Question: What kind of a groundcover can I use between patio stones in my walk? It needs to be low and non-invasive.

Answer: Best choice for shady sites in most of Texas would be dwarf mondograss planted slightly below the grade, so its top leaves would extend up to the surface of the stones. Some of the sedums would work well in the sun, as could the low-growing Peruvian verbena. In certain circumstances one of the really dwarf bermudas or zoysias might be attractive.