The resistance of various Rhododendron and Azalea species varies greatly, and, concerning conditions of Czech land, will also differ according to an area where the plant is planted. Generally, we can state that Rhododendrons do not like swift temperature fluctuations. Upon cooldown and gradual temperature drop, Rhododendron can adapt and harden so it avoids damage. It is true, though, that the general survival ability is affected by overall condition of the plant – young and well nourished plants with no fungi and pests are more resistant.
With evergreen Rhododendron cultivars, the situation is a bit more complicated – should the temperature falls below sub-zero, leaves begin to furl and leave-cell water moves to intercellular areas where it changes in the ice. The furl of leaves therefore causes a very similar process to withering. Upon warming, leaves unfurl again and retrieve their normal state. Right in this seasonal period, a shading is important, because direct sunlight causes quick melting which may sequentially cause damage to