It has been a very long time since I read that book, but I think he made his flat topped wickets out of either 9 or 10 gauge wire he bought in big rolls from Ken-Bar.

If you are looking for pre-made wire-topped wickets, Johnny's Selected Seeds has them in several widths. I'll link a photo of one from their webpage.

Row Cover Supports for Low Tunnels

Tim built permanent flat-top wickets of PVC pipe for my cattle trough feeder that sits on legs. He meant well, but I wanted rounded hoops and keep waiting for the aging PVC to break so we can replace the ones he built with the ones I had pictured in my mind. The problem with flat-top wickets is that once you put the row cover over them, the cats think you have made them hammocks. And, chickens also like to sit on them and poop onto whatever lies beneath. So, if you can keep the animals out of your garden, flat-top wickets ought to work just fine. I'm thinking about a certain chicken of yours who might be a problem but I won't name her because I don't want to embarrass her.

I've used rounded hoops made from both PVC and EMT and prefer them to wire which doesn't hold up as well to heavy loads of cats, turtles, chickens, wild birds, lizards or snakes. You might not have trouble with those critters, but my garden is filled (too much so) with visiting animals despite having a nice, sturdy fence.

ROFLMAO! I hadn't thought of this draw back. Somehow I knew a flat top would have problems. It just seemed like a way to allow for the same height all across the bed. I often seem to have tall plants near the edges of the bed. DH is trying to figure out how to keep chickens out but allow me easy access. Bird netting was unsuccessful and it appears he has thrown out all my plastic chicken wire that I had been using for fences. Thanks for the link, probably won't worry about it now.

LOL. All I could think of was Speckles (oops, I said her name, don't tell her) up on top of that row cover, possibly lying on it, and probably laying eggs on it. Why not? She'd be up off the ground and comfy, so why not lay eggs there?

We have a chicken who lays her egg each day by the back steps. I can't catch her doing it, but when I walk out the door and find an egg there, I pick it up and bring it inside. I guess she's more of an outside girl than an inside girl, so why not just lay her eggs on the open ground by the back door? She's probably not one of our broody hens----she's more like a neglectful mom-to-be. The fact that the hens still are laying in January is kinda common since we keep having occasional warm days mixed in with the standard big blasts of cold weather, but having a hen just drop an egg on the ground is a bit odd. I guess she's too busy to go back to the coop.