Expert: C.L. Fornari - 8/15/2008

Question
QUESTION: This is not the place to post this question but the experts in perennials are either maxed out or on vacation, so I am risking posting it here.

We have an old clematis growing up a trellis at the side of our front door. I don't know the variety, it has large deep purple  flowers in late spring. I don't know whether it flowers on old or new wood. It never gives any trouble, it does its thing reliably every year but this year the leaves seem to have died off quicker than usual leaving it looking very messy and almost completely dead. We would like to cut it back. Can we cut it down to the ground?  What would you recommend please?

ANSWER: Patty,
Not to worry - as a "plant nut" I am well versed in perennials, vines etc.

It sounds like you might have one of the most popular types of Clematis called Jackmanii and this blooms on new growth. You can cut it down to about six inches in the early spring before it usually breaks dormancy in your area and it will grow back gangbusters.

If you want to be absolutely sure that this isn't one of the types that blooms on old growth, you can wait until after it flowers next season and then cut it way down.  Just don't wait too long into the summer to do it - cur right after it finishes flowering.

All clematis will produce new growth from the stem just below the cut, so if you want growth way down near the base of the plant make the cut there.

all the best,
C.l.

---------- FOLLOW-UP ----------

QUESTION: What about all the dead leaves? We would like to cut it back now, it looks an absolute mess at the side of the front door.  If we cut it back now what will happen to it.

Thank you for your prompt reply

Answer
Patty,
The problem with cutting it back now is that you'll stimulate new growth - pruning always stimulates growth because the plant wants to replace what it's lost. But at this time of year that new growth won't have time to harden off before winter unless you live someplace where frost doesn't hit until well into December.  Most of the time clematis are so congested that you can't tell where a dead stalk starts and where a live one ends, so if we cut into what we think is dead, we discover that it was actually a living stalk. That said, if you can separate out the dead ones now you can trim them off, or you can pull off the dead leaves as best as you can to neaten the look of the plant at this point. But I'd really advise waiting to do the real pruning job either until next spring or just after it blooms - either of these times would be better than now.

I hope this helps,
C.L.