Your twiggy branches may be big branches in a couple so consider why you want to prune them. I do not prune my hydrangeas unless they get too close to areas where the growth is a problem. Branches that cross may make me prune and dead stems/branches get pruned in May but other than that, I just do not prune at all. Unless there is growth that really gets under my skin for some reason. Like roses. You know those well known stems that zoom to the sky unexpectedly in what seems to be just a few days? Ha. Roses? Well, sigh, yes, I do prune those so I do not want more work if the hydrangea plant fits in the area where it is planted.

Luis, okay this is good news. I don't have to prune them. I can spend more time with my roses. lol - Thanks again Luis.

THANKS, I was just looking around at the ones within a small courtyard house-surrounded with them; they were so gorgeous this past year. I was wondering as well about pruning, and so here is my answer!!

I see a window in your picture, and if you don't want it obliterated :-), I'd be pruning those. At a minimum, I'd prune all of the very long branches back to promote a fuller shrub. A mature Limelight can easily grow 5' stems in one season.

If you search for "how to prune a Limelight hydrangea," I think you'll find a lot of good information.