What research exists
The most studied herb in poultry nutrition is oregano. A 2018 review in World's Poultry Science Journal (Alagawany and colleagues) summarizes studies of oregano and its derivatives, chiefly the essential oil, as a feed additive. It identifies thymol and carvacrol as key active compounds and reports antimicrobial, antioxidant and performance effects at measured inclusion rates in formulated diets, for example essential-oil inclusions of up to 600 mg/kg in broiler studies. Those are controlled doses of extracts in commercial feed, mostly in meat birds, and do not show what a handful of fresh leaves does for a backyard hen.
For most other garden herbs, the sources consulted for this page contain no poultry-specific findings at all. They are grown around flocks for the garden reasons listed below.
One important disagreement: parsley
Parsley is often named in lists of "herbs for chickens". Yet NC State Extension's Richmond County office lists "parsley plant" among plants toxic to chickens, alongside oleander, yew and nightshade fruit, while noting its list is incomplete and regional. Given that conflict, parsley is not a herb to offer freely without veterinary advice.
The fifteen herbs
| Herb | Container class (UMD) | Garden role in the sources | Poultry-specific note |
|---|---|---|---|
| Oregano | — | Attracts bees and butterflies (UVM) | Most-studied herb in poultry feed research, as essential oil and extracts (2018 review) |
| Thyme | Small, 1–3 gal | Attracts bees and butterflies (UVM) | None in these sources |
| Basil | Small, 1–3 gal | Strong scent for youth gardens (DUG) | None in these sources |
| Mint | Small, 1–3 gal | Attracts pollinators; spreads aggressively, keep in a pot (UVM) | None in these sources |
| Marjoram | Small, 1–3 gal | Container herb (UMD) | None in these sources |
| Cilantro / coriander | Small, 1–3 gal | Draws beneficial insects (UVM); quick in spring or fall (DUG) | None in these sources |
| Garlic | Small, 1–3 gal | Container crop (UMD) | None in these sources |
| Rosemary | Medium, 4–6 gal | "Larger herb" (UMD) | None in these sources |
| Lavender | Medium, 4–6 gal | "Larger herb" (UMD) | None in these sources |
| Fennel | Medium, 4–6 gal | "Larger herb" (UMD) | None in these sources |
| Parsley | Medium, 4–6 gal | Draws beneficial insects (UVM) | Listed as toxic to chickens by NC State Extension (Richmond County) |
| Dill | — | Draws beneficial insects (UVM) | None in these sources |
| Borage | — | Pollinators and beneficials; spreads aggressively (UVM) | None in these sources |
| Chervil | — | Slug lure or deterrent (WSU; UVM "may") | None in these sources |
| Lemon verbena | — | "Very aromatic" (DUG) | None in these sources |
"—" means the source did not give a container class for that herb. Container classes are University of Maryland Extension's: small = 1–3 gallons and 4–6 inches deep; medium = 4–6 gallons and 8–12 inches deep. See the full container size table.
- Herbs in pots outside the run, so hens cannot scratch them up
- Small pots (1–3 gal): thyme, basil, mint, marjoram, cilantro
- Medium pots (4–6 gal): rosemary, lavender, fennel
- Run fence between birds and the herb bed
Growing herbs near a flock
- Separate plants and birds. Pots set outside the run, or a fenced herb bed, let the gardener decide what the flock reaches and when.
- Check the whole yard. NC State's list of plants toxic to chickens includes oleander, yew, castor bean, milkweed and tobacco. Its advice is to identify unknown plants in the landscape.
- Keep feed balanced. UMD notes that excessive table scraps "are not beneficial to birds or their productivity", and the same caution applies to any treat.
- Hygiene still applies. The CDC advises washing hands with soap and running water after touching backyard poultry.
For the basics of keeping hens, see backyard chickens: the short version.
Sources
- Alagawany et al. (2018), The usefulness of oregano and its derivatives in poultry nutrition, World's Poultry Science Journal 74(3)
- NC State Extension, Richmond County — Is Your Backyard Chicken Proof?
- University of Maryland Extension — Feeds and Feeding (small poultry flocks, PDF)
- University of Maryland Extension — Types of Containers for Growing Vegetables
- University of Vermont Extension — Creating a Biodiverse Vegetable Garden (PDF)
- Denver Urban Gardens — Plants for Youth Gardens (PDF)
- Washington State University Extension — Trap Cropping (PDF)
- U.S. Centers for Disease Control and Prevention — Backyard Poultry
All sources were opened and checked in October 2026. Rules and figures change; confirm with the original before acting.