In recent years, commercial egg production systems have joined the drive for alternatives to chemicals, in order to ensure the health and wellbeing of flocks.
This concentration on developing natural methods has resulted in excellent studies of the impact of herbs for chicken health and improved egg quality.
This article takes ten of the best and most easily grown herbs, and reviews each one based on those properly researched studies.
You will find a full list of resources at the end of this article for further reading.
It looks at the impact of each, its vitamin and mineral levels, which specific conditions it can help treat and, importantly, how each one should be fed to chickens and in what quantities to achieve the maximum possible benefit.
It's an inexpensive and fun way of making sure your chickens are getting the healthiest natural additives to their feed.
Bear in mind, though, that too much of anything is not good for your flock. Everything in moderation is key – even with natural produce.
Important note:
I am not a veterinarian, and this information does not constitute veterinary advice.
If your chickens seem unwell, or if you're at all worried about your chickens and how to treat them, you should consult your nearest avian veterinarian.
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Use these links to jump to the one you want – or carry on reading about them all.
Basil is one of the easiest herbs to grow, one of the healthiest for chickens, one of the best for keeping flies away from the coop, and one of the easiest to feed to your flock(1).
Basil's claim to chicken fame: known to increase antibodies to fight Newcastle disease.
General: specifically in terms of herbs for chicken health, basil has been proven(1) to...
Vitamin and mineral content:
Other uses:
Summer: best fed in fresh bunches during the growing season.
Winter: pick fresh leaves and dry them in a dehydrator or oven. Crumble the dried basil over food at the rate of about 3 – 5 grammes (0.1 oz) to one kilo (2.5lb) of feed.
There's no researched evidence that chamomile will send your chickens to sleep!
It's easy to grow from seed as part of your lawn, or for faster coverage buy young plants from your local supplier.
Chamomile's chicken claim to fame: it's proven to be one of the best ways of helping eliminate Salmonella(2).
General: specifically in terms of chicken health, chamomile has been proven(2) to...
Vitamin and mineral content:
The easiest way to feed this herb to your flock at any time of year is by making a chamomile tea.
Pick the flowers when they're young. Steep them in hot water for ten minutes. Strain, allow the water to cool, and offer to your flock in a shallow dish.
Not a herb you necessarily think of having as a staple in the garden, but it's easy to grow and its seeds are a bonus for your flock.
Dill's chicken claim to fame: if you have a chicken who's gone off their feed, try offering some dill seeds in amongst the grain.
Also an effective treatment against E-coli.
General: specifically in terms of chicken health, dill has been proven(3) to...
Vitamin and mineral content:
Planting this herb in your chicken run is fine – the flock can peck at the feathery leaves if that's what catches their eye.
However, studies showed that using dill seeds added to everyday chicken feed was both simple and showed a more significant change in health than other parts of the plant.
Add at the rate of about one teaspoon per kilo (2.4lbs) of chicken feed.
Have you read that garlic is a member of the onion family and therefore poisonous to chickens?
Not so!
It's one of the most widely researched herbs in terms of chicken health, and proven beyond doubt to be beneficial to their wellbeing.
Garlic's chicken claim to fame: proven to be active against bacteria including Salmonellosis, Colibacillosis and Cholera(4).
And no, fed in the right amounts it won't make eggs taste of garlic!
General: the benefits of garlic are so many that I have an entire article dedicated to it. There you will find a list of everything it can help with.
In particular, if you have a chick or chicken which is generally weak and seems to be failing, take a look at the article for detailed information.
Find the article about the benefits of garlic for chickens here.
It's proven that crushed, fresh garlic is the most beneficial way of feeding garlic to chickens(4). Mixing it with feed can be difficult, since its moisture can promote mould, so adding it to water is the best method.
For details and measurements, see this page.
Yes – but – not any mint.
Research has shown that peppermint is the most effective of the mint herbs for chicken health.
Not only easily grown but invasive unless controlled, it's worth having a pot of mint in your chicken run. Keeping its roots confined prevents it spreading everywhere!
Its chicken claim to fame: proven to increase the strength of egg shells in laying hens(5).
General: specifically in terms of herbs for chicken health, peppermint has been proven(5) to...
Vitamin and mineral content:
Please note: too much iron is toxic for chickens, so as with all herbs feed in moderation and do not go over the advised dosages.
A powerful antibiotic, Oregano is now used in many commercial poultry farms as an alternative to chemicals to help guard against disease.
Oregano's chicken claim to fame: a good antidote following a predator attack.
General: specifically in terms of chicken health, oregano has been proven(6) to...
Vitamin and mineral content:
Oil of Oregano:
Flat-leafed parsley is scientifically proven to have a much higher concentration of essential oils in its leaves.
So if you're going to feed parsley to your flock, make sure it's the flat-leaved variety.
Parsley's claim to chicken fame: high levels of vitamin 'C', critical for supporting the immune system, particularly in cold weather. Described as an “immune enhancing multi-vitamin”(7).
General: the benefits of parsley are so many, and it's so easy to grow, that I have an entire article dedicated to it. There you will find a list of everything it can help with.
Read my article about feeding parsley for chicken health.
Vitamin and mineral content:
See this article for detailed information about feeding parsley to chickens.
It grows well in sun, needs little watering once established, and is useful in human cooking as well as for chicken wellbeing.
Rosemary's claim to chicken fame: if you find your chickens develop Bumblefoot, try using rosemary to help treat and prevent it.
General: specifically in terms of chicken health, rosemary has been proven(8) to...
Vitamin and mineral content:
Sage is used in both commercial and backyard chicken care because of its ability to counteract the impact of free radicals on cells and help prevent bacteria and mould causing disease.
Sage's claim to chicken fame: decreases the amount of damaging cholesterol levels in eggs.
General: specifically in terms of herbs for chicken health, sage has been proven(9) to...
Vitamin and mineral content:
One of the best sources of phytonutrients, vitamins and minerals(10).
Thyme's claim to chicken fame: lowers rates of the E.coli bacteria.
General: specifically in terms of chicken health, thyme has been proven(10) to...
Vitamin and mineral content:
All this information is taken from reliable, scientific, peer-reviewed research. These are a few of the resources I’ve used for this list, in alphabetical order by herb.
1. Basil: Jahejo, A. R, et al: Immunomodulatory and Growth Promoting Effects of Basil (Ocimum basilicum) and Ascorbic Acid in Heat Stressed Broiler Chickens. Pub. Journal of Zoology, 2019.
2. Chamomile: Abd El Hack et al: Chamomile: functional properties and impacts on poultry/small ruminant health and production – A Review. Pub. Annals of Animal Science, 2023.
3. Dill: Rahimian, Y et al: Effect of using different levels of Dill seeds on performance, some blood biochemical and intestinal microbial population in broiler chicks. Pub. Journal of Herbal Drugs, 2017.
Magnesium requirements: Shastak, Y et al: A review of the role of magnesium in poultry nutrition. Pub. Journal of Poultry Science, 2015.
4. Garlic: Olobatoke, R., and Mulugeta, S.: Effect of dietary garlic powder on layer performance, fecal bacterial load and egg quality. Pub. Poultry Science, 2011.
Rehman, Z., and Munir, M: Effect of garlic on the health and performance of broilers. Pub. Veterinaria, 2015.
5. Mint: Abdel-Wareth, A., and Lohakare, J.: Effect of dietary supplementation of peppermint on performance, egg quality, and serum metabolic profile of Hy-Line Brown hens during the late laying period. Pub. Journal of Animal Feed, Science and Technology, 2014.
Asadi, N., et al: Performance of Broilers Supplemented With Peppermint (Mentha piperita L.) Powder. (Journal of Evidence Based Complementary and Alternative Medicine, 2017).
6. Oregano: Migliorini, Marcos J et al. "Oregano essential oil (Origanum vulgare) to feed laying hens and its effects on animal health." Pub. Anais da Academia Brasileira de Ciencias, 2019.
Ruen et al: Effects of dietary oregano essential oil supplementation on growth performance, intestinal antioxidative capacity, immunity, and intestinal microbiota in yellow-feathered chickens. Pub. Journal of Animal Science, 2021.
El-Gazzar, M: Listeriosis in Poultry. Pub. MSD Veterinary Manual, 2024.
7. Parsley: Nihad, D: Effect of Additional Different Level of Parsley Leaves (petroselinum sativum) Powder to the Ration on Some Blood Serum Biochemical Traits of Broiler Chickens. Pub. Journal of Natural Sciences Research, 2016.
Al-Dharaji, H, et al: The Influence of Parsley (Petroselinum crispum) as Feed Additive on Hematological Traits of Local Iraqi Geese. Pub. Advances in Nutrition Research, 2012.
8. Rosemary: Ghanima, A, et al: Effect of housing system and rosemary and cinnamon on layers’ performance, egg quality, haematological traits, blood chemistry, immunity and antioxidant. Pub. Animals Journal, 2020.
9. Sage: Rasouli, B, et al: Effect of sage (Salvia officinalis L.) aqueous leaf extract on performance, blood constituents, immunity response and ileal microflora of broiler chickens. Pub. Agroforestry Systems, 2020.
Galamatis, D., et al: Effects of Dietary Supplementation of Salvia officinalis L. in Organic Laying Hens on Egg Quality, Yolk Oxidative Stability and Eggshell Microbiological Counts. Pub. Animals: an Open Access Journal, 2021.
10. Thyme: Bolukbasi, S. C.: Effect of dietary thyme on laying hens’ performance and e.coli concentration in feces. Pub. International Journal of Natural and engineering Sciences, 2006.
Halat, D., et al: A Focused Insight into Thyme: Biological, Chemical, and Therapeutic Properties of an Indigenous Mediterranean Herb. Pub. Nutrients, 2022.
11. Vitamin Requirements: Poultry DVM.
12. General: Bloom, Jessi: Free Range Chicken Gardens. Pub. Timber Press.