Holly leaves are a good example of a plant that protects itself from the weather with shiny, thick leaves.

When it’s well below freezing, one look at a Rhododendron will remind you to put on your hat and gloves. This is called “thermoplasty,” refers to their remarkable ability to adjust growth, form, and function in response to temperature changes. This curling does several things for the plant: it conserves water, and makes less of the leaf exposed to both sun and cold. It also regulates temperatures a bit so that the foliage doesn’t warm up or freeze too quickly.    

This group of evergreens are made to conserve water in the winter. The tall white pines on the left have very skinny needles that don’t lose as much moisture through their pores as other leaves do. The Cryptomeria in the center has scale-like foliage that’s thick, and the Rhododendrons on both sides of that have thick, shiny leaves that reflect some light, repel snow, and even curl in the coldest of weather.