These are tough plants. If it has living roots and you prune it severely, it will come back. But with anything, it takes a little while for it to get the energy to do so. Mine are flowering already, so yours should be leafing out now if they are going to.

I have an Itea in my foundation planting. Like the Clethra Hummingbird, it suckers. My Clethra is planted where the suckering is welcome, but I am planning to move the Itea because of the suckering. The height is just right, about 5-6ft and stays under my front window without pruning. It does flower and there is a nice fragrance though mild most days and it does have fall color, although not the bright red that one of the cultivars gets. It really does seem to manage without much attention and is fairly drought tolerant, mine has no pest problems that I've noticed. but I have mine facing East and it gets about 3-4 hrs of morning sun and it blooms fine.

Me again...We have sweetspire (itea) cultivar 'Little Henry', some from Musser, some from Lowes. The oldest are 4-5 years, about 3' x 3'. They do sucker, and also will self-layer, but I don't think their behavior is invasive. I WANT mine to increase, because I need to cover another area. They are also pretty easy to start from cuttings.

i simply told you how i would do it on a valued plant ... in other words .. i wouldnt spend 20 bucks on product on a plant i can replace for 10 ... eh??? when i buy a $100 conifer.. and scale shows up ... i am going to save it.. period ... its worth the further cost .... as to whether you want to use it.. feel free to google up alternatives ... though i am positive you will find millions of tree and bug huggers telling you its not a good option ... and i say pshaw to them .... if i lose 3 worms or bugs ... to save that valuable plant.. so be it ... there are bazillions of them around ... hort oil is an organic alternative ... but the application regime.. was beyond my patience .... you have to spray when the invisible crawlers come out from under the dead momma ... good luck with that ... lol ... i was never there.. the day that spray was required ... ken