Rhododendrons have three great advantages: beautiful flowers, evergreen leaves and, equally important, they are resistant to frost. This places them in the group of the most attractive garden plants. During the flowering period, the shrubs attract attention with a variety of colors and forms of flowers, in the off-season they are decorated with dark green leaves.
Picturesque rose tree
The botanical name Rhododendron comes from the Greek and literally translated means: rose tree. Rhododendrons are a very old botanical genus that is represented by 1000 known wild species, mostly found in Asia.Unfortunately, most of them, due to climatic requirements, are not suitable for cultivation in Central European conditions. The first garden varieties, moreover sensitive to cold, were obtained in England at the beginning of the 19th century from the crossing of wild species imported to the British Isles. Rhododendrons grown in our gardens are woody shrubs of various sizes. In natural habitats, some species reach the size of trees, such as Rhododendron giganteum, which often grows up to 30 meters in height. Dwarf species, such as Rhododendron nivale, are found in the Arctic zone and are covered in snow for most of the year.
Large-flowered hybrids are the most abundant group of rhododendrons.While many old varieties such as 'Cunninghams White' and 'Catawbiense Grandiflorum' show strong shoot growth, reaching up to 4 meters high, modern breeding forms have a much smaller habit and a more compact crown.Variants such as 'Peggy' even after 10 years are no more than a meter high. The range of colors in large-flowered hybrids is really impressive; the latest statistics show that it is even greater than that of roses. The color palette even includes blue flowers, e.g. in the 'Blue Boy' and 'Peter Alan' varieties.
What is a threat to rhododendrons?
The most common rhododendron pest is Otiorhynchus sulcatus. This beetle damages the leaves of rhododendrons starting in May, gnawing the "sinuses" on the edges of the leaves. Swollen birds lead a nocturnal lifestyle, so during the day we will not notice them on plants. Females lay their eggs in the substrate under the plants. The protruding larvae damage the roots and the root neck of rhododendrons.
Rhododendrons for small gardens
Yakushimanum hybrids are a very good proposition for all those who do not have too much arable area in the garden.They are smaller than large-flowered hybrids, better tolerate dry sunny conditions and are tolerant to calcium. Although the selection of available varieties is not great, there is still a lot to choose from. Hybrids have flowers of various colors - from white, through pink-red and light red, to light yellow. They can also be two-tone. These colors change as the flowers develop. The inflorescences are large, composed of 16-18 flowers. In addition to flowers, their leaves also have a great decorative value - in some varieties, young leaves are covered with a delicate hair-like coating in colors ranging from silvery-white to brown-red.
Wild species are a very large group of rhododendrons, difficult to describe, with shrubs with various developmental characteristics.
What they have in common is that they have not undergone many breeding manipulations, so they have kept that timeless, recognizable, mysterious appearance for years.From them, apart from the Yakushiman genus, many large-flowered hybrids originated. They include, among others purple rhododendron Rhododendron catawbiense, whose decorative value and high frost resistance made it play a very important role in the subsequent breeding of garden varieties; rhododendron Smirnov R. Smirnowii, having more modest soil requirements and significant resistance to drought; Rhododendron maximum, blooming much later, in the second half of summer, which is rare for shrubs of this type; Caucasian rhododendron Rhododendron caucasicum likes places under the cover of pines and birches, it hates drought; Rhododendron ponticum; Rhododendron forresti var. repens; Williams' rhododendron Rhododendron williamsianum.
Azaleas are also rhododendrons, but usually with seasonal leaves.The most valuable and resistant varieties are best looked for among the Knap Hill hybrids, which are distinguished by flowers in yellow, red, orange and pink.Japanese azalea Rhododendron obtusum retains some of its leaves in winter and is an ideal shrub for small gardens. During the flowering period of May-June, the shrubs produce so many colorful flowers that the tiny leaves and shoots are almost invisible.
