 30 minutes or in the microwave at 800 watts within 10 minutes.