Even though late winter/early spring pruning is best pruning in fall after flowers turn brown is acceptable too.

What zone are you in ?

If you Have a picture that helps.

Limelight is quite vigorous so it should be growing at a good clip. So, where are you located? USDA Zone and map wise? Some of the early blooming paniculatas may have flowers or some broccoli by June 7 down here but further north, it would be only foliage. Is yours well mulched? Have you had a late, long winter? Have deer been visiting and eating the foliage?

I’m in zone 6b. I usually cut back my limelight in early spring. Have never done it in fall. I’ve circled the couple of green leaves that have appeared.

Lots of bunnies this year. The ground has been VERY VERY WET. Flooded for the most part. Have only been able to cut the grass 2 weeks ago. I was told not to mulch until things dried up. The ground around the plant appears dry but the top is only crusted and it is still quite soggy underneath.

Its hard for me to pinpoint what went wrong, but unfortunately something went badly awry.

it should have plenty of new growth by now. You can see what happens over summer but i don't see how it can bounce back.

Its certainly possible the late season prune, combined with weather conditions ended up being too much.

I think come August, you’ll have blooms

I can see three potential issues, only one of which relates to the timing of pruning. I don’t have any way of knowing which of the three may be causing the poor leafout.

Since there are lots of bunnies, I would sink a couple of posts and create a large ring of chicken wire or mesh fencing to protect it. It may be that as buds swell they are being eaten off. If this continues for long enough, this can weaken or eventually kill the plant.

The fall pruning may have meant that the plant hadn’t completely gone to sleep for the winter and so during a warm spell during what was a long fall the buds that had developed for this spring started swelling to replace the missing branches and were subsequently killed by cold. So the buds that are developing now would be newly forming. Panicled hydrangeas are one type of plant that will form new buds in spring if old ones were removed, but it may delay leafout a bit in some circumstances.

Overly wet soil is generally not appreciated by panicled hydrangeas and much of the Midwest and northeast has been overly wet this spring. They prefer well drained soil and once they are established like yours, I never water mine. If this one does kick the bucket, a replacement should be in a spot that won’t accumulate water or it should be planted on a slightly raised mound that won’t be saturated.

Let us know how this turns out. Generally, these are plants that are easy and healthy with a long season of appeal, so really valuable garden plants.

Thanks so much Everyone!

Normally this is not a wet area but we’ve had such flooding where we are since early spring. I’m one of the lucky ones where I don’t have a faux lake still occurring on our property.

I will keep my fingers crossed that although it may not be pretty this year that next year it might have a better year.

I have pruned my limelight in the fall and it came through just fine. I didn't prune it back as hard as you did, though. My limelight is currently full of leaves. But having any green leaves at all is a good sign!

If the OP prunes harder, won't that induce dormant buds come out from the rings/collars

Not sure what the proper word is for the rings/collars I speak of ;-/