Yes, clematis can be started by laying down a vine onto the soil, covering part of the stem with compost or damp soil, and letting the end continue to grow above ground. By the end of the summer the segment under the soil will have grown roots. You can speed this along by removing the leaves that will be underground. This technique is called layering and it works with many woody shrubs such as rhododendron and azaleas as well. Keep growing, Marianne Binetti