Because pests and predators will often try to tunnel under a barrier to get to the chicken goodness on the other side, some coop designs, including The Garden Coop, call for burying the hardware cloth down about a foot or more on all sides. You might think the wire would rust faster down there because of the moisture, yet because it’s exposed to less oxygen in the ground, it actually tends to last even longer. I’ve read of hardware cloth being unearthed intact after 30 years in the ground. So this shouldn’t be a concern.
Hardware cloth will not rust.
Thanks so much for the answers! I have hazelnut bushes that I’m keeping in a shrub size. They produce wonderfully but as soon as they’re ALMOST ripe enough to harvest, the squirrels have gotten them. I’m making a hardware cloth “cage” for the bushes by putting a trench around them, and setting the bottom of the hardware cloth into concrete there, with more soil above. With all that work, I’d have been very bummed if the hardware cloth rusted off! (Yes, I am putting h.cl. over the top.)