Answer: Here's some information on growing clematis:
Clematis vines always want their roots shaded, and the plant growing up into full sun. That means you can put some shallow-rooted groundcover around the roots, or simply some mulch--just something to keep the hot sun off the root run, and promote moisture retention in that spot. But be sure your vine grows into plenty of sunlight, which promotes heavy flowering.
Soil is important. Clematis do best in neutral or slightly alkaline soils, but they are somewhat adaptable. If you have very acid soil, try to add some calcium when you plant. Also, be sure to dig the hole deep. Remember you're planning to have this plant in place for decades.
Where to plant is important. These incredible vines are some of the most beautiful flowering plants, and we've all seen them blooming lavishly on fences, porches and trellises. They're not really hard to grow, and they get larger and stronger every year. Sometimes they take their time getting going, so be patient. It usually takes about two years for a newly-planted vine to come into its own. The large-flowered types are hardy into the very cold north, so almost everyone can use them. Be sure to place yours so it has something to climb---fence, trellis, or post.
Winter and spring care are important. In very cold places (like Minnesota), the winter kills the whole vine right down to the dirt. They actually "disappear." Then in the spring, they are somewhat slow to emerge, so you must protect the spot, and watch for the shoots. Once they pop up, they grow fast, but beware--they are brittle! If you happen to break off the young spring shoots, it sets the vine back terribly, so it's important to watch and care for the new shoots until they really get going up your post or trellis.
Ernest Markham should be pruned back hard (to nearly soil level) in early spring.
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