Rhododendron

A broadleaf evergreen shrub reaching 3 to 4 ft tall and 2 to 5 ft wide. Hardy in Zone 6a to 9b. Native to southern Europe and southwestern Asia, where it grows in forests under Fagus, Picea, and Abies species. R. ponticum is one of the most widely used rootstocks for grafted rhododendron cultivars and a significant parent in many elepidote hybrids.

Part shade on moist, acidic soil (pH 4.5 to 6.0). Slow growth rate. While valued as rootstock and breeding stock, R. ponticum has become seriously invasive in parts of the British Isles and should be monitored in favorable climates. Twenty-four diseases and 15 pests documented at the genus level. All parts are toxic if ingested.