Cleaning up after Clematis Wilt

As promised here is an entry on pruning a clematis that had clematis wilt the season before.  This particular clematis is a jackmanii with beautiful, big, purple blooms that grew like topsy and had to be cut back hard every year and was still a bit of a tangle.  Last season, out of the blue, a huge part of it succumbed to wilt.  Not having encountered this before, I did a fair bit of research before anything else.  The one thing every expert agreed on was the importance of removing and destroying all the damaged material.  So that’s what I did.  Because clematis wilt is blamed on a fungus (differing opinions on which one), I knew it would be very important to remove the dead wood without damaging the healthy wood, as that would create a re-entry point for the fungus.

This is how is looked in late March.  I don’t normally prune that early, but the roses and clematis were both starting to break buds, so it seemed best to just go for it.  As with my previous clematis entry, I just worked my way down in sections from top to bottom, carefully extracting dead sections, and separating them from the healthy stems with as little pulling as possible – and no yanking.  Yanking is very tempting, but counter-productive.

This is the base, and you can see the tangle of stems I’m normally greeted with every spring.  This is a very exuberant plant.  As you will see below, a lot of these stems had to go, but it was really encouraging to see how much new growth was already coming up from the base of the plant.

So this is what I ended up with.  It looks horribly sparse.  But at least the plant is alive and (for the moment) healthy.  One of the experts I consulted felt that the real danger with clematis wilt was that clematis are extremely thirsty plants with stems that are essentially very, very thin straws and they get stressed, and vulnerable to disease if they don’t have adequate access to water.  Part of his reasoning was that he had never seen clematis wilt on plants growing in the wild by streams.  I suspect he has a point, but I also discovered that species clematis (the sort most likely to be discovered growing wild by streams) are not susceptible to clematis wilt – only the fancy big-flowered varieties get it.  So, obviously cutting out the dead material and making sure it got adequately watered was not enough.  So I went out and got some fungicide to spray on the plant.  One expert said sulfur-based and the other said copper-based.  I confess my decision was based on practicalities.  The sulfur-based fungicide has application instructions that were more on a scale that was compatible with the hand-pump I was going to be using, and unlike the copper-based fungicide it did not sport a skull-and-crossbones on the side of the package.  I wore a kerchief over my face all the same, and probably looked like a bank robber who had no clue where the bank was, but what can you do.  (Also, importantly, there are no edibles being grown in this garden, aside from some dill that has only just sprouted.) When I sprayed (early May) I noticed that there was already a stem that looked severely wilted, so I cut that out down to the base and re-sprayed the area, especially the fresh cut.  I’ll be keeping an eye on it to see if these measures are sufficient.