Thank you. A lot of areas of the US certainly get hot in summer but I thought clems could grow in most states here if mulched well. I thought I'd read that they can grow in Australia , which I'm thinking is hot and dry. I know there are one or two guys in my state, NC, who grow clems and must have good success with them. I was thinking that if I try more of the viticella type that I might have better luck with them. I guess I'll just get a few more this year and see how they do.

Summer heat is not usually a concern provided you keep the root run properly moist. And mulching will help. Desert conditions are different as are areas with high summer humidity (deep south) or a frost free climate that doesn't allow for a full dormancy. And yes, some species are native to Australia and New Zealand but they can have some pretty variable climates as well - it is not all hot and dry :-)) And the species native to those areas tend not to be completely winter hardy in most of the US either.

One of the most frequent and valuable contributors to this forum (he passed away a number of years ago) lived in NC and grew scores of clems. Even grew some from seed and hybridized a bit. Brushwood sells a clematis named for him - C. 'Miguel Viso'. So yes, you can grow clems in NC!! And not just the viticella types :-)

Here is a search for Miguel's posts by his user name Nckvilledudes's posts. I seem to remember that he had the best success with Viticella and other hard prune hybrids, though he tried others.

Yes, that's the guy I was thinking of. I read some of his posts many years ago and more recently as I've become more interested in clems. He seemed to know a lot about them. I'm sorry to hear he's no longer with us. His old posts are a lasting gift.

The reason I wanted a book by a warm climate person is that they'd be more likely to have tips for my climate. NC summers can get hot but we lived in TX for 12 years and it's nothing like TX. Keeping plants moist would be a challenge at times .

I am wondering about mulch. I use bark mulch, but I've noticed that if there's something solid on the ground like a rock the ground often will be more moist under that than under mulch.

Maybe put a slab of rock over the root zone?

I've been reading about rocks around plants a little. I think if I used any that smaller rocks might be better than one big rock because rain can get in between the smaller ones. White rocks might be better than dark ones as far as heating up goes. Bark on top of rocks could be effective mulch also. Might try it. I think too thick a layer of bark mulch prevents some of the rain from reaching the soil.

There are a few issues with using rocks as mulch. They can heat up and take a while to cool down at night which some plants find stressful in warmer areas. Gravel is more difficult to weed around as it is harder to pull out roots and they eventually mix with the underlying soil unless you use landscape fabric which has problems with interfering with movement of air, water and nutrients in the soil. Rocks don't add nutrients or improve soil tilth. With an organic mulch such as compost, shredded leaves, pine straw, or shredded bark, as it breaks down, it improves the soil and is easier to remove weeds as well.

Both types of mulch will help conserve soil moisture, moderate soil temperature, and reduce weed germination. Just don't put it on super thick, and water plants as needed.

Highly recommend a very pretty book packed with color photos, practical advice, planting diagrams & charts for combining roses & clems - The Rose and the Clematis as good companions by John Howells. My copy's from 1996, sports 30+ sticky notes & continues to provide a clear method of evaluating both roses & clematis by their characteristics, so proves equally useful for cultivars not mentioned in this volume as new introductions appear on the market.

The very clarifying viewpoint this British author conveys works well for me in this Virginia garden. Reprinted in 2007, the book includes "140 colour plates & 75 colour & black and white drawings" for visual appeal within 205 pages divided into 12 chapters. To give an idea of the depth explored, there are separate chapters for clematis on climbing roses before the roses flower, when the roses flower, after the roses flower, under climbing roses & near climbing roses. Ditto for shrub roses, bedding roses & container combos. Widely available online & very reasonable second hand. One example. https://tinyurl.com/yc5q4n81  Another of his excellent books is Trouble Free Clematis: The Viticellas. Sue