Toxic Foods for Tortoises (Do NOT Feed These Foods)

Feeding the wrong foods can seriously harm your tortoise. While tortoises are hardy reptiles, their digestive systems are designed for high fiber, plant based diets, and certain vegetables, fruits, and plants can cause long-term health problems or even poisoning. This guide covers toxic foods for tortoises, common mistakes beginners make, and what to avoid to keep your tortoise safe and healthy.

Understanding what tortoises should avoid is just as important as knowing what they can safely eat. You can also read our guides on Can Tortoises Eat Apples, Can Tortoises Eat Bananas, and Can Tortoises Eat Pineapple to learn how fruit fits into a tortoise diet.

Short answer: Many common foods like avocado, onion, and dairy are toxic to tortoises and should never be fed.

For a complete diet guide, check out What Do Tortoises Eat

What Foods Are Toxic for Tortoises?

Toxic foods for tortoises include rhubarb, avocado, onions, garlic, and certain ornamental plants such as foxglove and oleander. These foods contain compounds that can interfere with calcium absorption, damage internal organs, or disrupt digestion. To keep your tortoise healthy, always avoid these high-risk foods and verify unfamiliar plants before offering them.

Vegetables Tortoises Should Avoid:

Not all vegetables are safe for tortoises. Some contain harmful compounds that interfere with calcium absorption, irritate the digestive system, or cause toxicity. Understanding which foods tortoise should avoid is critical for long term health.

Not sure if a specific food is safe for your tortoise? Check out these detailed guides:

Spinach

Spinach is high in oxalates which binds to calcium and doesn’t allow your tortoise to absorb calcium like it should. Think of it like locking up calcium. This can cause problems with shell grown, bone grown, and can even cause Metabolic bone disease or MBD.

Detailed Guide:  Can Tortoise Eat Spinach

Rhubarb

This is toxic to tortoises and should never be fed. IT has extrema levels of oxalates which not only disrupts calcium levels but also can cause kidney and organ failure.

Detailed Guide: Can Tortoises Eat Rhubarb

Avocado

This is toxic to tortoise and should never be fed. It contains a persin which can cause heart issues, respiratory distress, and even kill your tortoise. Avoid at all cost.

Detailed Guide: Can Tortoises Eat Avocado

Onions

Onions are harmful to tortoises and can damage their red blood cells. This can cause anemia or low blood cell count. It has no nutritional value and should not be fed.

Detailed Guide: Can Tortoises Eat Onions

Garlic

Garlic is similar to onions and harmful to tortoises. They cause damage to blood cells and should never be part of a tortoise diet.

Detailed Guide: Can Tortoises Eat Garlic

Mushrooms

These should be avoided to most tortoises. They can be toxic depending on the species and they can be hard to identify so its best to just avoid them. Some tortoises like my mountain tortoise eat them naturally but still one to avoid.

Detailed Guide: Can Tortoises Eat Mushrooms

Some vegetables are not toxic but still need to be fed carefully. Learn more in our guides on Can Tortoises Eat Spinach, Can Tortoises Eat Broccoli, and Can Tortoises Eat Cabbage to understand which vegetables should only be fed occasionally.

Fruits to Limit or Avoid:

Fruit is not always toxic, but it should be fed very sparingly. Most tortoise species thrive on high-fiber greens and weeds, not sugary fruits.

• Citrus Fruits– Citrus like lemons, oranges, grapefruits are all to acidic for tortoise and can upset their digestive system and gut balance. The high acidity can also cause mouth irritation. I avoid them, even though some species can have them.
• Bananas– Bananas are high and sugar and has way to much moisture for most tortoises. This can cause digestive problems and gut imbalances. I use them as a treat mixed into food but this is very occasionally.
• Grapes– Like bananas grapes also have high sugar content and moisture. This can lead to digestive tract issues, and gut imbalances. I rarely feed them but if I do they are just treats.
• Excess Fruit in General- Fruit is not toxic to tortoises its just not good for them when fed to much. IT can cause digestive imbalances, diarrhea, and long term health issues. Most species should only be fed fruit as a treat to stay away from the high sugar content.

Fruits like strawberries, bananas, and grapes are not toxic but should only be offered occasionally because of their sugar content.

Detailed Guides Below:

• Can Tortoises Eat Citrus Fruits
• Can Tortoises Eat Strawberries
• Can Tortoises Eat Bananas
• Can Tortoises Eat Grapes

Quick Toxic Food Reference Table:

Toxic Plants & Weeds:

Tortoises kept outdoors may graze naturally, but not all garden plants and weeds are safe. Many ornamental plants and wild flowers can be toxic if eaten.

• Buttercup– Toxic to tortoises and can cause mouth irritation, drooling and upset stomach if eaten.. It should be removed from enclosure and avoided as much as possible.
• Foxglove– Highly toxic to tortoises that affects the heart. This can cause potential serious illness and death if ingested. Tortoises should never be offered or have access to this plant.
• Daffodil– These are poisonous to tortoises. The whole plant is poisonous but the bulbs are especially potent. This plant can cause vomiting, diarrhea, and severe health issues. Keep it out of enclosures and out of reach of tortoises.
• Azalea– This plant contains toxins that can affect the nervous system and digestive tract. This should be avoided even in small amounts.
• Ivy– Is toxic and can irritate a tortoises mouth and digestive system. It shouldn’t be in a tortoises enclosure or in reach during grazing.
• Oleander– This is extremely toxic. IT affects the heart and can cause death even in the smallest amount. Be sure your tortoise never has access to this plant.

If you allow your tortoise to graze outdoors, always research any plant in the enclosure before assuming it is safe.

Many tortoises naturally graze on weeds and plants outdoors, but not all plants are safe. Some excellent natural foods include dandelion greens, grasses, and hibiscus, which you can learn more about in our guides on Can Tortoises Eat Dandelions, Can Tortoises Eat Grass, and Can Tortoises Eat Hibiscus.

Why some food are dangerous:

Tortoises are designed to eat high-fiber, low-sugar vegetation. When they consume inappropriate foods, several problems can occur:

• Oxalates Binding to Calcium– Some foods contains oxalates which bind to calcium preventing your tortoise from absorbing calcium properly. Over the long term this can lead to calcium deficiency and even more serious issues like metabolic bone disease. Some greens such as spinach and kale contain high levels of oxalates and should only be fed in moderation.
  • Can Tortoises Eat Spinach
  • Can Tortoises Eat Kale
• High Sugar Disrupts Gut Health– High sugary food can upset a tortoises digestive system and harm the beneficial bacterial in their gut. This can diarrhea, poor digestion and in the long term health issues due to nutrient deficiency.
• Toxic Compounds Affect Liver & Kidney– Some plants have toxic compounds that are naturally found and can cause damage to a tortoise liver, kidneys and other organs. They can range in levels of toxicity and even small amounts can cause serious illness or death.
• Tortoises Need High-Fiber Diets– Tortoises have evolved and adapted to eat a high fiber diet. Plants like grasses, weeds, and flowers. Try to avoid sugary diets and other plants that contain high oxalates or toxins.

What to Do If Your Tortoise Eats Something Toxic:

If your tortoise consumes a potentially toxic food or plant:

• Remove Access– Immediately identify and remove the toxic food or plant from the enclosure to prevent any further ingestion. Check the enclosure or area carefully for any more that can be accessible.
• Monitor Behavior– It is important to monitor and watch closely if your tortoise is showing any behavior changes. Loss of appetite, lower activity levels are all examples of illness and can appear in minutes or hours.
• Contact Reptile Vet– If you believe your tortoise has eaten something toxic please contact a vet that works with reptiles. The sooner you contact a vet the more critical it can be for a full recovery.
• Watch for Symptoms– Symptoms like lethargy, diarrhea, swelling, vomiting, or difficult breathing are serious and require to seek veterinary care immediately!

If you’re trying to build a healthy diet for your tortoise, it also helps to understand the foods they should eat regularly. Check out our full guide on What Do Tortoises Eat for a complete overview of staple greens, weeds, and safe foods.

FAQ Section:

What is next?

If you’re new to tortoise keeping, start with our Beginner’s Guide to Tortoise Care before choosing your species.

• Full Care Guide → /care-guides/
• Diet & Nutrition → /diet/
• Habitat & Enclosures → /habitat/
• Gear Reviews → /gear-reviews/

Continue building your tortoise’s diet:

• Best Weeds for Tortoises to Eat
• Best Leafy Greens for Tortoises
• Best Vegetables for Tortoises
• Best Fruits for Tortoises