Green Iguanas


The common green iguana is an arboreal (tree living) lizard native to the tropics of Central and South America.  It is a daylight-active lizard and is almost completely herbivorous.  Well-kept animals in captivity may live 10 to 15 years and grow to be six feet in length and weigh 10 to 15 pounds.

Be very critical when choosing an iguana.  A healthy baby iguana should be alert, resting or climbing in the tree branches, and bright green in color.  It should have a slightly plump or pot-bellied appearance, and the rear legs, pelvis, and tail should be fleshy to the touch (not bony or hard).  A normal young iguana should try to elude handling, and may whip its tail or attempt to bite.  A lizard that  appears “tame” and lies at the bottom of the cage is likely ill.

Growth is rapid for a few years.  Sexual maturity normally occurs in two to three years, and full body size in three to four years.  If your iguana is not full-grown by 5 years, you can be sure that his diet or environment has been inadequate.


A 10-gallon tank is suitable only for hatchlings.  It is better to begin with a larger enclosure such as a 20 or 29-gallon high aquarium.  Be prepared to purchase or construct a larger enclosure as the animal grows.  Keep in mind that your iguana will want to climb on branches in the cage.  More complete information on building enclosures can be found in books found in your pet store, at the library, or through herpetological societies. Special effort will be required to keep up with the expanding needs of this lizard.

Cage and room light should be provided for 12 to 14 hours daily, with at least 10 hours of darkness.  A thermometer must be available to monitor temperature.  Small room thermometers that can be positioned in various portions of the cage are good.  A stick-on aquarium  thermometer at each end of the tank is also appropriate.  Cage temperatures should range 75-80 degrees at night and 85-90 degrees daytime.  A basking area where temperatures reach 100-110 degrees should also be available.  This “hot spot” can be created by shining a lamp (40 to 60 watt reflector bulb is usually adequate) onto a flat rock or large branch.  The various temperatures within the cage will allow the lizard to regulate its own temperature by moving about.  Be absolutely certain that the iguana cannot reach or touch the heat lamp.  Supplemental cage heat can be provided by heating pads or heating tape placed under the cage.  Avoid using “hot rocks;” serious burns of the underside of the iguana are a frequent finding.  Proper temperatures are important not only for activity, but also for proper digestion of food and normal function of the reptilian immune system.

Ultraviolet lighting is a necessity.  UV light on the skin converts Vitamin D to its active form.  Active Vitamin D is necessary for absorption and regulation of calcium in the body.  Poor growth, malnutrition, bone disease, and other illnesses occur quickly in the absence of Vitamin D and calcium metabolism.  UV lighting  may be provided by a Vita-lite (Durotest Corp.) available in your pet store.  Black incandescent bulbs are not adequate.  There must not be any glass or plexiglass between the bulb and the lizard as this filters out UV wavelength.  The Vita-lite bulb must be replaced after 6 months of use as it loses its UV spectrum (not visible).  The iguana should be able to climb to within 8 to 12 inches of the Vita-lite.

A bowl of water large enough for the iguana to soak in should be placed away from the basking area.  Clean the water bowl daily or more often.  Spray the iguana and cage 2 or 3 times a week with clean water, but do not keep the cage wet.

The cage floor should be covered with newspaper or Astroturf.  Keep 2 or 3 unfrayed pieces of Astroturf handy for replacement when the cage is cleaned.  Dirty pieces can be washed and disinfected, then thoroughly rinsed and dried.

Iguanas that are allowed the run of the house are not getting appropriate light and warmth.  In addition, they run the risk of falling from curtains and other high areas.  It is best to supervise your lizard’s activities when it is out of the enclosure.


Baby iguanas need more protein and so can be fed insects (crickets), mealworms, earthworms, tofu, or  hard boiled eggs as a portion of their diet (10 to 20 percent).  The greater portion of the diet should include leafy foods, mixed vegetables, and occasional fruits.  Juveniles and adult iguanas should be fed less than 10 percent animal matter. A vitamin/mineral supplement (especially Vitamin D3 and calcium) should be lightly sprinkled onto the food.

Suggested foods are listed below.  Feed babies daily and adults 4 to 5 times a week.

  • Turnip Greens, Mustard Greens, Collard Greens.
  • Dandelion flowers and greens
  • Mulberry leaves
  • Broccoli leaves
  • Spinach
  • Various squashes
  • Cactus flowers
  • Leaf (not head) lettuce
  • Mixed vegetables
  • Bok choy, kale, parsley, peppers
  • Occasional fruits including banana slices, figs, apples, grapes, tomatoes

CAUTION:  Most iguanas carry Salmonella bacteria.  They may not be appropriate pets for small children, the elderly, or individuals with compromised immune systems.  Proper personal hygiene is recommended when handling iguanas or cleaning their cages.