According to Sulcata Station, a sulcata tortoise eats dry grasses and weeds because its natural habitat is semi-arid. It requires a diet that's high in fiber and calcium and low in protein.
The primary foods for the sulcata tortoise are grasses, edible weeds, leaves and flowers and occasionally dark leafy greens. An owner needs to feed his tortoise different types of grass at least 75 percent of the time because a tortoise needs a diverse diet. Buffalo grass, bermuda grass, orchardgrass, Western wheatgrass, Arizona fescue and creeping red fescue are just a few varieties that tortoises enjoy. The remaining 25 percent of the time, a tortoise needs weeds, leaves and flowers, such as dandelions, hollyhock, rose blossoms, hibiscus, geraniums and grape leaves. Occasionally a tortoise can have some dark leafy greens like spinach or kale, but only once in a while and only in small quantities because these greens have a high protein content. Tortoises do not hibernate during the winter, but they can live off of grass hay during those colder months.
Sulcata tortoises should not be fed grains or grain products, legumes, pet food, dairy products, fruit or vegetables. Feeding tortoises the wrong foods or too much food can cause developmental problems, like growth spurts that result in the development of abnormal shells.