We have had great success in the garden with Symphotrichum ericoides 'Snow Flurry' and are now looking for similar plants in other colours to add to the mix. I know that it comes in other colours, but I haven't been able to find other prostrate forms of S. ericoides in my hunt online. I am looking for recommendations for ground hugging late season asters or other plants that can handle US zone 5/6 temperatures. Many thanks in advance.