Mediterranean Tortoise Diet: Feeding Testudo Species in Britain

Mediterranean tortoises need a diet built on weeds, leaves and flowers: high in fibre, high in calcium, low in protein, low in sugar and low in digestibility.

That last word is the one almost nobody mentions, and it turns out to matter enormously. A captive tortoise can be fed nothing but safe plants and still be fed wrongly, because the fibre in a bowl of fresh salad behaves nothing like the fibre in dry Mediterranean scrub.

Which species this covers

Four Testudo species make up almost every pet tortoise sold in Britain.

Testudo hermanni, Hermann’s tortoise. Testudo horsfieldii, sold as the Horsfield’s or Russian tortoise. Testudo graeca, the spur-thighed or Greek tortoise. Testudo marginata, the marginated tortoise, the largest European species.

They share a feeding template. They are not identical, and the section at the end of this page sets out where the differences actually bite.

Natural feeding ecology

Field studies of wild Testudo give a picture quite different from the one most captive diets are built on.

They eat a lot of different plants. Andreu recorded 88 plant species eaten by Testudo graeca graeca in Doñana in southern Spain. A study in an overgrazed area of the Moroccan Atlas found 34 species taken during spring, with five accounting for around 70% of intake: hawkbit, small-flowered mallow, and three legumes.

They do not eat fresh green material by preference. This is the finding that overturns most captive practice. Even where fresh vegetation is available, wild tortoises take a mixture of fresh and older, drier material. Seeds form a significant part of the intake, and in dry periods faecal pellets can be dominated by them.

They do not feed continuously. Activity is seasonal and daily. Spanish T. g. graeca emerge around mid-March, feed hard through an April to June flush, then aestivate through a summer when ground temperatures can exceed 60 degrees and almost no green vegetation survives. Autumn rains bring a second flush and a second feeding season before a short winter brumation.

Their habitat supplies calcium. The landscapes of Murcia and Almeria are rich in calcium carbonate, which shows up in the mineral content of the plants growing there. Wild tortoises also eat discarded snail shells, which turn up regularly in faecal analysis.

Why fibre length matters more than plant choice

The Tortoise Trust’s fieldwork on dietary fibre in wild Testudo graeca graeca makes a point that changes how you should feed at home.

Tortoises ferment their food using gut microbes, and the speed of that fermentation depends heavily on particle size. Fine particles and short fibres, under about 3mm, are digested rapidly, release energy quickly and drive fast growth. Coarse particles and long fibres, over about 10mm, break down slowly and release energy gradually.

Wild tortoises swallow leaves and flowers whole, without chewing. The only surfaces exposed to gut microbes are the severed ends, because the waxy cuticle protects the rest. Chop that same leaf finely and you have created far more surface area and a much faster energy release from identical ingredients.

The gap between wild and captive is large. The Trust estimates the gross fibre content of an average captive diet may be up to 80% below what a wild tortoise consumes. Research by Hatt and Clauss suggests crude fibre needs to be in the region of 30 to 40% on a dry matter basis to keep digestibility down. Most commercial pelleted foods declare substantially less than 20%, and some below 12%.

Three practical conclusions follow.

Do not chop food finely. Offer whole leaves and flowers where you can.

Include coarse dried material, not just fresh green. Dried herbs, flowers, seed heads and stalks are closer to the wild intake than a bowl of fresh salad, and they are the part almost every captive diet is missing. See dried tortoise food.

Treat supermarket salad as the weakest option available. It is low in fibre, high in readily digestible starch and sugar, poor in calcium and extremely high in water, and keepers and vets both report loose droppings on it.

Suitable UK foods

British weeds do a decent job of approximating Mediterranean scrub, which is fortunate.

Regular: plantain, sow thistle, mallow, hawkbit, bristly oxtongue, nipplewort, hibiscus, viola and pansy, violet, calendula, campanula, corn salad, mint, thyme. Every one of these grows here.

Hawkbit and mallow are worth pointing out, since both appear in the list of five species making up 70% of wild spring intake in Morocco. They are not exotic. They are common British weeds.

Rotate: dandelion, clover, chickweed, nettle, bramble, kale, spring greens, watercress, rocket, chicory, endive, pak choi, rose, cornflower, nasturtium.

Sparingly: carrot, courgette, cucumber, bell pepper, and any fruit.

The best weeds for tortoises covers identification, and growing your own is worth doing if you have any outdoor space at all. To check a specific item, the food checker gives verdicts for this group.

Foods to avoid

Animal protein in every form, including dog food, cat food, meat, mealworms and boiled egg. Peas, beans and pulses. Bread and processed human food. Tomato, spinach, rhubarb, celery and parsley for their oxalate content. Cabbage, broccoli and cauliflower as the heavier goitrogenic brassicas. Potato and sweetcorn for starch. Onion, garlic and avocado outright.

Fruit belongs here too for practical purposes, kept to occasional small amounts at most. Sugars and starches accelerate fermentation in a gut that is meant to work slowly, which is exactly the wrong direction for these species.

The full list is at tortoise foods to avoid.

It is worth remembering how recent good advice is. Thirty or so years ago, organisations and vets in Britain were still recommending lettuce, tomato, dog food and boiled eggs, and UVB was barely mentioned. Anyone repeating advice they were given decades ago is repeating that era.

Seasonality

Wild Testudo have two feeding seasons and two rest periods. Most captive tortoises in Britain get one long, uninterrupted feeding season instead, which is a substantial part of why overgrowth and obesity are so common.

Spring is the natural peak. Fresh weeds, growing fast, taken heavily. A planted outdoor pen does this better than a bowl.

Summer in the wild means aestivation and near-total inactivity. In Britain the weather does not force that, so the temptation is to keep feeding at spring levels. Resist it. Let the graze in an outdoor pen coarsen naturally as the season goes on rather than compensating.

Autumn brings a second flush in the wild. In Britain, feeding tapers off before hibernation so the gut can empty, as feeding before hibernation explains.

Winter is the hard part. British forage disappears and most keepers switch to bagged greens, which is precisely when the fibre problem gets worse. Dried forage matters most in these months. See winter feeding.

Supplements and calcium

Calcium and vitamin D3 sit at the centre of every serious health problem in this group.

Wild Testudo get calcium from mineral-rich plants, from calcareous substrate and from snail shells, and they synthesise all their D3 from strong Mediterranean sunlight. A British garden supplies far less of both. UVB does not pass through glass, so a windowsill contributes nothing at all.

Rapid growth makes this worse rather than better, because fast-growing bone places heavier demands on calcium and D3 metabolism. A tortoise growing quickly on a low-fibre, highly digestible diet is the classic metabolic bone disease case. See calcium and supplements.

On commercial food, the Tortoise Trust’s objection to mass-market pellets is specific rather than general: fine particles, short fibres, low declared fibre content, and grain or maize-based ingredients that raise digestibility further. The Trust does regard some products more favourably, naming the Pre-Alpin and Pro-Alpin Testudo range for including a broader spread of plant species and omitting grain derivatives. We have not tested these ourselves and are reporting the Trust’s position. Both sides of the pellet argument are in our guide to tortoise pellets.

Where species-specific guidance differs

The four species share a template but not a lifestyle.

Horsfield’s is the outlier. It is a true desert and steppe animal, active for as little as three months a year, and it aestivates as well as brumates. It tolerates cold well and damp badly, and overfeeding harms it faster than any other species in this group. See Horsfield’s tortoise diet.

Hermann’s favours legumes and clovers over grasses, and field studies show a seasonal shift towards flowers and unripe wild fruit in autumn. It handles British conditions comparatively well. See Hermann’s tortoise diet.

Spur-thighed tortoises span an enormous range from Morocco to the Middle East, with correspondingly variable subspecies. Southern lowland populations aestivate through summer. See spur-thighed tortoise diet.

Marginated tortoises come mainly from Greece and grow larger than the others, which affects quantity more than composition. See marginated tortoise diet.

For the nutritional reasoning behind all four, read tortoise diet. For the other habitat groups, see tortoise diets by species.

Guidance here draws on the Tortoise Trust, the British Chelonia Group, published field research and veterinary sources, checked as set out in our sources and review policy. It is husbandry information rather than clinical advice, and our veterinary disclaimer explains the difference.

Last reviewed: September 2026.