Certified GKH Gardening Expert
Germination is spread out, with some germinating after a few weeks and some taking up to 8 months.
Some clematis species have seeds that require cold stratification before they will germinate. This means you will either plant the seeds in fall so they experience winter cold, or place them in a plastic bag with a moist paper towel and then place that in the refrigerator (in the dark) for two months.
After the stratification period, for seeds you will grow indoors, take them out of the fridge and keep them in a dark, warm place inside the baggy until they start to germinate. Keep the towel moist during this time.