And you can plant plants, the key thing is to put something around the base so the chickens don't uproot them, @coach723 uses HWC, I use 6" landscape border. I have a couple Texas sage bushes in my run, and 1 crepe myrtle, and in my chicken yard I have 2 crepe myrtles, a fig tree, and an apricot...
You could put a light sprinkling of permethrin dust (Hi yeild livestock powder, seven dust, etc) down on top of your pdz (also I recommend switching to stall fresh, it's the same thing but way cheaper for a lot more product...
Do not waste your money on that, natural dewormers do not work, I'm not even sure those are worms, let me tag some folks @TheDawg @coach723 @Eggcessive