Clematis can produce vibrant blooms for decades
Clematis was first cultivated in Japan for many centuries and in the 16th Century moved to Europe, especially to the countries of Britain, France and Belgium. Clematis finally arrived in the United States toward the end of the 19th century. Today there are more than 400 cultivars of clematis to choose from, and even the smallest garden can support one or more varieties of these massive blooming plants.
Clematis are divided into three pruning groups, called pruning group 1, 2 and 3. Pruning group 1 are almost entirely in Zone 6 and up, and not hardy for this area. They do not die back to the ground in the winter, and bloom most of the year. Pruning group 2, are almost entirely in Zone 4 and up, which are also not hardy in our Zone 3 area. In late April and early May these need pruning down to a pair of strong buds, however, much of the plant remains after pruning. They bloom on their "old" wood in early spring and their "new" wood (this years growth) in the summer.
Pruning group 3 begins to bloom slightly later and only on "new" wood stems that have grown this year. Group 3 are the type of clematis that grows vigorous here in Zone 3 blooming continuous from mid- to late-summer. Group 3 needs to be pruned in late April or early May. Cut the entire plant back to about 6-12 inches above the ground leaving 2 sets of strong buds on each stem. The dead stems from the previous year are a tangled mass and all need to be removed.
Before you buy your clematis, decide where you are going to plant it. Clematis develop a very long tap root and should not be moved. Good drainage is essential for the clematis deep root system. Dig a hole 18 -24 inches deep and 18 inches wide. Cover the bottom with a good rich compost or well-rotted manure and peat moss. Bone meal or bulb food may also be added and will promote good root development. Add enough topsoil to cover the compost, peat moss mixture. When you plant the clematis remove a few of the lower leaves. Plant the crown 4-8 inches below the soil surface. Wherever there is a leaf removed from the stem a root will grown down into the soil. Deep planting encourages "new" shoots to develop along the stem. Water the plant well and mulch the soil surface to keep the roots cool and moist. The old saying "sun on their head and shade on their feet" is true with clematis. It is fine to plant a small shrub or plant in front of the clematis to provide shade for its root. However, remember to plant this far enough from the base of the clematis to allow for the mature growth of that shrub or plant. It is very important that you provide a trellis, arbor, or some type of support for the clematis to climb. Clematis climb by twisting their leaf petioles around the support you provide. They like wire, and other fine objects, anything that is more than three-quarters of an inch may be too large for them to attach to easily.
A clematis is a heavy feeder because it produces such an abundance of blossoms. So it is important that you feed it on a regular schedule with a bloom booster fertilizer as long as it is producing blossoms. It is well worth the extra effort you put into planting and caring for your clematis because they will last for several decades. There are reports of some 80-year-old clematis that are still blooming marvelously.
Kyle Schulz is a Wadena County Master Gardener from Sebeka, and the regular gardening columnist for the Wadena Pioneer Journal.