It is unusual to have a rhododendron collection this far north; in the 1960’s Cornell Botanic Gardens was at the northern end of the range for evergreen rhododendrons, but today many varieties are hardy to –25 or –30 degrees F. Our plants are protected here by the topography and the white pine canopy. The pines help to create acidic conditions and their high canopy helps to create the shady conditions required by these acid-loving woodland plants. During the years of establishing this garden peat moss and compost were added to improve the soil structure and help lower the soil pH. We boost the soil acidity by adding a soil acidifying soluble fertilizer each spring, and because the deer love rhododendrons, deer repellants are applied regularly. New Eastern white pines, Western white pines, and limber pines are being planted to serve as a future overstory, replacing the white pines currently being lost to age, storms and pests.
