I haven't decided what to do with my Hummingbird yet. Luckily I didn't p*lant it in an area that is a big display area without realizing it leafed out so late. I really enjoyed mine the last couple of years. Pretty foliage, nice f*ragrance. This year, it seems to have died out in the middle some and it suckers at the same time, so it looks odd at the moment, with growth coming up in the middle of a neighboring geranium and some bare branches in the middle. I am definitely not going to get rid of it, but may have to p*lant it in a different location. One good thing about it leafing out so late, the Winter Moth Caterpillars haven't made a mess of the foliage!

Peat, despite its long history as a soil additive, really isn't great as an addition - it tends to dry out easily, and is then hard to re-wet; it is actually slightly hydrophobic when dry and will repel water, so needs soaking to re-wet itself. However, it's there, so just be aware of this, and try to keep the soil moist. Holly Tone, or another fertilizer for acid-loving plants is better at keeping the soil slightly acidic - and if your soil is VERY alkiline, then you are better off to grow plants that like those conditions, or build a large box and import soil into it for acid-loving plants. I may be making too many assumptions, so my aplogies if so. Do you know if your soil is acid or alkiline? My clethras do fine in my slightly acid soil, but I understand that they are pretty adaptable as to the pH they will grow in, so am not sure that is a problem for you, despite the above comments. Despite having "good rain", it may not be enough to wholly wet the root area, and the Clethras may be lacking water. Can you dig down around the roots and see if the soil is evenly moist down 6-8"? If it is dry down that far, then really soak them, and try to keep a better feel for how wet the soil is. Mulching helps with soil-moisture fluctuations, as you saw this summer, but how well they grow does depend on how big a root structure the shrubs have and how wet it really is down at root level.

lisasml, that happened to me just recently with all the rain to my clethora ruby spice. My mother (with 60 years of gardening behind her) told me that it was b/c it had grown so quickly b/c of all the rain, etc. So...I put chix wire around it to get it to grow straight for the rest of the season. unsightly, yes, but it was NOT going to "spring back" into position. 'hope that helps a bit.

YR, I grow all my clethras in a such shady conditions that clematises will not bloom there, so I never even attempted to try such combo, but I think that clethra with its suckering habit might not be a good host for the clemmi. Another possible contra to this idea is that clethra's lateral branches are not thick enough to support a massive vine. On another side I think this could be a lovely combo, especially considering the fact that clethras leafing out very late and clematis foliage will decorate it early in a season. Hmmm...now when I start thinking about your idea, I think I might try Jacmanii on one of mine C.barbinervis which is approaching 12' mark and have top 6' in a full sun. Thanks for idea.