This was posted in the Natural Chicken Keeping thread just days ago really good for quick reference. Great thread idea

keep em coming. Couldn't get red font to work on IPad
Basil - antibacterial, mucus membrane health
Catnip - sedative, insecticide
Cilantro - antioxidant, fungicide, builds strong bones, high in Vitamin A for vision and Vitamin K for blood clotting
Dill - antioxidant, relaxant, respiratory health
Fennel -laying stimulant
Garlic - laying stimulant
Lavender - stress reliever, increases blood circulation, highly aromatic, insecticide
Lemon Balm - stress reliever, antibacterial, highly aromatic, rodent repellent
Marigold - laying stimulant
Marjoram - lay stimulant
Mint (all kinds) - insecticide and rodent repellent
Nasturtium - laying stimulant, antiseptic, antibiotic, insecticide, wormer
Oregano - combats coccidia, salmonella, infectious bronchitis, avian flu, blackhead and e-coli
Parsley - high in vitamins, aids in blood vessel development, laying stimulant
Peppermint - anti-parasitic, insecticide
Pineapple Sage - aids nervous system, highly aromatic
Rose Petals - highly aromatic, high in Vitamin C
Rosemary - pain relief, respiratory health, insecticide
Sage - antioxidant, anti-parasitic
Spearmint - antiseptic, insecticide, stimulates nerve, brain and blood functions
Tarragon - antioxidant
Thyme - respiratory health, antibacterial, antioxidant, anti-parasitic
Fresh or dried herbs in your nesting boxes not only work as insecticides, but also have anti-bacterial properties, and can act as natural wormers, anti-parasitics, insecticides, rodent control, stress relievers and laying stimulants. They will help a laying hen feel safe and relaxed while she is sitting, and calm a broody hen, as well as repel rodents, flies and other parasites. Plus they look so pretty !