Rupturewort

I'm looking for a ground cover that will get thick enough to block most weeds. I planted Lemon Frost thyme about 3 years ago and like th...Read Moree look but it's a constant struggle against weeds. Sedum from my rock garden started growing on the edge but fairly quickly is overwhelming the thyme - not to speak of the many other plants (weeds) that I have to remove. I'm considering transitioning to sedum or Rapturewort. The area is about 8' X 12' and gets a lot of sun. I live in Maryland - zone 6b. Any suggestions?

Can't say enough positive things about it. Just outside of San Antonio, this survived a winter that saw snow, a freeze that lasted a wee...Read Morek (twice), and a summer that went over 110. It stayed green and vibrant throughout all of it; needs very little watering once established. I planted some in amended soil, some right in loosened clay; no difference in growth or water needs in my experience. It's just a great, behaved lawn replacement once you weather the 3-4 months it takes to start looking less patchy.

After a while you'll find a scant handful of stems slowly rooting themselves here and there when you lift some of the plant's sides up (contrary to what you'll read). I was able to break those off, plop them ~1/2" into the soil, water them every few days, and end up with entirely new growth that very slowly worked to fix a few bald spots here and there.

During windy days it can look like you have a flopped over toupee at the very edges of where it grows, but I don't mind just flipping it back against the ground. Much better than the mowing and weeding grass lawns made me sweat through.

As for day to day, when it's really happy it'll fluff up to ~3" thick, it takes a decent amount of foot traffic, and suppresses weeds far better than grass once established.

Really, really happy with it.

Really interested in trying Herniaria glabra for our roof garden but concerned about its "long taproot" causing damage. Does anyone know ...Read Morehow deep the taproot can reach and if it is considered as an aggressive plant in that respect? We need to know this so we determine if a root barrier is required to stop the roots reaching the insulation layer.

I think the zone 7 rating is a much repeated assumption. There may be certain specific conditions for different zones, (i.e. drainage, am...Read Moreount of summer heat, etc.), but I'm not sure. I do know that it is naturalized in Quebec and Ontario, so it's going to be at least zone 5 hardy. Some claim it is a zone 4.