I am assuming that you know that Clematis don't need shaded roots, but need even moisture instead. Mulch will help with this.

"They all get afternoon shade." Does this mean that just the Clematis get morning sun or will the perennials in front get some sun in the morning as well? Is the shade where the perennials will be growing relatively bright or dappled shade or is it fairly dense shade? Light levels will make a difference to what you can grow. I am assuming from your comment that there is too much sun for hosta(?)

"What is a good size plant to put in front of them?" I am a bit unclear - are you asking about the best size or do you want a medium to large plant?

I would plan to grow either something with shallow roots that won't interfere with the Clematis or tap roots that won't spread. I'll wait to make specific suggestions until I have a better idea what you have for light and what you are looking for.

nhbabs, sorry for my late reply. I am posting a picture so you can see what I have planted. Many of them will be moved soon. I know the clematis don't need shaded, however, I would like to hide the root stems as they do not look great by the time it gets really hot here. But I still want the clems to get plenty of Sun. Looking at my shade map I did last June, the whole bed gets sun from about 10:00 am until 2:00 or 3:00 pm, then light shade the rest of the day. I would like some medium size perennials that will not multiply the way the daylilies do, as you said, with shallow roots, or small shrubs. I have Heuchera that I planted last year at the border of the bed that did ok last year. We have many days over 100 degrees, and the clems do appreciate a little shade. This is the one bed that gets watered more than the others.
As far as the hosta go, It may be too hot and dry, or I am just not good with hosta. We have amended clay soil, slightly alkaline, that may be the problem.
The huge crape Mytrle has grown and has been pruned up to tree style, so it won't shade the clems behind it.
I hope this helps, I was just wondering what other people plant with their clematis.

Debra,

Try fragrant Hosta like So Sweet. These are plants that come originally from a warmer climate in southern China, they will do better in Texas. And do mail order, you won't find a decent variety of Hosta in nurseries in your area. Here's a pic of So Sweet.

Steve

Thanks for the photo - it makes things much clearer. Four or five hours of sun and bright shade after that is pretty good light. I think there are some of the Salvias such as S. greggii cultivars or S. guaranitica (I love 'Black and Blue')or some of the other less hardy Salvias might work for you there. Check for height and problematic self-seeding or spreading potential in your area since it is quite different from my growing conditions. Here many of them stay around 2 1/2 feet and S. greggii is airy enough that it wouldn't block the Clematis even if it were taller.

Some of the shorter Baptisias should work well also. The species and some of the older hybrids like 'Purple Smoke' can get taller than 3', but several of the newer hybrids are more like 2'. Out of bloom I find the foliage decorative.

Look at Amsonias to see if any are appropriate for your area. I like A. hubrichtii for its spring flowers, feathery summer foliage, and stunning fall color. It seeds some here, but not a lot.

You might find some Penstemons that will work for you in this setting to add flowers, but in general when not in bloom they aren't tall enough to block bare lower stems.

Lavender or some of the colored forms of culinary sage (Salvia officinalis) might work here, and you can check out the shrubs forum to see if there are other short shrubs or subshrubs that work in your area. The TX and OK forums are pretty active and my have some suggestions for you as well. (I am assuming due the lower zone that you are farther north in TX.)

I'd love to hear what you end up planting.

nhbabs,
Thank you for taking the time with your suggestions. I do have 2 salvia's, Red Sage and Glitter, that I planted last year, just love them. They are airy, and they would be good there. I will have to look for a "black and blue". I have never tried the Baptisia, but I would like to. I will research the rest of your suggestions and see what I can come up with. I do have Penstemons ordered for my other garden.
I am in the Texas Panhandle, north of Amarillo, the High Plains, but we are also considered desert, so you never know what might do well, if I want to water enough. I have planted mostly drought tolerant butterfly friendly plants in all of my other beds. Lots of Lavender and herbs.
I will let you know what I can find, and post a picture when all of my clems start blooming. They all have new growth already, so I say spring is officially here in the Panhandle. Thank you again for all of your time and expertise.

This is what I have done with the Clematis bed this spring. Let me just say that my clematis have never looked this bad plant wise. We had a late freeze, and than we have had a record breaking 99 degrees and 30-60 mph winds for weeks. They are loaded with blooms, but the plants look beaten and the leaves are all curled up. Nellie Moser, Elsa Spath and D of Edinburg are very light green, I think they need some Alfalfa Tea. Since they are loaded with blooms do I need to wait until they are finished to give them some? I fed them all with Grow Power 3-12-12 in early March.
I removed the roses and hydrangeas, thinned the daylilies, and moved them further away from the clems. I added 2 salvia, and a yarrow, a red Columbine, more Huechera, that are also burned up, but recovering. Can't wait until the salvias bloom this summer.

What a beautiful bed!!
My favorite plant is walkers low catmint. It grows well , attracts bees , blooms all summer , you can cut it back if it gets too big . Makes a great border plant. I used to have a row of it with Asiatic lilies and the combo was just great !! I think it would hide the bottoms very nicely !

I don't know for sure, but I believe I've heard to fertilize after they bloom , that it could possibly ruin the current blooms. Hopefully someone who knows will tell for sure. But I think alfalfa tea will be good for them ! I did that once to my roses and it was crazy how much they grew. But I'm not sure I can stomach the smell again. I mean , It was awful and I was apologizing to my neighbors all day about the smell ! :)

If you fertilize after they set buds, they say the flowers just won't last as long.

Thanks flowergirl and lilyfinch,
Since the clems that are looking needy are all type 2, I will wait until they have bloomed before feeding again.
I do love Nepeta, I have it in several other places, I may put some in next year if the Heuchera don't improve.
Debra