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Yes, chickens can eat ripe tomatoes as an occasional treat; it is the leaves, stems and green, unripe fruit that contain much higher levels of the glycoalkaloid tomatine. Documented poisoning from tomato plants is rare, but there is no reason to feed the risky parts. This guide explains where tomatine is found and how to share tomatoes with your flock sensibly.
Key Takeaways
- Ripe red tomatoes contain very little tomatine, about 5 mg per kg of fruit.
- Immature green tomatoes can contain up to 500 mg per kg.
- Tomatine is found in all parts of the plant, including leaves and stems.
- Treats such as tomatoes should stay under about 10 percent of the diet.
- Never feed rotting or moldy scraps.
Correction: an earlier version of this article described a tomatine poisoning syndrome in chickens with vomiting, seizures and hemolytic anemia, included a fabricated table of mild and severe cases, and claimed that cooking or fermenting tomatoes neutralizes tomatine; these claims were unsupported and have been removed.
What tomatine is and where it is found
Tomatine is a glycoalkaloid, a natural defense compound that tomato plants make. A 2023 review in the journal Molecules notes that tomatine and a related compound, dehydrotomatine, are present in all parts of the tomato plant: fruit, flowers, leaves, stems, calyxes (the green caps) and roots.
The amount in the fruit drops sharply as it ripens, because the plant breaks tomatine down enzymatically.
| Plant part | Tomatine level |
|---|---|
| Immature green fruit | Up to about 500 mg per kg fresh weight |
| Ripe red fruit | About 5 mg per kg fresh weight |
| Leaves and stems | Listed by NC State Extension as the toxic parts of the plant |
How risky are tomato plants for chickens?
NC State Extension rates tomato as a medium-severity poison and says leaves and stems can cause stomach upset and other effects if eaten in large quantities. It also notes that the Carolinas Poison Center has recorded very few actual cases of harm from tomato leaves.
There is little published information on tomatine in chickens specifically, and no reliable list of chicken symptoms. The practical answer is simple: ripe fruit is fine in moderation, while leaves, stems and green fruit are not worth the risk.
How to feed tomatoes safely
- Use ripe, red (or fully colored) tomatoes, cut into pieces.
- Remove the green calyx and any green, unripe sections.
- Keep chickens out of the vegetable patch while tomato plants are growing, or fence the plants. See how to keep chickens out of the garden.
- After harvest, pull and compost vines where the flock cannot reach them.
- Feed only fresh produce. Extension guidance warns not to let scraps rot, as rotting food can lead to botulism.
How much is too much?
Tomatoes are a treat, not a meal. The University of Illinois College of Veterinary Medicine advises that scratch grains, leafy greens and vegetables make up no more than 10 percent of a chicken’s diet. Poultry extension guidance adds that table scraps and scratch should be no more than the birds can finish in about 20 minutes, and that too many scraps and greens can reduce egg production.
The reason is balance. Commercial layer and grower feeds are formulated as complete diets, and Mississippi State University Extension notes that feeding other ingredients alongside a complete feed upsets its balance of nutrients. A few tomato pieces are fine; a bowl of garden surplus every day is not.
The main diet should be a complete feed suited to the birds’ age. For more on balancing treats, see can you overfeed chickens and our chicken feed guide.
If your chickens ate tomato leaves or green tomatoes
A few pecks at leaves or a fallen green tomato are unlikely to cause problems. Remove access to the plants and watch your birds. If a chicken becomes quiet, stops eating, or has persistent diarrhea, call a veterinarian, and remember that these signs have many causes besides diet.
A plant poisoning does not spread between birds, but moving a sick bird to a quiet pen makes it easier to watch its eating and droppings.
When the problem is not the tomatoes
It is easy to blame the last thing a chicken ate, but many illnesses look similar at first. USDA lists warning signs that point to serious infectious disease rather than diet:
- Sudden deaths or several sick birds at once
- Swelling of the head, eyelids, comb, wattles or shanks
- Purple discoloration of the comb, wattles or legs
- Gasping, sneezing or nasal discharge
- Greenish, watery diarrhea or a sharp drop in egg production
If you see these signs, report sick or dying birds to your state veterinarian or USDA at 1-866-536-7593.
FAQs
Can chickens eat green tomatoes?
It is best not to feed them. Immature green tomatoes can contain up to about 500 mg of tomatine per kg, around a hundred times more than ripe red fruit.
Can chickens eat tomato leaves and vines?
No. Leaves and stems contain tomatine and are listed as the toxic parts of the plant. Keep chickens away from tomato plants.
Does cooking make green tomatoes safe for chickens?
There is no good evidence that cooking makes green tomatoes or tomato plants safe for chickens, so stick to ripe fruit.
Can chickens eat rotten or moldy tomatoes?
No. Feed only fresh produce. Poultry extension guidance warns that scraps left to rot can lead to botulism.
How often can I give my chickens tomatoes?
Tomatoes can be part of the treat allowance a few times a week, as long as all treats together stay under about 10 percent of the diet and the flock finishes them within about 20 minutes.
Conclusion
Ripe tomatoes make a fine occasional treat for chickens, while the leaves, stems and green fruit carry far more tomatine and should be avoided. Keep treats to a small share of the diet and feed only fresh, ripe produce.
Sources
- PMC: Friedman et al. 2023, Isomers of the Tomato Glycoalkaloids alpha-Tomatine and Dehydrotomatine (Molecules)
- NC State Extension Gardener Plant Toolbox: Solanum lycopersicum
- Poultry Extension: Feeding Chickens for Egg Production
- University of Illinois College of Veterinary Medicine: Care and Feeding of Backyard Chickens
- USDA APHIS: Signs of Illness in Poultry
- Mississippi State University Extension: Feeds and Nutrition
Checked September 2026. Labels change, so always read the label on the product you buy. See our editorial policy for how we research health articles.
