The Clematis can be successfully grown as long as a few basic needs are met. It prefers a rich, well drained soil and a neutral PH. Our Pacific Northwest soils tend to be high acid. To sweeten the soil to a neutral level, add one handful of ground limestone to the hole before planting.
Most Clematis enjoys a sunny location with a root system that is cool and moist. To achieve this, plant the Clematis near a ground cover or some shrubbery.
Make sure it is in a sheltered area away from most wind and provide some kind of support for it to grow on. The Clematis will reach lengths of 12 to 20 feet.
A strong crown will develop if the Clematis is placed in the ground, a couple of inches below the old soil line on the plant.
Deep planting often prevents the Clematis from dying due to Wilt disease. Wilt fungus attacks at the soil surface and kills the plant tissues above ground.
Consider planting Clematis with a climbing rose. Both appreciate the same soil conditions and the rose will usually outgrow the strangling ways of the Clematis.
Many of our popular varieties were brought out 60 to 100 years ago, so the Clematis is not a ‘new’ plant.
Here are some small flowered varieties: Minuet, Venosa Violacea, Etoile Violette, Little Nell, Alba Luxurians, and Abundance. They flower from July until September and may be pruned to the crown after bloom.
C. cirrhosa balearica and Marie Boisselot enjoy a shaded north wall. If you have a Clematis that isn’t blooming, it may be planted in too shady of a location.
Spring flowering varieties need no regular pruning. Pruning should be done after flowering to remove dean wood and to shape the plant. Doing this will eliminate a ‘bird’s nest’ effect. Pruning now will provide ample time for the flower buds to develop for next spring’s show. Clematis armandii, C. macropetala, C. alpine, and C. Montana are all spring flowering varieties.
For varieties that start blooming in the middle of June, pruning should be done in late winter. A thick woody stump, not more than one foot high will result. If you want this type of Clematis to cover the side of a wall or a tree, pruning need not be so severe. Some varieties from this category are Victoria, Star of India, Jackmanii, Perle d’Azur, Comtesse de’ Bouchard, and Lady Betty Balfour. They are all hybrid varieties. Some species varieties classified under this bloom time and pruning conditions are C. flammula, C. Campaniflora, C. Viticilla, C. tangutica, and C. orientalis. All the above mentioned varieties flower on the tips of new shoots made in the current season. These shoots can be from 3 to 12 feet long.
Lastly, is a group of Clematis that flower on short, lateral growth made in the previous season. These are all hybrids and they will have large flowers between mid-May and mid-June. Examples are Lady Northcliffe, The President, Nellie Mosier, William Kennett, Lord Nevill and Belle of Woking. Prune only dead wood, After pruning, support the plants framework on a trellis for best display.
©1987 Cindy Morgan Permission to reprint – must include credit to author and link to web page. https://cynthiamorgan.wordpress.com/