Clematis

Jul 22, 2010

by Margaret Inwood, Lanark County Master Gardeners

Clematis can be grown in a variety of settings from shade to full sun. Choose a spot where the roots will remain cool. Clematis climb by twining their stems around a support structure such as wire, trellis or netting. Dig a good size hole and refill it halfway with mixed topsoil, plenty of organic matter such a compost, well-aged manure and/or peat moss. Add half a cup of 5-10-10 fertilizer and if your soil is acid, add a little lime. Place plant in hole and refill around it. Make sure that the crown (the spot where the stem meets the roots) is covered with 2 inches of soil, firm and water it. To help keep the roots cool, place several inches of composted leaf mold or other organic matter in a one-foot circle around the plant. Clematis should never be allowed to dry out, so water regularly in dry spells. Once the vine is growing, feed it with a fertilizer such as 5-10-5.

How much you should prune a clematis depends on when the plant blooms. Varieties that bloom from mid-June to fall should be pruned back to 15 inches starting in their second spring, just as the buds begin to swell. This may seem drastic, but summer bloomers flower only on current year’s growth, so removing the previous year’s wood results in more flowers and a stockier plant. Some clematis varieties bloom between early May and mid-June on old growth, and often again in fall on new growth. In order to encourage a good display during both seasons, prune this type of clematis lightly in early spring, removing only stems that are dead and cutting back weak ones. If you are unsure of which type of clematis you have, let the vine grow freely for a year and observe its blooming and growth patterns.

All your gardening questions can be submitted and answered at www.lanarkmastergardeners.mgoi.ca