Becky,
I have been trying to find answers to this question as well. I get lots of other information, but not any real good answers so far. Have you come up with anything yet?
It is clear, that almost every coop build talks about putting the hardware cloth around the outside and burying it to keep predators from digging under, but that would not work on a chicken tractor. So, I'm trying to come up with something on my own.
Here is what I am going to try. I will attach a 16 in wide strip of hardware cloth to the bottom rails on all 4 sides, over lapping at the corners. I think, I can easily bend it up off the ground in order to move it. Then, as cumbersome as it might be, I will lay 2x4s along the edges of the wire and have several holes drilled in them about 2 to 3 feet apart and pound a into the hole that will hold it down. We have clay soil, so I think the stakes will hold. I think this will be a lot of work, but it will do the job. Because I won't want to have to move this every day, I am building the tractor as large as I can without it being to hard to move. I am also going to use portable electric fencing and create a large 40 x 50 foot area for them to forage. The weakest part of that idea is that we have hawks, however I will use some tarps to create an area for them to duck for cover, plus they will be able to run into the coop which has wire over the top. I'm going to try keeping a rooster, as they are good at warning the flock about hawks. At night they will be secure inside the roosting area.
I think the method with be about as secure as one could hope for. Moving the coop with will be a bit more time consuming and labor intensive that otherwise, but even if the area is tapped out of grass and bugs after a few days, I don't plan on moving it more than once per week. I am going to start with 10 chickens, so I'm hoping a week will be just about right.
I hope this helps.
Natalie
