I would flush the roots with fresh water to leach out the fertilizer you put on it. Just be patient and leave it alone. It may not do much this year depending on how much damage was done. If that was the cause to begin with?

Isn't Miracle Grow Bloom Booster something you mix with water and apply?..If so I doubt that was the culprit..maybe you just have a pruning group 2 that wilted again?..If so just cut even with the soil and continue keeping the soil moist...don't forget to water her...Jeanne

I agree with Jeanne. Since it tended to react the same way this year as it did the previous year without the Miracle Grow Bloom Buster, you probably are experiencing wilt that has nothing to do with the type of fertilizer you used.

This particular Clematis is in full sun, whereas my others are in partial sun. Could that be a problem also? I was thinking about digging it up and relocating to an area that gets some shade part of the day?

I wouldn't think full sun in Michigan would be a problem. I have quite a few clematis in full sun in NC. I am going to bet having purchased your clematis at Lowes that you have a type two clematis which are prone to wilt. Relocating the clematis is just going to set it back even more, especially now that summer has arrived. Continue to tend the plant as if it were alive, keep it mulched and watered, and cut off any vines that have browned out.

Thank you all for the info :)