It is one of the largest and hardiest rhododendrons grown commercially. Barley and rye are the hardiest cereals, able to overwinter in the subarctic and Siberia. Fargesias are some of the world's hardiest bamboos, but they do not spread vigorously. This species is one of the hardiest of cherry trees, well-suited to cold climates. "Cyclamen hederifolium" is usually listed as the hardiest species of cyclamen. "C. glabra" varieties are the hardiest withstanding heavy frost and severe droughts. These palms often tolerate snow in their native habitats and are the hardiest trunking palms. Many of the hardiest species have adapted by ripening seeds over more than one summer. Windmill palm is one of the hardiest palms. Higher still, only the hardiest of plant species are found. "Iris brevicaulis" is the hardiest and most adaptable of all the Louisiana irises. It is one of the hardiest and fastest growing oaks. It is the hardiest species, tolerating temperatures down to about . Only the hardiest of plants can survive in much of this environment. It is thought to be the hardiest of all Louisiana Irises.