Hi!
I need to plant something in the cracks between the flagstones in my backyard. I have sand in there, but it doesn't stay in and makes a big mess, so I'd like to put a little dirt in and plant something, but have no idea what to plant. I heard somewhere maybe Scottish moss, but don't know where to get that, or how much it spreads? It's in a pretty shady area, and in SoCal, so no water to speak of, except where the sprinkler heads overshoot the yard.
Any suggestions?

Pennyroyal may be worth considering. Smells good when you walk on it, (s'posed to keep flies and fleas away.) Likes a moist shady environment and the soil underneath the flagstones would probably retain plenty of moisture for it.

Hi Longy. Thanks! I'll look into that one. Any other suggestions from anyone else?

Scotch Moss spreads pretty slowly and requires quite a bit of water to get it established. What about Wooly Thyme or Silver Thyme?