When we purchased the current house, we looked at a lot of different model homes. In the backyard of one of the models, there was a concrete patio design that we both liked. When we had the landscape plan done, we tried to incorporate the idea. Basically, the design was some square sections with groundcover growing in the gaps between the sections.
The idea never worked. The groundcover would not grow, but the weeds would. At one of the fall dinner parties, Matt asked if we ran out of money and did not finish the project.
The landscape plan originally called for irish moss. I replanted the irish moss at least once. During a different dinner party, the Newlin's suggested isotoma. I replant the area between the 10 three foot square sections at least three times in the last couple of years with isotoma. While the isotoma did better than the irish moss, it would not survive the hottest part of the summer. Additionally, some area did not drain well and were too wet, while other areas were too dry.
We have given up on the idea of coverground. I spent the day digging out the gaps, putting down 30 year landscape fabric and filling in the gaps with polished pebbles.