Answer: Clematis hirsutissimus is hardy outdoors to zone 4 so it should be fine outdoors in your garden. If the plant has not rooted or grown, it is struggling with its environment. This clematis will grow in full sun to part shade, in average, well draining soil. You might try repotting it in fresh potting soil if it is still in a container, or try planting it directly in the ground. If it's already in the ground, you may want to dig it up, amend the planting bed with organic matter, then replant. Anything you can do to make the soil more hospitable shown make a big difference in its growth.
Best wishes with your garden!
Q&A Library Searching Tips