I have plants in my run. Several Alberta Spruce, one Euonymus Fortunei, a Weeping Cherry tree, and one very big Blue Spruce tree. So far they have left the Euonymus alone, I just put that in the run, I had to move it from a different area of the yard. My run is about 40' by 20' so they have alot of room as I have only 3 standard hens and 4 bantams. They jump up and eat the cherry blossoms but its an established tree so no harm. And the Blue Spruce has been in the yard prior to us or the chickens. I worry about them causing the blue spruce problems, thats where they like to root and dig so I need to keep dumping the extra dirt and such from the other areas of the yard to make sure that the roots stay at the same depth. But I will keep adding plant and bushes to the run, I think they need that. Also my chicks that are 7 weeks old are in the coop now. They have a section in the coop that has small openings that keep the older hens away and they have a small opening to go out in to the run. The five Alberta Spruce are in a row and gives the chicks a place to hide from the hens. I couldn't have the chicks outside with out that protection.