A clematis vine can climb high in your garden – Chicago Tribune
Several species of jasmine are vigorous, long-lived perennial vines that thrive in the upper Midwest. “Some of them thrive so well that pruning is in order,” said Spencer Campbell, director of the plant clinic at Morton Arboretum in Lisle.
The most popular clematis flowers are the large purple saucers of Jackman’s clematis, a common summer sight in Chicago area gardens. “Jackman’s clematis hybrids are what usually comes to mind when the word clematis is mentioned,” Campbell said.
A Jackman’s clematis (Clematis x jackmanii) was planted to climb the massive central tree in The Arboretum’s The Gerard T. Donnelly Grand Garden, and by mid-June some of the plants had risen more than 6 feet. There are Jackman clematis hybrids that bloom in pink, red, and blue, as well as purple. In fall, the delicate seed heads are also decorative.
“Jackman prefers clematis, but there are other varieties that need full sun,” Campbell said. All clematis like well-drained soil that contains plenty of organic matter. They prefer cooling their roots with an insulating layer of mulch, and often grow well with their roots shaded by other plants. “Cold feet, face in the sun” is a proverb often applied to growing jasmine plants.
Although some cultivars (cultivated varieties) have been bred to remain relatively small for containers, most clematis need space and something to climb. It can often reach 10 to 20 feet if left unpruned.
Clematis vine climbs by wrapping its leaves around everything it encounters as it grows. The vine does not need to be tied to a support like a climbing rose. “He may need a little guidance so he only climbs what you want him to climb,” Campbell said.
Jasmine will weave the stems of the shrub, and the combination of jasmine and roses is a classic English garden. In general, leaf stems need something narrower than a finger to wrap around them. A wire tower filled with clematis can increase the height of perennials.
If you prune your jasmine vine to keep it under control, timing is important. “Pruning at the wrong time could mean you cut off flower buds,” Campbell said.
Some species and varieties thrive on newwood, which is the new stems that have emerged this year. Others thrive on old wood, meaning they develop flower buds in late summer or fall and carry them through the winter. “Read the plant label carefully when purchasing a clematis plant so you know whether to prune it in winter or late summer,” he said.
There are about 300 species of jasmine plants worldwide, including a few that are native to North America. Here are some lesser-known species of clematis that grow well in Midwestern gardens.
Durand clematis (Clematis x Durandi): Somewhat smaller than Jackman’s clematis, this hybrid has blue cornflower flowers that start out urn-shaped and open to saucers.
Scarlet clematis (Clematis): Although native to Texas, this species is hardy in the Chicago area. Its urn-shaped flowers are a hot, lively pink color.
Maiden’s hut (Jasmine virginia): Native to eastern North America, including the Chicago area, this species has masses of small, fragrant white flowers in late summer. It may require pruning to control its growth.
Italian clematis (Jasmine Vitesella): The lavender or purple flowers of this vine are shaped like hanging bells.
Jasmine in sweet autumn (Clematis): This species is not native to Asia. It is an aggressive grower that reseeds easily, and can quickly escape into nearby landscapes, including natural areas. “We don’t advise gardeners to grow it,” Campbell said. “If you already have some, you should consider replacing them with a local alternative like a maiden hut.”
For advice on trees and plants, contact the Plant Clinic at The Morton Arboretum (630-719-2424, mortonarb.org/plant-clinicor firstname.lastname@example.org). Beth Potts is a staff writer at The Arboretum.