It’s hard to mow around them so I want to add moss about a foot around each so I don’t have to mow close to them. I’ve been trying to research the best mosses for this but have been having a hard time finding info. I live in SW Virginia and my yard has a lot of rocks and clay. If it isn’t cost prohibitive, I’d like to moss in the whole garden area so that I don’t have to mow near the plants and risk flinging grass and weeds on them.
If your raised beds are in full sun, then no moss will ever grow around them. I can offer you two alternatives:
- Bricks, or brick-sized pavers, set up against the edges of the beds along all four sides. You don't need to spend a lot of time setting these, as you won't be walking on them - just dig a 1.5" deep, brick-width, flat-bottomed trench and drop them in. They will act as a little roadway for the mower's tire as you mow around the bed. You may have to spot-treat the inevitable small gaps between the pavers when grass infiltrates.
- Irish Moss, also called Pearlwort, is an extremely low-growing perennial that likes full sun and will take some shade. Like moss, it spreads over time to form a pretty impenetrable groundcover. It also blooms, with tiny white flowers in June. Pearlwort (close-up): and growing on a landscape fabric path (the olive-green stuff is a weird alga):
One note about moss - it is NOT a very walkable surface and is easily killed by too much foot traffic, so if your beds are in shade and you can introduce moss, you can walk on it, at most, maybe once a week without damaging it.
You may find moss won't grow there if the area is sunny - moss likes damp shady areas. Have you considered growing a chamomile strip of 'lawn' instead if the area is sunny? Information on chamomile lawns here https://www.rhs.org.uk/advice/profile?pid=281 though this is a UK link, so you will need to check whether the recommended chamomile variety will grow in your USDA zone.
A few years ago I had a contract maintaining the gardens of a block of flats in London. There was a large area of bare soil that I kept clear of weeds by spot treating with Roundup (active ingredient - glysphosate) every couple of weeks or so. Roundup kills all green leaved weeds but doesn't kill moss. After a year or so the bare soil had turned into a lovely mossy carpet. Roundup will happily kill your grass, so you need to be very careful applying the stuff. Chose a calm day and follow the instructions. The advantage of this method is that natural selection ensures you get - for free - the moss species best suited to your location.