A beardie really needs a balanced diet, rather than one thing constantly. You should be alternating between crickets, mealworms/superworms, and silkworms so that he gets different nutrients everyday. This should also be in rotation to greens and leafy vegetables that are not high in oxylades. Oxylades restrict calcium by binding with the molecules, making them useless to animals. The more oxylades the animal takes in, the less acutal calcium they get. Spinach, Kale, Broccoli and Parsley are high in oxylades, so feed them very sparingly (as an occasional snack, not a staple). Fruits are good, but avoid high citrus content. Carrots should also be used occasionally, since too much can result in a condition called Vitamin-A toxicidity which is lethal. Lettuce is made up of primarily water, and as such should be a snack rather than a staple. Too much lettuce causes runny stools and lets nutrients pass through faster than normal.
Dandelion greens (store bought), collards, mustard greens, bok choy, turnip greens, escarole, and chicory should be used as a primary diet. Supplement with various "snack" foods like a small lettuce leaf, a parsley sprig, chopped broccoli, or a little shredded carrot now and then will make him happy (although you might want to bury the snack food IN your salad, mine got in the habit of picking out the snack foods rather than eating what he was supposed to, smart little guy!!!). I also sprinkle in beardie pellets and other diet-specific foods like dragon yummies as a little surprise for him (and to try and coax him into eating pellets as well).
A wide variety of other vegetables can also be offered to your Beardie. Butternut squash, Yellow squash, Spaghetti squash, Acorn squash, all other varieties of squash, Green beans, Parsnips, Sweet potato, and Snow peas are all good. Squashes will either have to be cooked or micro-waved before feeding them to your Beardie. This will soften them up and they can then be minced and eaten easier.
Hope this helps.

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Dl