Tortoises naturally inhabit many regions across the World from the Sahara Desert region of Africa, the rainforests and deserts of Asia, the Mediterranean region of Europe, as well as desert regions in North America and the Amazon Basin in South America.
This global distribution showcases the adaptability of tortoises and highlights how specific climates and terrains greatly influence each species’ dietary needs.
For this reason, it is vitally important for owners and keepers to understand their tortoise’s natural habitat and be able to replicate a diet that is appropriate to their physiological and metabolic needs.
In this article I shall be sharing my insights into what tortoises can and can’t eat, plus when and how often they should be fed, depending on age.
Dietary Needs
Vegetation is the primary source of nutrition for wild tortoises, where 95% of the time they graze on a wide range of grasses, weeds, hay, and other plant materials.
This diet is low in fat and protein but high in fiber, which is critical for their digestive health.
In their natural habitat, tortoises encounter diverse foraging options, and this variety provides essential vitamins and minerals, which is fundamental to bone and shell health, and effective autoimmune functioning.
Calcium and Phosphorus are critical for maintaining their overall health, particularly the health of their bones and shell.
The correct ratio of these minerals is vital because it affects how efficiently calcium is absorbed and utilized in the body, which in turn influences bone density and structural integrity.
The ideal dietary calcium to phosphorus (Ca:P) ratio for tortoises should be between 1.5:1 and 2:1. This means that there should be at least 1.5 to 2 times as much calcium as phosphorus in their diet.
Calcium is essential for the development and maintenance of strong bones and a healthy shell. Phosphorus, on the other hand, while also essential, competes with calcium for absorption in the digestive tract.
When phosphorus levels are too high relative to calcium, it can inhibit the amount of calcium absorbed and lead to deficiencies.
Adequate calcium is necessary for proper bone mineralization. Without it, tortoises can develop metabolic bone disease, which results in soft, deformed shells (a condition known as pyramiding) and weakened bones that are prone to fractures.
Calcium also plays a role in nerve function, blood clotting, and muscle contraction. An imbalance in the Ca:P ratio can lead to other health issues, including kidney disease, due to the body mobilizing calcium from bones to maintain necessary blood levels, leaving the bones depleted.
To maintain a healthy Ca:P ratio, your tortoise requires foods that are naturally high in calcium and low in phosphorus. Leafy greens such as dandelion, mustard, and turnip greens are excellent choices.
Avoid excessive use of foods like spinach and beet greens, which have high phosphorus levels or substances that inhibit calcium absorption.
Water is also vital for the health and survival of tortoises. Without regular ingestion and soaking, they are unable to stay hydrated, regulate their body temperature, or facilitate digestion.
Fruits are not a major part of a tortoises natural eating habits and may only be encountered seasonally, opportunistically, and for most desert species, not at all. This adaptation means that tortoises are not tolerant to the high sugar content in fruit, and therefore in captivity it should be offered sparingly to prevent digestive issues.
Protein is a contentious topic in the dietary regimen of tortoises, as excessive amounts can lead to detrimental health conditions like shell deformities and kidney problems.
For most species, the natural diet comprises predominantly vegetation, with protein sources being extremely limited. In their natural habitat Gopher tortoises are known to eat occasional carrion when opportunity knocks and some Forest species including the Asian Forest tortoise are known to eat invertebrates on occasion.
Safe and Nutritious Foods for Tortoises
When it comes to dietary requirements, it won’t surprise you to learn that a tortoise’s native home has a lot to do with what they need to eat in captivity to thrive.
To capture the nuances of their diet, I have broken this section down into tortoise types, and then a list of food stuffs that are safe for them to eat.
Desert Tortoises
In their natural habitat, desert tortoises including Russian tortoises and Sulcata, live in dry regions with sparse vegetation.
These arid conditions mean they are adapted to primarily consuming a diet rich in native grasses and plants that provide both nutrition and necessary water content.
| Food Category | Variety | Notes |
| Grasses | Bermuda Grass | Grows well in hot climates and provides good fiber content which is crucial to digestive health. |
| Buffalo Grass | A drought-resistant grass that offers a good balance of nutrients. | |
| Blue Grama | Native to the American West and well-suited for tortoises due to its nutritional profile and availability in desert environments. | |
| Desert Bunch | Native to arid regions and naturally part of the desert tortoise’s diet in the wild | |
| Hay | Timothy Hay | Not a native desert plant, but suitable and widely recommended hay due to high fiber and low protein content. |
| Orchard Grass | Softer than Timothy hay and a good alternative if Timothy is unavailable | |
| Alfalfa Hay | Beneficial to juveniles but offer sparingly as it contains high protein and calcium. | |
| Leafy Greens | Dandelion Greens | High in calcium and vitamin K, excellent for shell health. |
| Turnip Greens | Rich in nutrients and low in oxalates. A great option when offered as part of a varied diet. | |
| Mustard Greens | Offer in moderation due to higher vitamin A content. | |
| Endive | Adds variety and won’t cause digestive issues compared to more fibrous greens. | |
| Collard Greens | A staple that’s high in calcium and fiber, suitable for regular feeding. | |
| Vegetables | Carrots | Contains beta-carotene, which is good for shell and skin health. Serve shredded or finely chopped. |
| Squash | Can be fed raw or cooked, providing vitamins and a different texture for dietary enrichment. | |
| Bell Peppers | High in vit A and C. Offer in moderation. | |
| Cucumber | Not nutrient-dense, but hydrating. Offer as an occasional treat. | |
| Broccoli | Offer sparingly due to possible gas which can interfere with thyroid function if fed in large quantities. | |
| Cauliflower | Same as broccoli. | |
| Zucchini | High water content provides hydration, but should be part of a broader diet to avoid loose stools. | |
| Fruit | Strawberries | Contain vitamin C, but offer sparingly due to sugar content. |
| Cantaloupe | Hydrating and full of vitamins, offer small pieces occasionally. | |
| Papaya | Excellent source of vits and enzymes that can aid digestion if given occasionally. | |
| Apple | Low in calories and high in fiber. Remove seeds and serve in small pieces to avoid choking. | |
| Flowers | Hibiscus | Both the flowers and leaves are safe. A tortoise favourite. Offer as part of a varied diet. |
| Rose petals | Ensure they are free from pesticides and offer as part of a varied diet. | |
| Nasturtium | Both flowers and leaves are edible, offering a good source of vitamin C. | |
| Dandelion flowers | Nutrient-rich and typically safe to pick from areas free of chemical treatment. | |
| Mint | Offer sparingly for its digestive benefits. | |
| Basil | Safe in small amounts, providing a good source of vitamins. |
You’ll need to incorporate a variety of leafy greens as they are high in calcium and other nutrients. I tend to mix these up, so they are not eating too much of one variety.
I also include vegetables such as carrots and squash as these have low water content and further add variety and nutrients. Desert tortoises only need to consume these in moderation – typically every other feed.
Since fruit does not form part of a Desert tortoises’ typical diet, I offer these as a very occasional treat. It’s difficult to resist the temptation as they love the sweetness of melons, berries and apples, but it’s not great for their digestion and so I only tend to offer it when in season and if I have an abundance in my fruit bowl.
Forest Tortoises
In their natural habitat, Forest tortoises, such as the Red-footed and Yellow-footed tortoise, live in dense, humid forest environments.
These lush conditions provide a rich variety of vegetation and small animal proteins, which are crucial for their nutrition and hydration needs.
| Food Category | Variety | Notes |
| Leafy Greens | Hosta | Common in forest floors, rich in moisture and nutrients. Feed occasionally. |
| Ferns | Common in forest floors. | |
| Bromeliad | A tropical plant that is common to tropical forest environments. All parts of the plant can be eaten. | |
| Lipstick Plant | Both leaves and flowers can be consumed by tortoises. | |
| Dandelion | High in calcium and vitamin K, excellent for shell health. | |
| Turnip Greens | Rich in nutrients and low in oxalates. A great option when offered as part of a varied diet. | |
| Hibiscus leaves | (Flowers are safe too) | |
| Cactus Pads | Minced or chopped into pieces. | |
| Collard greens | Low oxalate content but feed in moderation rather than regularly. | |
| Kale | Offer occasionally as part of a varied diet. | |
| Vegetables | Mushrooms | Mushrooms are abundant in forests but feed occasionally. |
| Squash | Winter varieties and pumpkin. Cut into small pieces. | |
| Turnip | Low oxalate content but feed in moderation rather than regularly. | |
| Okra | Calcium rich but high in oxalates so feed occasionally. | |
| Carrots | Adds necessary beta-carotene as part of a varied diet. | |
| Fruits | Figs | High moisture and nutrient content; should be given in moderation due to sugar content. |
| Melon | All varieties. Cut into small pieces including rind. | |
| Plantain | Provide essential vitamins and are naturally part of their diet in forested areas. | |
| Berries | Abundant in forests and small enough to be consumed without cutting up. | |
| Apples | High in fiber. Remove seeds and serve in small pieces to avoid choking. | |
| Protein | Snails | Occasional consumption reflects opportunistic feeding habits in the wild. |
| Worms | Feed occasionally as part of a diet rich in low calorie / high fiber vegetables and some fruit. | |
| Calcium | Cuttlebone | Important for shell and bone health, should be supplemented regularly. |
| Flowers | Hibiscus | Edible and high in nutrients. Provides variety and enrichment. |
| Orchid | Ensure they are pesticide free. Probably a rare treat for tortoises! | |
| Pansies | Look great in a tortoise enclosure and ideal for them to eat provided they are free from pesticides. |
Forest tortoises thrive on a variety of lush, moisture-rich leafy greens which are abundant in their natural habitats. These greens provide the necessary fiber and water content that aids in their digestion and overall health.
In a forest environment, fruits like figs and berries are widely available, albeit seasonally. These should be incorporated into a captive tortoise’s diet in moderation as although they provide essential vitamins, they are also high in sugars.
Similarly for animal protein, Forest tortoises occasionally consume small numbers of worms, snails and invertebrates, which provide natural calcium and other minerals. These should be given to captive tortoises as an occasional treat to reflect their opportunistic feeding behavior.
To encourage natural foraging behaviors and enrichment, you might want to plant a bed of wild herbs or flowers in your pets enclosure. These are typically found in the underbrush of forest areas and therefore mimic their natural habitat.
Mediterranean Tortoises
Hermann’s, Greek, and Marginated are Mediterranean tortoise species who, in the wild, thrive on a diet largely composed of leafy greens and flowers, with a strong emphasis on fiber.
In captivity, these animals need a diet that closely mimics what they’d typically graze on in the wild. As follows:
| Food Category | Variety | Notes |
| Leafy Greens | Dandelion | High in fiber and calcium, staple foods that should dominate the diet. |
| Endive | Feed as part of a varied diet. | |
| Rocket | Contains goitrogens so feed in moderation. | |
| Turnip Greens | Rich in nutrients and low in oxalates. A great option when offered as part of a varied diet. | |
| Mustard Greens | Offer in moderation due to higher vitamin A content. | |
| Weeds | Plantain | Nutrient-rich and commonly found in their natural habitat. Fine to feed regularly. |
| Clover | Contains protein so feed sparingly as part of a varied diet. | |
| Chickweed | Feed in moderation. | |
| Flowers | Hibiscus | Flowers and leaves are edible and provide variety and vitamins. |
| Rose petals | A delicious treat for tortoises when available. Ensure they are free from pesticides. | |
| Nasturtium | Feed in moderation due to high oxalate content. | |
| Vegetables | Carrot tops | Offer in moderation; high in vitamins but lower in fiber. |
| Zucchini | Flowers and fruit are fine. Avoid leaves and stem. High water content so avoid excessive amounts. | |
| Bell peppers | Feed occasionally due to poor calcium to phosphorous ration. Fruit only – avoid leaves, root and stem as this is toxic to tortoises. | |
| Fruits | Apple | De-seed and cut into small pieces. |
| Melon | Only occasionally due to high sugar content. | |
| Calcium | Cuttlebone | Essential for shell and bone health. |
Low calorie and high fiber leafy greens and weeds should form the core of the Mediterranean tortoise’s diet, and adding edible flowers introduces natural antioxidants and vitamins, and can enhance dietary enrichment.
While nutritious and good for adding variety and additional hydration, vegetables should be given in moderation to prevent potential digestive issues.
Likewise, fruits, with their high sugar content, should be offered sparingly. Small pieces of apple or melon can be a treat, but there use should be limited to avoid digestive issues.
Finally, regular supplementation with calcium is crucial to prevent shell deformities and promote overall skeletal health. Cuttlebone is a great option as tortoises can self-regulate their intake.
Foods to Avoid
When planning a diet for your tortoise, it’s just as important to know which foods to avoid as it is to know what to include.
Some foods can be harmful or even fatal to tortoises due to the presence of toxins, excessive amounts of certain nutrients, or compounds that tortoises cannot digest properly.
For example, anything that contains oxalic acid is a big no because it binds with calcium and prevents its absorption, potentially leading to metabolic bone disease—a serious condition in tortoises.
Anything containing goitrogens can disrupt thyroid function, and solanine is a toxin found in nightshade plants that affect a tortoises’ nervous system. For a comprehensive list of tortoise safe plants, click here.
In the section below, I’ve provided a list of commonly grown plants and vegetables which should be avoided. I’ve outlined why these foods are harmful and what specific substances they contain that pose a risk to your pet’s health.
Flowers
| Autumn Crocus (Colchicum autumnale) | Highly toxic as it contains colchicine, which can cause gastrointestinal distress and multi-organ damage. |
| Buttercup (Ranunculus spp.) | Contains ranunculin, which can cause irritation and gastrointestinal problems. |
| Daisy (Common or Lawn) | Contains saponins and tannins both of which are harmful to tortoises, although small amounts won’t harm. |
| Foxglove (Digitalis purpurea) | Contains digitalin, which is toxic to the heart. |
| Hemlock (Conium maculatum) | Extremely toxic; contains coniine, which can disrupt the nervous system and lead to death. |
| Lantana (Lantana camara) | Toxic to tortoises due to its pentacyclic triterpenoids, causing liver damage and failure. |
| Lupine (Lupinus spp.) | Contains alkaloids that can be harmful to tortoises. |
| Morning Glory (Ipomoea spp.) | Contains lysergic alkaloids which can cause neurological issues. |
| Oleander (Nerium oleander) | Extremely poisonous, containing compounds that can cause severe cardiac issues. |
| Rhododendron (Rhododendron spp.) | Contains grayanotoxins that can affect cardiac function and cause gastrointestinal upset. |
| Yew (Taxus spp.) | Contains taxine, a compound that is highly toxic to both human and animal cardiac systems. |
Plants
| Alocasia | Contains oxalate raphide crystals, which if ingested can cause irritation in the throat, tongue, mouth, and stomach. Can also lead to difficulty in breathing. |
| Caladium (Caladium spp.) | leaves contain calcium oxalate crystals that can lead to oral irritation and digestive upset. |
| Crocus (Crocus spp.) | Can cause stomach upset and vomiting, while the Autumn Crocus (Colchicum autumnale) is highly toxic and should be avoided at all costs. |
| Daffodil | All parts contain the alkaloid lycorine and are therefore toxic to tortoises. Can cause vomiting, diarrohea and convulsions. Also known to damage the nervous system and paralyse the heart. |
| Dieffenbachia (Dieffenbachia spp.) | Contains calcium oxalate crystals, causing intense oral irritation and swelling. |
| Dumb Cane (Dieffenbachia spp.) | Highly toxic due to calcium oxalate crystals; ingestion can lead to severe swelling and burning of the mouth and throat. |
| Euphorbia | Contain a carcinogenic toxin. The milky sap can cause inflammation of the skin and mucous membranes of the eyes, nose and mouth. |
| Grape Hyacinth | Contains comisic acid, which can cause diarrhoea and sickness. |
| Ivy (Hedera spp.) | Contains saponins, which can cause vomiting, abdominal pain, and hypersalivation if ingested. |
| Jade Plant (Crassula ovata) | Contains compounds that can cause nausea, vomiting, and a slow heart rate in tortoises. |
| Peace Lily (Spathiphyllum spp.) | contains calcium oxalate crystals, causing similar symptoms as Dieffenbachia. |
| Philodendron (Philodendron spp.) | Contains calcium oxalate crystals that can cause oral irritation, difficulty swallowing, and gastrointestinal distress. |
| Pothos (Epipremnum aureum) | Contains insoluble calcium oxalates which are toxic and can cause oral and gastrointestinal irritation. |
| Sago Palm (Cycas revoluta) | Contains cycasin, which is toxic to the liver and can be fatal if ingested. |
Grasses and Ferns
| Asparagus Fern (Asparagus setaceus) | Not a true fern, but often grouped with them. It contains sapogenins that are irritating and toxic if ingested. |
| Bracken Fern (Pteridium aquilinum) | Contains thiaminase, which breaks down thiamine (vitamin B1), leading to severe neurological disorders. |
| Foxtail Grass | Not inherently toxic, but its barbed seed heads can cause physical injury to tortoises, leading to infections or digestive tract obstructions. |
| Johnson Grass (Sorghum halepense) | Another Sorghum species that is toxic due to the same compounds. |
| Sorghum | Contains cyanogenic glycosides, which can release cyanide when damaged, posing a risk of poisoning. |
| Sprengeri Fern (Asparagus densiflorus ‘Sprengeri’) | Another asparagus fern that contains toxic compounds similar to the Asparagus Fern, causing irritation and potential poisoning. |
| Sudan Grass | A variety of Sorghum, also contains harmful cyanogenic glycosides. |
Fruits
| Avocado | Contains persin, which is highly toxic to many animals, including tortoises, and can cause heart damage and other serious health issues. |
| Citrus Fruits | The sugar and acid in citrus fruits are known to cause digestive issues and vomiting and diarrhoea. |
| Pomegranate | Contains tannins which can inhibit the absorption of iron if too much is ingested. |
| Rhubarb | Contains oxalic acid and anthraquinone glycosides, which are toxic and can cause kidney damage and other health problems. |
| Tomatoes | Small amounts of ripe tomato flesh can be safe, the green parts of the plant are toxic due to solanine, and excessive consumption of tomatoes can be overly acidic leading to digestive issues. |
Vegetables
| Beet Greens | High phosphorus levels can inhibit calcium absorption. |
| Broccoli | Not toxic but does contain goitrogens that affect thyroid activity and can damage the liver and kidneys. |
| Cabbage | Contains goitrogens that interfere with thyroid activity. Also known to damage the liver and kidneys in tortoises. |
| Cauliflower | Similar to cabbage, cauliflower is a member of the Brassicaceae family, all of which contain goitrogens. |
| Celery | Leaves contain high levels of oxalates, and overall, the calcium/phosphorous ratio is poor. Not ideal for tortoises, although ingestion of a small amount is unlikely to cause harm. |
| Corn on the Cob | Leaves are safe but cob (or ears) contain large amounts of phosphorous, protein, and sugars which can ferment in the tortoise’s gut causing intestinal problems and possibly death. |
| Eggplant | Contains solanine, a toxin that is known to affect the nervous system and digestive system. Can be harmful in larger quantities. |
| Onions, chives and Garlic | These contain thiosulfates and other compounds that can cause oxidative damage to red blood cells, leading to anemia in tortoises. |
| Potatoes | Especially green parts and sprouts contain solanine, a toxin that affects the nervous system, digestive system, and can be fatal. |
| Spinach | Spinach binds calcium due to its high oxalate content. Although it’s not toxic, it is not a great dietary choice for tortoises, who need calcium for shell and bone health. |
Succulents and Cacti
| Aloe Vera (Aloe barbadensis miller) | popular for its medicinal properties in humans, it contains aloin, which can cause diarrhea and other digestive issues in tortoises. |
| Euphorbias (Euphorbia spp.) | This large genus includes many succulent varieties that exude a milky sap when broken. This sap contains irritants that can cause severe inflammation and burns to the mouth and digestive tract of tortoises. |
| Jade Plant (Crassula ovata) | Contains compounds that can cause nausea, lethargy, and even heart problems in tortoises. |
| Kalanchoe (Kalanchoe spp.) | Contains cardiac glycosides, particularly dangerous for tortoises, affecting heart function and causing gastrointestinal distress. |
| Pencil Cactus (Euphorbia tirucalli) | A member of the Euphorbia family, known for its pencil-like stems; its sap is highly irritating and toxic. |
| Prickly Pear Cacti (Opuntia spp.) | Many prickly pears are safe and even beneficial for tortoises, some varieties have glochids (fine, hair-like spines) that can cause physical irritation and should be handled with care or avoided. |
| Saguaro Cactus (Carnegiea gigantea) | Not typically eaten due to its hard, woody texture and large spines, but also because it is illegal to remove or damage these protected cacti in many areas. |
Supplements
Even with the best will in the world, it can be a challenge to maintain a balanced and nutritious diet for captive tortoises. Some can be fussy eaters and will characteristically pick and choose what they want to eat and then leave the rest.
Calcium can often be lacking in a tortoise’s diet, and so the use of calcium supplements without phosphorus is often necessary to achieve the right balance and prevent deficiencies or deficiency-related illnesses.
I recommend:
- Exo Terra Calcium: Phosphorus-free and is finely ground, making it easy to dust on vegetables and other foods.
- JurassiCal by JurassiPet: Made from 100% natural oyster shell, this supplement offers highly bioavailable calcium carbonate.
Vitamin D3 is another beneficial supplement that is often recommended by veterinarians.
Although tortoises synthesize Vit D3 through exposure to UVB light, they may require supplementation when housed indoors, or during the wintertime for tortoises that live outdoor.
I like Repti-Calcium by Zoo Med. This is a phosphorus-free supplement, containing D3 and without any harmful additives.
Administering Supplements
Before adding supplements to your tortoise’s diet, I recommend consulting with your veterinary first. They will be able to best advise on how much your tortoise needs and make recommendations on adjusting supplementation based on the specific needs of your tortoise, especially if there are health concerns or dietary changes.
When administering, sprinkle evenly on wet foods which will help the powder to stick. Do this for adults 2-3 times per week, but Juveniles and breeding females require more frequent supplementation.
Observe your tortoise for signs of lethargy or decreased appetite, as this can indicate over-supplementation. Adjust as necessary.
Feeding Guidelines
For captive tortoises, it’s not only important to mimic their native diet, but also to enable them to adopt similar feeding behaviours.
In the wild, tortoises can go a long time without food, and must forage for food and it’s not always in abundance, and this should be replicated for pets to avoid problems such as obesity, shell deformities, kidney and liver diseases, digestive problems, and reduced activity.
Offering variety, managing food quantity, as well as adhering to a diet appropriate for their age, and size, will help to keep your tortoise healthy and thriving. Here are some feeding schedule examples:
Juveniles: Daily feeding of leafy greens and calcium-rich foods, with small, finely chopped vegetables. Include calcium supplements 3 times a week. Place a variety of food in front of your tortoise. Allow them to eat as much as they like for 20 to 30 minutes.
Adults: Feed leafy greens and vegetables every other day, especially fibrous plants that help to encourage natural grazing behaviors. Scatter food in different areas of their enclosure to encourage movement, enrichment, and natural foraging behavior. Remove all uneaten food at the end of each day. Sprinkle calcium supplements over food twice a week.
Seniors: Continue adult diet but reduce quantities as older tortoises have a lower metabolism. Monitor weight monthly and adjust food amount accordingly. Offer softer foods if dental issues arise.
Feeding Tips
Pet tortoises are prone to becoming overweight, and obesity is a serious health concern that can lead to various complications including shell deformities, Metabolic Bone Disease (MBD), liver disease and joint and bone stress.
Just like humans, excessive weight gain in tortoises typically results from overeating, inappropriate diet, and lack of exercise.
I like to weigh my tortoises each month and get them checked by a vet every six months. That way, I can monitor their condition and adjust their feeding schedule if needed.
As a responsible keeper, it’s critical to feed your tortoise a balanced high-fiber, low-calorie diet, and adjust food quantity and feeding frequency based on the tortoise’s age, species, and activity level.
To encourage natural behaviors and ensure your tortoise gets some exercise, make sure it has enough space to roam and forage by creating substrate mounds, planting vegetation and placing rocks, slates and shelters in its enclosure.
