Gardeners love clematis for its ornamental beauty and easy-growing attitude. Hardy up to USDA zone 3, once planted in the garden, clematis will grow well on its own for up to 25 years. If you wish to start a new stand of clematis, or experiment with new cultivars, the plant can be grown from seed. For the best results, plant fresh clematis seed right after it is collected in fall. And then be patient. Clematis seed is slow to germinate. It may take up to three years for some seed to germinate although most will sprout within six months to a year.
Fill a 4-inch pot with a moistened soil-less seed-starting mix.
Place three to four clematis seeds, 1/2 inch apart in the center of the pot.
Press the seeds into the medium with your finger to ensure good contact.
Cover the seeds with a thin layer of horticultural sand.
Place a plastic freezer bag over the container and secure it with a rubberband around the rim of the container.
Place the pot in a shaded spot outdoors for the duration of the winter if you live in a climate with freezing or periodically freezing winters (USDA growing zones 4 through 8). The freeze/thaw cycle will help to break the seed’s dormancy. If you live in a warmer climate, place the pot in the refrigerator until spring. Whether outside or inside, check the soil’s moisture level at least once weekly. Lift the bag, touch the soil with your finger and make sure it is still moist. If it is not, re-moisten (never soak) the soil with water from a spray bottle.
Bring the pot indoors in spring. Check the soil’s moisture level weekly and keep the bag in place.
Remove the plastic bag once the seed germinates. Keep the soil moist with regular watering with a watering can.
If you plant too many clematis seeds, you may use a planting flat instead of a pot. Transplant the germinated seed into a 4-inch pot once they grow two true leaves.
If the seed still has not germinated by next winter, place it outdoors or in the refrigerator for the duration.