I doubt you killed your clematis, but you may have cracked the fragile stems at the base. Keep treating the roots like they are alive and you will probably get new shoots coming up. Best practice is to prune the clematis back hard before you plant leaving only about 6 inches of growth or taller so you have a few sets of leaves.

There isn't a leader vine.

Sweet Autumn grows fast, so keep watching it so you can try to guide the stems.

I add bone meal the way Chalk Hill recommends, but it isn't required.

I don't take out the supports that came in the nursery pot unless they fall off. I try to cause as little disruption to the roots as possible. I do take off the twist ties though and use my own. Tightly tying the vine to your support isn't good. I use velcro straps to hold the vines in place. It doesn't take long for the tendrils to grab on, so as soon as it does, the straps can be removed.

What I try to do when planting a new clematis is plant it at an angle towards the support. That way the vines will already be growing in the right direction. To help it along, I might add a couple of lengths of thin bamboo on either side of the root mass and use these to help guide the vine. It also serves to protect the vine (somewhat) from dog feet. Where practical, I will use the velcro pieces to hold the bamboo to the support, but most of the time it can just rest on the support because the soil holds it in place.

i've used fishing line with great success. you can buy a reel of them at walmart. tie one end to a metal stake in the ground and the other onto the top of the fence, placing as many lines as you want according to the shape you want, fan column or whatever. clematis climb buy curling their leaves around supporting objects so you don't want to use a any support thicker than a pencil..

also, someone else will probably mention this sooner or later: it's good practice to plant your clematis 4" to 6" deeper in the ground than the level of soil in the pot. this will bury some backup nodes along the stem from which new shoots (or "leaders" if you want to call them that) can grow if the above-soil growth gets lopped off. the plant will also root at these nodes creating a stronger plant.

generally, don't judge a clematis according to top growth, look at the bottom of your pot and see if there are roots poking out - if there are it's ready to plant. that is assuming it's in a gallon container or extra deep 12" pot. anything smaller, i usually repot into gallon container and grow until roots fill the pot. the exception is Sweet Autumn, it is such a hardy grower you can prolly pop it into the ground now.

i wish you lots of luck with your clematis, like janet said they are hardy and should come back..

I just planted two Clemantis but at ground level or slightly higher. Was thinking about drainage. Is this OK?
Julyguy

No, you should replant them deeper.

I have a clematis specific kind unknown 3 yrs, the 1st yr it was beautiful, after that it starts off beautiful then just dies down...it's done that 2 yrs now. What's going on.

Deborah, do you know what kind of clematis, and can you add a photo?