The Basics:

Most Green Iguanas available to the pet trade today are captive bred animals, either raised in Mexican farms or by domestic breeders. Green Iguanas have an excellent sense of vision, hearing and smell. Males grow to 6-feet or more, and females are noticeably smaller. Adult size is typically reached between 24 and 36 months. The Green Iguana's long tail serves as a defensive weapon when it is snapped in the air. Diurnal animals, Green Iguanas are most active during the day. Young Green Iguanas are bright green in color, but they become lighter over time. Healthy young iguanas are feisty animals that tend to run around madly and often slash their tails when anyone attempts pick them up. (A baby that sits still and lies calmly is not tame, it's probably sick.). During breeding season, some males will develop orange coloration over parts of their bodies. Males will also become more territorial and aggressive during these periods. In nature, Green Iguanas are largely solitary animals. Males will often fight fiercely if housed together.

Enclosure:
These Big Lizards Need Space:

The Green Iguana's sheer size demands that it be provided with a spacious enclosure. Hatchlings under six months of age can be kept in a 40-gallon or larger aquarium tank with a screened top. However, by the time a Green Iguana reaches a half-year, it must be provided with larger living quarters. An adult iguana needs an enclosure that measures at least 8-feet high, by 8-feet long, by 6-feet wide. The larger the enclosure, the better it is for the Green Iguana. Small housing not only causes stress, it limits an iguana's exercise, weakening its muscles. Most likely, a custom enclosure will have to be made for the adult iguana. Height is especially important in a Green Iguana's enclosure, since these lizards will experience severe stress if they do not have the opportunity to climb. Any enclosure must include climbing shelves or branches that are a little wider than the diameter of the Green Iguana and
sturdy enough to support its weight. Wide shelves made of various sized boards are recommended over branches, because they are better able to support an iguana
comfortably and safely.

Substrate:
Avoid Materials That Can Be Ingested:

Green Iguanas do well with substrates such as newspaper with non-toxic ink, plain butcher paper, paper towels and
indoor/outdoor carpet. Particulate substrates such as sand and wood chips should be avoided, since this material can stick to an inquisitive iguana's tongue (they like to
explore their environment by flicking their tongues) then be ingested and cause blockages. Aromatic wood shavings such as cedar should never be used, since their fumes promote respiratory problems

Outdoor Sunlight Exposure:

The best source of UVB light for an iguana is the sun. In
some climates and during some seasons, Green Iguana keepers can expose their pets to natural sunlight. The UVB from natural sunlight is filtered out by most window glass and
significantly reduced by obstructions like screen or mesh, so the iguana should be housed in an outdoor basking cage. A Green Iguana should not be placed outdoors if the temperatures are below 80 degrees or above 100 degrees Fahrenheit. It's essential that a thermal gradient be provided in the outdoor cage, so the iguana can regulate its body
temperature. Half the cage should be in the sun, and half in the shade. Clean, fresh chlorine-free water should always be available in the outdoor cage, since Green Iguanas can become
dehydrated. An iguana should never be outside without direct supervision from its keeper. Just one hour in the sunlight will provide an iguana with a sufficient daily supply of UVB light.

Temperature:
Adequate Heat Critically Important:

Green Iguanas are tropical animals, and it is essential that they be provided with sufficient heat. An enclosure that is too cool will make it difficult for Green Iguanas to digest food, and create a variety of other medical issues. Ambient daytime temperatures in the tank should be in the 80-85º Fahrenheit range, with a warmer basking area in the 90-95º range. At night the temperature should be dropped to the mid 70's. Heat lamps can be used to maintain the desired thermal gradient, while a lamp can heat the basking spot. (Never use hot rocks, since they can burn the animal’s skin.) Under tank heaters are not recommended, since they can draw the Green Iguana away from the overhead UVB light. Nighttime temperatures can be maintained by using ceramic heat emitters, which do not produce light. Follow directions carefully with ceramic heat emitters, use fixtures with porcelain or ceramic sockets and to protect against fires, do not place them by dry wood or flammable fabrics. Thermometers should be positioned in the warmer and cooler areas of the enclosure as well as in the basking spot. Enclosure temperatures should be monitored at branch level as well as ground level.  Important - see the Note About Day/Night Light Cycles and Heating below.

Note About Day/Night Light Cycles and Heating:

All reptiles, including this pet, must have distinct day and night periods in their enclosure to maintain their biological rhythms. (See the lighting entry above for the specific length of this animal’s day/night cycle.) The day period must be light; and night must be dark. A timer should be used to set day/night periods. If a heat source is required to maintain correct nighttime temperatures, use heat mats or strips mounted below or on the side of the tank, infrared heat lamps, ceramic heat emitters, or a combination of these products. This will allow the enclosure to be heated while remaining dark. Follow directions carefully with all products. If ceramic heat emitters are used always choose fixtures with porcelain or ceramic sockets and to protect against fires do not place them by dry wood or flammable fabrics. Ceramic heat emitters must be kept out of the reach of children and all pets, including dogs and cats.

Diet:
All Vegetables:

Although at one time it was widely believed that iguanas benefited from being fed meat proteins, this was proven to be totally false. Green Iguanas are herbivores, which means they eat plant matter and only plant matter. Animal meat, eggs
and dairy products should never be fed to a Green Iguana. Dark leafy calcium-rich greens should make up over 60-percent of the iguana's diet. These include mustard greens, watercress, collard greens, endive, and dandelions. Romaine and green leaf lettuce should also be offered. Spinach should be avoided, since it contains an ingredient that binds calcium. About 20-30 percent of the iguana's diet should consist of grated carrots, squash and cucumber. Broccoli, brussels sprouts, cabbage, kale, escarole, and cauliflower should be avoided because they contain an iodine binder that can contribute to thyroid problems. The remainder of the diet should consist of fruits such as strawberries, mangos, papaya, kiwi, melon and apple. Grain based food such as rice and pasta can be given as an occasional treat.

Iguanas should be fed daily, and given as much food as they want, following common sense guidelines. All food should be fresh, and washed before being offered to an iguana. Food should be cut or chopped in a size that's appropriate for the size of the animal. Any food that an iguana doesn't eat during a sitting should be removed before it spoils. Clean fresh chlorine-free water should always be available. Since Green Iguanas will often defecate in water, this water bowl should not be large enough for an iguana to wade in. It's a good idea to spray chlorine-free water on an iguana's vegetables before they're offered, since many of these lizards prefer to "drink" this way. 

Iguanas have complex nutritional needs.  A varied diet is important to their health.  Owners should learn all they can about the nutritional needs of their pets.

Important -- It is necessary to provide calcium and vitamin supplements as part of the diet. Please read the supplement section below: