Foods Tortoises Should Not Eat

Twenty-eight of the 105 foods in our records carry a do not feed rating, and they apply to every species group.

Most avoid lists online treat everything on them identically, which is unhelpful. A tortoise that ate a daffodil bulb needs a vet tonight. A tortoise that ate a slice of bread needs nothing but a better diet tomorrow. This page sorts them by how much trouble you are actually in.

Tier	What it means	Examples
1. Acutely dangerous	Can cause serious harm from a single feed. Contact a vet	Avocado, rhubarb, toxic garden plants
2. Harmful with repetition	Damage accumulates over months and years	Animal protein, pulses, high-oxalate plants
3. Poor food	Not dangerous, just no reason to feed it	Bread, sweetcorn, potato

Tier 1: acutely dangerous

Food	Botanical name	Problem
Avocado	Persea americana	Hazardous to reptiles in all parts
Rhubarb	Rheum spp.	High oxalic acid plus glycosides. Leaves especially
Buttercup	Ranunculus spp.	Contains protoanemonin
Daffodil	Narcissus spp.	Toxic throughout. Tortoises have died from eating them
Foxglove	Digitalis purpurea	Cardiac glycosides
Lily of the valley	Convallaria majalis	Cardiac glycosides
Oleander	Nerium oleander	Severely toxic
Rhododendron, azalea	Rhododendron spp.	Toxic throughout
Monkshood	Aconitum spp.	Severely toxic
Ornamental bulbs	Hyacinth, crocus, tulip, iris, amaryllis	Treat the whole class as unsafe

Anything containing cardiac glycosides, meaning foxglove, oleander and lily of the valley, should be treated as an emergency.

The garden plants above are not in our food database, because nobody feeds them deliberately. They are on this page because tortoises reach them in enclosures. The Tortoise Trust is explicit that reptiles cannot reliably detect dangerous toxins in unfamiliar plants, and cites deaths from daffodils. Fence, do not trust.

Tier 2: harmful with repetition

High-protein foods

Food	Why
Dog food	High animal protein and fat, inappropriate for herbivorous species
Cat food	Same, generally worse
Meat	Animal protein has no place in a Mediterranean or grazing diet
Mealworms	Not a generic tortoise food, whatever the pet shop says
Peas and pea shoots	High protein and phytic acid
Green beans	Pods and beans both. Young leaves are a separate case
Lentils	Too protein-rich to be a staple
Kidney beans	High protein plus compounds that make them unsuitable

Excess protein in a herbivorous tortoise raises blood urea, stresses the kidneys, and is associated with bladder stones and liver disease. It also drives growth faster than the skeleton can support, producing shell deformity that cannot be reversed.

The trap is that none of it looks like a problem at the time. Tortoises eat dog food enthusiastically. Adults can carry the damage silently for years, which is why owners who have fed it “for ages with no ill effect” are usually describing an adult animal and a problem they cannot see.

Oxalate-rich plants

Food	Botanical name	Why
Spinach	Spinacia oleracea	Oxalates bind calcium into an unabsorbable form
Parsley	Petroselinum crispum	High oxalate, and a diuretic
Celery	Apium graveolens	Oxalates, sodium and a poor calcium to phosphorus ratio
Rhubarb	Rheum spp.	Also Tier 1

These are not poisons. They interfere with calcium absorption, which matters enormously in an animal already prone to metabolic bone disease.

Heavily goitrogenic brassicas

Cabbage, broccoli and cauliflower. Goitrogens can affect thyroid function when fed regularly.

Note the line is drawn by goitrogen load rather than by plant family. Kale, spring greens, pak choi, rocket, collard and turnip greens are all brassicas and all usable in rotation. Anyone telling you to avoid brassicas entirely is overcorrecting.

Other Tier 2 entries

• Onion and garlic (Allium spp.), unsuitable and potentially harmful
• Citrus, meaning orange and lemon, which disrupt gut flora
• Tomato, whose leaves and unripe fruit are toxic and whose ripe fruit is sugary filler
• Daisy (Bellis perennis), which our records mark avoid for saponin and tannin content, though other sources permit it

Tier 3: poor food rather than dangerous

Food	Why it is pointless
Bread	Processed starch, no place in tortoise digestion
Dairy	Not part of any tortoise’s natural diet
Potato	Heavy starch, and the plant contains glycoalkaloids
Sweet potato	Starchy tuber, poor mineral profile in the leaves
Sweetcorn	High starch, weak nutritional profile

Nothing here will hurt a tortoise that got hold of a bit once. There is simply no version of a good diet that includes them.

The moderation trap

Not being on this list is not the same as being good food.

Several items people assume are banned are actually rated moderation in our records, meaning limited rather than forbidden. Iceberg lettuce is the clearest example: nutritionally close to empty, but not dangerous, and it attracts far more absolute language online than it deserves. Cucumber, kale and the lettuces sit in the same band.

Equally, most vegetables and all fruit sit at sparingly for Mediterranean and grazing species without appearing here. Sparingly means occasionally and in small amounts, not freely. See the full food chart for where everything falls.

Species-specific exceptions

The 28 do not feed ratings apply to all three species groups. There is no food on this page that becomes acceptable for a different tortoise.

Two clarifications are worth making, because they get misread:

• Forest species and protein. Wild red-footed tortoises take carrion opportunistically, which is sometimes cited as licence to feed pet food. It is not. Our records still rate meat, dog food and mealworms as do not feed for tropical species, because processed pet food resembles neither the composition nor the quantity of occasional wild carrion. Their protein comes largely from young leaves, flowers and fungi. See red-footed tortoise diet.
• Mushrooms are the one genuinely species-dependent record on the site: unsuitable for Mediterranean and grazing tortoises, but part of the natural diet for forest species.

Where verdicts do change by species, it runs the other way: grasses move up for grazers, fruit moves up for forest tortoises. Nothing moves down into this list.

What to do after accidental feeding

Work out which tier you are in.

If it is a Tier 1 plant or you do not know what was eaten:

1. Remove the plant and stop any further access.
2. Keep a sample or a photograph of what was eaten. Identification matters more than anything else you can do.
3. Contact a reptile-experienced vet immediately, particularly for foxglove, oleander, lily of the valley, daffodil or avocado.
4. Do not attempt to make the tortoise vomit. It is not possible to do safely and you will only lose time.
5. Keep the animal warm and hydrated while you arrange the appointment.

If it is Tier 2 or 3, or a one-off: no emergency. Ensure water is available, return to a proper diet, and do not repeat it. A single slice of bread or one piece of cucumber is not a crisis.

When to contact a reptile vet

Beyond suspected poisoning, seek advice if you see:

• Appetite loss outside the run-up to hibernation, particularly if it persists beyond a few days
• Weight loss, or failure to gain in a growing tortoise
• Lethargy or reluctance to bask
• Soft shell, deformity or unusual growth
• Persistent loose droppings, or straining
• Discharge from eyes, nose or mouth
• Swelling anywhere, or a change in gait

The British Chelonia Group advises seeking advice within a week for a tortoise that is not eating. Reptile experience matters: a general small animal practice may not have it, and it is worth finding your nearest exotics vet before you need one.

To check any food not covered here, the tortoise food checker gives a verdict for your species group with the reasoning and sources behind it.

Ratings follow our own food records, built from the Tortoise Trust, the British Chelonia Group, The Tortoise Table plant database and published veterinary sources, and checked as described in our sources and review policy. This is husbandry information and not a substitute for veterinary care. See our veterinary disclaimer.

Last reviewed: September 12, 2026.