Most Clematis need full sun, but a few need some shade. They south side would be a good place to start. All clematis do need their roots to be shaded, i learned that planting some short-bushy annual at the base of it helps to shade out the roots. Good luck with it, i love buying mystery plants!!!
Sarah

In your zone 9, I would give the clematis, especially since you don't know the variety of one, morning sun and afternoon shade. Type II clematis in my zone 7a garden can get quite burned up in afternoon sun in the middle of the summer so the sun in your zone 9 is going to be even hotter and more intense. Planting them in an area where they get protection from the afternoon sun would also help in moisture conservation.

Clematis do not need their roots shaded. They need an adequate supply of moisture. Providing mulch at the base of the plant will provide the moisture conservation measures you need to help your clematis out. Planting a bush at the base of a clematis is going to be counterproductive since it will be in competition with the clematis for the moisture and the nutrients in the soil. In addition, the use of an organic mulch will add organic matter to the soil as it decomposes and thereby add more moisture holding capacity to the soil.

If the plants are small and in bad shape, I would recommend not planting them in the ground now but rather potting them up into one gallon sized pots and growing them out for a while. When you pot them up, plant them several inches deeper in the pots than they were in their original pots. If you decide to go ahead and plant them in the ground now, then plant them as described for pot culture.

Giving the plants a good haircut now would be fine in your zone since you live in a zone where things grow essentially year round and the cooler days of fall would allow them to get a good start in producing foliage.

Miguel is right..Sarah..in your zone the sun isn't as hot and intense as we Southerns have and growing clematis here is different..they can't take as much sun as they can further north..I would do as Miquel said and plant in an area that you know will stay moist as the roots need that..Morning sun and afternoon shade is purrrrrrrrfect...Jeanne

I'm sorry, i didnt even look at the zone! oops!!!
Sarah

no problem hon..we've all done that before...I'm guilty too..thanks to others here who read and respond..we can all keep each other on track..LOL...Jeanne

Yep, it is easy to respond without looking to see the zone the original poster is in. Done it myself. Now I always try to go back and see where the poster lives before offering advice.