Several years ago, one of my son’s grade school friends had a series of iguanas that lived less than a few months each. My son told me this boy fed his iguanas iceberg lettuce and mealworms. Dietary misconceptions like this cost many iguanas their lives.

Iguanas require a special–although easy to come by–diet. Our iguana, Arnold, is nine years old and nearly six feet long, so we know this diet works! Learn more about it, here:

1. High-calcium greens. Iguanas are vegetarian (one of our main reasons for getting one, rather than a reptile that eats crickets or mealworms. I decided I really didn‘t want the food chain living in my son‘s room!) But iguanas need high-calcium greens–kale, collards, arugula, watercress, or turnip greens–to stay healthy. Iceberg lettuce is not good enough! (Arnold loves turnip greens, but is less partial to collards, so we usually give him what he likes best. Experiment to see what your pet prefers.)

2. Full-spectrum light. Iguanas will not fully absorb calcium or other nutrients unless they have a full-spectrum light. (You can buy full-spectrum light bulbs at your local natural food store.)

3. Other veggies and fruits. Nitrogen-rich green beans or peas are a good addition to the iguana diet. So are yellow squashes, like butternut or acorn. Carrots and parsnips are also recommended. Fruits such as potassium- and phosphorus-laden bananas are a great treat: buy organic ones and cut in chunks with the skin still on. An occasional piece of strawberry, raspberry, or cantaloupe are also good for your pet.

4. Avoid: Beet greens and chard contain oxalic acids that are harmful to your iguana.