The rhododendron is a popular flowering shrub. It is an evergreen plant, and therefore does not lose its leaves in winter. It is particularly sensitive to dry spells and low moisture, so proper winter care can be especially important.
Water and Fertilization
Because the rhododendron is a cultivated species, it is less capable of regulating its seasonal processes. The Oregon State University Extension explains that dormancy in particular can pose problems for the rhododendron, and gardeners will need to help the process along by limiting nitrogen intake before the cold weather hits. B.F. Lancaster, writing for the Journal of the American Rhododendron Society, explains that fertilization “at a later date is very apt to promote too much late growth that may not be hardened in enough to survive an occasional early frost.” Many growers, he says, recommend tapering off or withholding water to harden wood for winter, but Lancaster advises against starving rhododendrons of water entirely, since winter is a dry season and the plants will need stored water to survive it.
Cold winter winds can prove quite damaging to the rhododendron. The National Gardening Association recommends that growers in regions with severe winters protect their rhododendrons by wrapping them in burlap. In addition to burlap, Demesne.info suggests planting your rhododendron in proximity to a natural windbreak in the form of taller evergreen shrubs. Exposed leaves can suffer from leaf burn when whipped by frigid winter winds, and burlap wrapping or providing a natural wind screen can help prevent damage.