Answer: Clematis is a hardy perennial and can be planted in early spring as a dormant bare-root plant or at any time if it is container grown. I would be concerned however about trying to grow it in a container. This plant requires a cool, evenly moist yet well drained soil and it may be difficult to maintain that degree of temperature and even moisture in a container. The vine is also a large plant and to allow for room for its roots does best planted in the soil. Planting it in the soil will also insulate the roots during the winter and enable it to survive the coldest temperatures with less stress. If you try to grow it in a container, make it as large as possible -- a half barrel would be preferable.
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