Tortoises are "grazers", - they do best when allowed to chomp naturally on wild growing weeds and flowers, and should only be offered extra food items sparingly ( I feed mine three times a week)
They should be allowed controlled inactivity periods , and discouraged from a 365 day feeding program.
Never offer any foods which contain high amounts of protein (peas & beans in particular) or have an extremely negative calcium to phospherous balance.
Rarely, if ever, offer any fruit as this can lead to flagellate proliferation and colic
Always ensure an adequate water supply is available.
Regularly supplement food items with a good calcium and vitamin powder, and "D3" if housed indoors for long periods of time.
Vary the diet as much as possible.
The following list of wild plants, cultivated plants and salad items can be used to form the basis of a good balanced diet, in addition to natural grazing, for all Mediterranean species. Plants with a " # " marked alongside (too much oxalic / phytic acid, poor fibre content, or slightly high protein content) should only be offered occasionally, however they're perfectly fine in very moderate proportions, as part of an overall mixed and balanced diet. It is worth noting that when collecting wild foods, try to stay clear of any areas which may have been sprayed with pesticides or suffered heavy pollution from traffic fumes etc, as tortoises are intolerable of these.
Basic recommended food items
Dandelion , Trefoils , Honeysuckle , Cat's ears , Vetches , Sowthistle ,
Hawkbits , Hawkweeds , Plantains , Clover (red and white) , Pansies ,
Rose leaves and petals , Hibiscus , Mallows , Grape vine leaves , Agave plant , Mulberry leaves , Bindweeds , Opuntia cacti pads and fruit , Romain or red leaf lettuce , Watercress , Endive , Escarole , Chicory , #Cabbage , #Beet greens , #Kale , #Alfala hays , #Finely choppped carrot.
Most tortoises instinctively seem to know what foods may be poisonous to them and generally tend to leave them alone. Also, due to their incredibly slow digestive system, tortoises are sometimes able to de-toxify certain poisonous plants. the following list (compiled by the Tortoise trust) are plants which could cause harm. The ones marked with a "#" have been known to cause death, so should be completely avoided.
Poison plant list
#Any ornamental bulbs , Acokanthera , Aconite (monks hood) , Amaryllis , Amsinckia (tarwwed) , Anemone , Avocado (leaves) , Azalea , #Baneberry , Beach pea , #Betal nut palm , #Bellaonna , Bittersweet , Bird of paradise , Black locust , Bleeding heat , Bloodroot , Bluebonnet , Bottlebrush , #Boxwood
Buckeye horse chestnut , Buttercup , Caladium , Call lily , Cardinal Flower , Carolina jessamine , Casava , Castor bean , Chalice or trumpet vine , cherry - (seeds only) , Cherry laurel , China berry tree , Christmas berry , Columbine ,
Christmas cactus (Euphorbia) , Christmas rose , Common privet , #Crocus ,
Coral plant , Croton , Cyclamen , #Daffodil , Daphne , #Death camus ,
#Deadly nightshade , Delphinium , #Destroying angel (death cap) , Dogwwod ,
Elderberry , Elephant ear (taro) , English Ivy , False Hellebore , Fiddle neck ,
#Fly agaric (amanita,deathcap) , Four o'clock , #Foxglove , Gelsemium , Golden - chain , #Hemlock , #Henbane , Holly , Horse chestnut , Horsetail reed ,
Hyacinth , #Hydrangea , Impatiens , Iris , Ivy , Jack-in-the-puplit , Jasmine ,
Jatropha , Jerusalemcherry , Jessamine , #Jimson weed (thorn apple) , Johhnson- grass,wilted , #Lambkill (sheep laurel) , Lantana camara , Larkspur , Laurel ,
#Lily of the valley , Lobelia , #Locoweed , Locust , #Lupin , Machineel , May apple , #Mescal , Milk Weed , #Misletoe , Moccasin flower , #Monkshood , Moonseed , Morning glory , Mountain laurel , Narcissus , Natal cherry , Nectarine (seed only) , #Nicotine tree/bush -flowering , nightshades , Oak , Oleander , Pear seeds , Pennyroyal , Peony , Periwinkle , Philodendrons , Pinks , Plum seeds , Poinsettia , #Poison hemlock , #Poison ivy , #Poison oak ,
#poison sumac , Pokewood or Pokeberry , poppy , #Potato (leaves) , Privet , Redwood , #Rhubarb (leaves) , #Rhododendron , Rosemary , Russian thistle ,
Sage , Salmonberry , Scarlet pimpernel , Scotch broom , Senecio , Skunk cabbage , Snapdragon , Spanish bayonet , Sqirrel corn , Sudan grass , Star of Bethlehem , Sundew , Sweetpea , Tansy , Tarweed , Tiger Lily , Toad flax ,
Tomato (leaves and plant) , Toyon berry , Tree of Heaven , Trillium , Trumpet vine , Venus flytrap , Verbena , Virginia creeper , #Water hemlock , Wild parsnip , Wisteria , Yellow star thistle , #Yew.
you can also find all sorts of seeds for the above non poisonouse plants avaliable on e-bay and from tortoise specialists that you can grow yourself in a specific garden plot or in seed trays for your tortoise to feed on.I would stay well clear of any dried pellet type food.You are also right not to feed him green lettuce .
Just read abbey e's reply and if she doesn't change his diet asap she will have a very ill if not dying tortoise on her hands in the near future.