Clematis—Follow the Rules & Your Vines Will Flourish

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Q. Mike: My husband and I had our front yard and flowerbeds landscaped last May. One of the plants put in was a purple clematis, to climb up a light pole in the yard. It looked fine for a few months, but then some leaves started to get black spots. We sprayed with antifungal spray and clipped off the diseased portions, but eventually it all dried and we cut it down to the roots. We would like to have something growing in that spot this year but are not sure whether to wait for the clematis to try to grow back, replace it with another clematis, or give up on clematis and try something else. Thank you!

---Emilie in Springfield, Delaware County, PA

A. There are two basic rules with clematis, explains my old friend Raymond Evison, breeder of some of the finest modern varieties of this flowering vine. One is that it is never found alone in nature—it's always growing up and into another plant. The second rule is related to the first: "Head in the sun and roots in the shade." To bloom well, Clematis must be able to stretch up into full sun, but to survive summer, its roots have to be in the cool protection of shade. In the wild, growing up a big plant like a rhododendron provides both the sun up top and the shade down below.

Now, clematis is occasionally plagued by a plant-specific wilt that destroys the plant from the base up, and last year was very wet in Emilie's part of the country AND she says that her vine was professionally planted and a landscaper SHOULD know to shade the roots. Of course, landscapers should also know not to feed Northern lawns in the summer, not to prune anything in the fall and not to mound mulch up against the bark of a tree. Hmmmm; Emilie—did your clematis have support and a cool shady base?

Emilie replies: It had support to climb and its top was in full sun, but the roots were also in full sun. We learned halfway thru the summer that it liked "cool feet" and added some plants around it, but it may have been too late.

A. OK—that's strike four. You may want to slap that landscaper around a little bit. At the least, they owe you a new plant. And considering the location, I'm thinking it should be a different kind of climber.

Q. I have a white clematis vine that has not produced any flowers the last two years. It faces north but receives good morning sun. The vine is about five years old and flowered well the first three years. Two years ago I cut it back and it didn't flower. Last year I did not cut it back and it still did not flower. Can you give me some suggestions on this pesky plant?

---Diane Buck in Milwaukee, WI

A. Well, you don't say when the flowers used to appear or what time of year you cut it back. But if you followed the unfortunate advice of many American garden writers and cut it back in the fall to {quote} "clean up the garden", you're lucky it's still alive.

The aforementioned Raymond Evison—who I believe is part clematis himself—has some good pruning advice at his website. What I like most about Raymond's advice is that he refers to the bloom time as well as the type of clematis in timing any pruning.

As with virtually all plants that bloom in Spring, the best time—make that the only time—to prune clematis vines that bloom early in the season is right after the flowers fade. Same as with azalea, rhododendron, forsythia, lilacs and all the other shrubs of Spring. Remember, if a plant blooms early in the Spring, it means the buds were already there; prune it in the fall or winter and you cut those buds off. Raymond adds that pruning of most spring bloomers is not necessary to get a good show; the only reason to prune a basic type of spring blooming clematis is if it's getting too big. You wish.

But Raymond adds that certain Spring bloomers—one with especially large or double flowers—are an exception; these types bloom better if they get a little haircut at the end of winter to remove any dead or damaged parts. Just a little trim, mind you, and stagger the cuts for the best show.

Finally, Raymond's site says to cut summer flowering clematis back to—what's this? "Thirty centimeters above the soil line in late winter/early Spring"?! Raymond—centimeters? This an American gardening show, pal! Grumble, grumble.... Where's that double-sided ruler of mine? Here it is. OK, that's about a foot. Geez Ray—next time, just say so!

Anyway, if it wasn't the pruning what held back your flowers, it's probably lack of light. "Morning sun" sounds suspiciously like a synonym for shade to me, and if the top of your vine isn't getting at least six hours of sun a day, it probably isn't getting enough. But if it is—or if its getting somewhere close to six hours—try mixing a cup of bone meal into its soil this Spring, then cover the bone meal with an inch of compost. And maybe prune back a few nearby plants to let a bit more sunshine in at the top while still shading the base..

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