Rhododendron (Rhododendron) includes the former two genera -Rhododendron – różanecznik i Azalea – polanka, identified by that one name. Formerly, evergreen shrubs were classified as rhododendrons, and to the clearings with leaves falling for the winter. Of the first, the purple rhododendron is most often grown (Rhododendron catawbiense), and of the others – azalia pontyjska, or yellow rhododendron (Rhododendron flavum) and Japanese azalea (Rhododendron japonicum). The purple rhododendron is a shrub with evergreen leaves, leathery, elongated (length to 12 cm) very green, lighter on the bottom. Flowers in diameter 5-6 cm, pink or other color, depending on the variety, collected in multiflorous corymbose. It blooms in May – june. Pontic azalea is a shrub that sheds leaves for the winter. They are oblong lanceolate, hairy on both sides. Yellow flowers, strongly fragrant; blooms in May before leaf development. Japanese azalea has wider leaves and flowers with wider petals, orange or salmon pink. It blooms simultaneously with Pontic Azalea.
Evergreen rhododendrons require high air humidity, hence, they grow and winter best in western and coastal areas, humus and moist soil. In winter, excess water can be harmful. They grow best in partial shade. For these plants, choose a place that is sheltered from winds, and in areas with more severe climates, rhododendrons should be protected with coniferous branches for the winter. It is also recommended to mulch the ground around the bushes with straw or leaves, to protect the root system against an excessive temperature drop. Leaf-shedding species are less sensitive, but they have similar requirements. The condition for success in their cultivation is acidic soil.