Needing a diet with moderate protein, low fat, high fiber and water, captive desert tortoises will eat flowers such as pansies, violets, nasturtiums, hibiscus, geranium, evening primrose and globemallow.
The diet can be supplemented with vegetables like spinach, green beans, and lettuce.
Herb flowers including thyme, sage, and rosemary, all of which grow well in Tucson, can be grown around their habitat.
Greens are an important part of the tortoise's diet and provides much-needed fiber. Grass is an option for those who want a small patch of green and the leafy greens from many fresh vegetables including carrot, collard, mustard and turnip greens, provide high amounts of protein and extra water.
For more information on Desert Tortoises, check out this article by Cheryl Losch, eHow Contributor