Most of the issues with plants dying inside of chameleon enlcosures come down to two main factors, light and moisture. While it seems like a UVB light would be best for growing, it really isn't. At least not from a flouro or two. The amount of penetration isn't deep enough for a large plant to sustain itself. Mercury Vapor bulbs help this immensely, but may be too much for your cham depending on your setup. Also, flowering plants like hibiscus cannot fully cycle through the vegatative and flowering stages with only a cool spectrum of light. A good practice is to have a spare set of plants for your chams enclosure, and cycle them out every other month to let them recouperate with some sun.
The other major factor is over-saturation. While plants use Co2, the roots still also need oxygen as well. Soil that doesn't dry between watering cannot aerate and will choke the roots, inhibiting growth and eventually causing rot. Since we can't simply stop misting our chameleons for a few days, you have to increase the drainage of your plants. First, I remove the collection tray at the bottom of a pot. Then I pull up the plant and fill the bottom 2-3" with gravel. I then wash all the soil off the root ball and replant with a mixture that is high in perlite but low in vermiculite. Make sure to top it off with a screen or river stones so your chameleon doesn't eat the perlite.
Fertilizing is essential as well, but in moderation and organics only for the chameleons.
