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.

I was in this same situation about a week ago; ended up going with the tall fescue and it's sprouting really well. A lady at the store says she planted 3 acres of this and it has been doing fine down here in FL so I mean if it will take the summer then go for it. Zoysia can really be invasive and at least down here can get nemotodes and it needs more nutrients. I'm really pleased how fast the fescue has sprouted, it's like an instant lawn. Good luck!

A properly sharpened and set up reel mower will always give a better cut than a rotary. Reel mowers cut like a pair of scissors, the grass is cut by a moving blade against a stationary bedknife. It also gives more even results as the bedknife holds the blades up while they are cut as opposed to being hit by a spinning blade with some lift provided by a suction effect from the blade. After I cut my lawn with a rotary I usually have some missed blades. Reel mowers are the only ones that can cut very short, so if you want to have a fairway for a yard, then you need a reel mower. A bumpy yard however, will give an uneven cut at low heights (the yard will look even, but the grass on mounds will be shorter and in the dips will be longer), and scalping can occur, but this is also true of rotaries too. Rotaries, if their blades aren't very sharp will tear grass blades, so you get ragged edges, which isn't great for grass, although a poorly sharpened reel can have its issues too.

It is really up to you and what you like. Both are acceptable choices for NC. For your current fescue, I would suggest you cut back on the spring and summer fertilization. After that first burst of spring growth, you should not have to mow 2x per week. You should only need to fertilize 3-4 times per year, not 5. As for dethatching, if you don't over water and don't over fertilize, you may never have to dethatch. Zoysia is more prone to thatch than most grasses though, so if it does start to build up, a once a year treatment should be more than enough to keep it in check. Preferably though, you would care for it so that it doesn't become such a reoccuring problem.