Clematis jackmanii is one of the easiest of all clematis to grow. It grows 10 to 20 feet tall and puts on a show of 4-inch, dark, violet-purple, abundant flowers in mid-summer. Jackmanii is one of the oldest selections of clematis hybrids, discovered in 1863 by clematis hybridizers George Jackman and his son, George Jackman II. Like all clematis, jackmanii likes to grow in sun or part-shade, in deep soil rich in organic matter. All clematis are classified according to their pruning group — 1, 2 or 3. Jackmanii belongs to pruning group 3, the simplest of all pruning groups.
things you’ll need:
- Disconnect and unwind all the old foliage from the support on which the clematis is growing, removing any ties that may be in use. You can snip these stems off at 3 to 4 feet from the ground just to make the rest of the task easier to manage.
- Locate the second set of buds on the stems that are coming up from the base of the plant, and cut just above the bud. Sometimes there will be stems with no buds on them. If you cut into them and see only brown in the center of the stem, they are dead stems. Cut them all the way to the ground. Any stems with green on the inside are alive, even if they may appear dead from the outside.
- Fertilize around the base of the plant with a fertilizer high in phosphorous and designed for tomatoes or roses. Clematis are heavy feeders and will perform better with proper nutrients.
- Bark mulch keeps moisture in and weeds out.
Cover with 2 inches of finely shredded bark mulch to help keep moisture in and weeds out. Be sure the mulch does not touch the stems.
Tips & Warnings
Jackmanii is pronounced jack-mah-nee-eye.
Prune the plant anytime in winter while it is dormant or in early spring before it has started to emerge. The later in the spring season you prune, the easier it will be to identify healthy buds. Do not prune too late, or energy will be diverted to the upper part of the plant that will be cut down.