We have several of them in our yard, and every year I hack them down by at least 2 feet on all sides and the bottom, as well as thin out the interior. It's a huge job and takes a full weekend. Here's the thing ... they grow back twice as full after trimming. One year, I hacked them back so much that my husband issued a trimming citation to me. It was all for naught, though, because the beasties grew back twice as full. It's a weird catch 22. If you don't trim them, they'll over take the landscaping. If you do trim them, they grow back with gusto. We even had one plant that we hacked right down to the ground. That was about 3 years ago, and now the thing is HUGE. They only bloom in the spring providing tons of stunning color in the yard and pollen for bumble bees. There's usually a ball and frizbee or two hidden in it's depths. Jeepers! I'm just thankful it hasn't swallowed one of the kids yet. It's a jungle in there.
In the photo, you can see that these plants are heavily weighted down with flowers. No scent, just lots of beauty. Once the flowers fall off, we'll "dead head" the botanical beasts, and then its time to wack the behemoth back a couple of feet.
