I haven't lived with zoysia but have fought other grasses and many weeds from entering beds. You'll need a barrier that penetrates the ground and extends above the ground. I don't think the common plastic edging would be deep enough. I'd go for 8" depth but someone who's had zoysia might advise better. (You might look at roll aluminum from the roofing dept.) I would definitely ditch the idea of a barrier being in front of the stone based on looks alone. That would not look good. But you could put stone in front of the part of the barrier that sticks up. It would still require some occasional attention (such as spraying with herbicide) to the grass that grew between the barrier and the stone.

I use my compressed air sprayer with glysophate to stop the bermuda grass. It has truly been effective. Just spray a two to three inch width. IF some bermuda grows under, up and into the bed, it's just an occasional strand that can be dug easily.

Think the limestone brick will look great.

HTH, Rosie

The problem with zoysia grass is not only the underground spreading roots but also the dang seeds which blow on the breeze. Building a raised bed against a foundation is not a good idea. A question to answer before I provide a possible answer. Is there an outdoor water faucet positioned in fairly close proximity to this garden bed under discussion?

Thanks for the suggestions! I'll definitely check out the aluminum. We don't especially want to use herbicides, though--we don't use any chemicals in the yard or garden (well, almost never--had to resort to Roundup to get rid of rampant trumpet vine in the garden bed). As for raising the bed, I can give up on that idea. It would probably be too hard to take care of. There's no outdoor water faucet anywhere near the garden bed, which is a problem in summer when it dries out around here ("here" being southern Indiana).

I came across this old thread because we are adjusting the contour of our Zoysia grass lawn And I wanted to check the recommendations for barrier depth. it turns out our old barrier is only 4” deep and it has easily contained the rhizomes from spreading underneath. What we have to watch is those that want to grow over the barrier. That’s just a matter of edging the lawn regularly. Nevertheless, I am installing a 6” deep barrier this time only because we have tree root problems going everywhere, but I think 4” is plenty deep.

I’ve had this zoysia grass lawn for at least 30 years and never regretted choosing it. I chose it because I had German Shepherd Dogs and I wanted a grass that would take ball chasing and peeing. If I didn’t wet the urine spots down when they happened, the grass would tend to die out. But zoysia sends out rhizomes to cover those bare spots rather quickly. It also stands up well to big dogs chasing balls. It is extremely drought tolerant. It is thick and luscious underfoot. and while it does go straw colored dormant in winter, it does not go dormant for long, especially in the warmer winters we’ve been experiencing the last few years. Last winter it didn’t even go fully dormant. To compare, I’ve grown buffalo grass and it has a MUCH longer period of dormancy and is no more drought tolerant and not half as attractive. One more thing, I have a seedless cultivar of Zoysia so there is no seeding about. It’s a great lawn Grass.