Gardening and Horticulture - help my clematis

I have three clematis that are very spindley and only bloom once. They look very sad. I have never cut mine back but wonder if I should. Would this help them fill out? I live in western Oklahoma and it gets very hot and dry here. I also wonder could it be because it may not have been a healthy plant to start with or should I say not a good hybrid.

Any help would be appreciated. :)

Hi jo_ey

Try this knowledge base.
http://clematis.org/home.html

We just cut the down in early winter when you are burning all the garden trash. Get some rotted from someone with Cows or Horses pile a good pile on & by Spring you should have many shoots.

Not trimming back a Clematis you just get a big ugly mess. Clematis does best on new vines each season. Fish emultion with liquid is a good plant food for biweekly feedings. Our Pink, purple & White Clematis cover themselves with lot's flowers for a big show then just go down hill slowly until Fall.

Some clematis will only flower on old wood, others only flower on new wood.
At this point you have nothing to lose by cutting them back.

:p One VERY important thing to remember with Clematis...they like the bottoms to be cool! Keep the roots and the bottoms of the plants shaded and cool. Apply mulch or better yet, plant some kind of non-invasive ground cover at the base of the plants. I use hostas and lily of the valley. I also have one plant with daylilies as the ground cover and it just LOVES that. Also, make sure the tops (where they are to flower) are in full sun.
Cutting them back depends on the variety as Bob said. Watch your plant...if it has grown leaves on some of the plant but there are no leaves on other parts and the wood is brittle, your best bet is to trim those that do NOT leaf out, to the ground.
Quite possibly your vines may need to mature a bit more for you to get a really good show of flowers. :)