Hi, My friend just built a fieldstone patio that is now home to a hot tub, I will be landscaping this patio for her and I was thinking of growing moss in between the fieldstone to "soften" it, what would be the best moss for that purpose? The patio is in shade with only about 2 hours of direct morning sun, also they have put crushed limestone in between the rocks. Will that interfere with the moss?? Thank you!