I've read that cedar is poison to chickens. Actually, I read it just in time to change where the run will be in my backyard. I had planned to build the run aroumd a DEAD cedar tree. Do you know what it is about the cedars which is harmful? I was told it is the aromatic oil, but it is more likely they would be harmed by eating the needles that drop on the ground. I want to give my hens access to my vegetable garden so I can finally grow squash without bugs and tomatoes without catapillars. Will I be risking my hens by letting them into the garden surrounded cedar limbs? Would it be okay to clean the grounds under the dead cedar and build the run there? Please provide only answers you know to be factual. Thank you.