Most perennials will take a little while to really get going--there's a saying that in the first year they sleep, in the second year they creep, and in the third year they leap. So I'd give them a little more time. Chances are they'll grow more and probably bloom a bit next year, but then the year after you should really notice them start to take off. So make sure you're giving it the right amount of water, fertilizer, etc but then all you can really do is sit back and wait. I wouldn't expect it to do too much this year though
That's especially true of Sweet Woodruff - it takes time to fill in -- several years. Once it does, some people complain that it can be invasive, but I don't find it to be. I've had it for 15 years, and it still doesn't fill as many spots as I want it to.
I planted some last year and it didn't bloom, but this summer it spread like crazy and also bloomed well. I think I'm a little nervous now if next year is the "leap" year! Do I have to worry about the hostas I have near it or will they just push up thru it? Yikes.
I've wondered the same thing. But my hostas (so far, at least) are pushing up through it just fine, except for short hostas which look as if they are struggling a bit. . I may pull it back a little bit from the base of the hostas.