Rhododendron: One of the most beautiful winter-flowering ornamentals
Rhododendron: Shrub or tree with particularly impressive flowers and ideal for intense color in gardens and balconies at a time when few ornamentals are in bloom.
Perennial and evergreen or deciduous shrub/tree, depending on variety. Closely related to the Azalea, the Rhododendron genus also belongs to the Ericaceae family and includes more than 1,000 different species, most of which originate from East Asia and mainly the Himalayas, which is why it is the national flower of Nepal.
Most varieties are considered edible and in areas of the Himalayas their flowers and nectar are used apart from traditional medicine in cooking or for the preparation of teas. Nevertheless, a few of the rarest Rhododendron species are highly toxic to humans, but mainly to equines, and cases of horse death have been recorded just a few hours after ingesting the plant.
The bushy varieties have a height of 40cm to 2 meters, while tree-like adult plants of certain varieties can even exceed 10 meters and take the form of a tall tree with particularly dense foliage, which during its flowering period is truly … magical view. The most common varieties have flowers in pink-purple or red shades, which are quite similar to those of Azalea but are much larger in size, while there are also Rhododendrons with yellow, white or even two-color flowers. Suitable for individual or mass plantings in gardens – flowerbeds, it also grows equally well in containers where it can thrive for several years as it is a generally slow growing plant.
Soil: The quality of the soil is the only special care that the Rhododendron needs, just like all acidophilic plants (Gardenia, Azalea, etc.) It does not like calcareous soils at all and needs acidic soil (pH between 4.50 – 5.50), while for potted plants the special potting soil for acidophiles should be used. Its soil should have very good drainage and at the same time keep a minimum of moisture between waterings. Covering the soil around the roots with tree bark, straw, etc. is one way to retain moisture.
Position: It thrives in semi-shady and shady places, with ideal positions receiving a few hours a day of indirect morning or afternoon sun, while under no circumstances should it be exposed directly to solar radiation, especially at noon. It also grows excellently in the shade – semi-shade of coniferous trees, a point where many ornamentals do not thrive. A plant with enough resistance to low temperatures, as long as it is protected from strong wind. When conditions of prolonged cold – frost prevail, especially the bushy varieties and small plants in pots, it is good to protect them with an anti-freeze cover.
Watering: It needs frequent watering, 3-4 times a week in the hot periods of summer and certainly much less in the rest of the seasons. In spring and autumn, if the rainfall is not sufficient, it should also not be neglected to water it 2-3 times a week, as long as its soil has very good drainage.
Pruning: After the end of flowering it can be pruned – lightly pruned, to maintain its shape and to remove any dry and weak branches. It is generally a slow-growing plant and is therefore not suitable for “deep” pruning. Removing the withered flowers contributes to even more intense flowering.
Fertilization: From the end of flowering until the following May – June, a special booster for acidophiles once a month, significantly helps the general health of the plant and its faster growth. The last fertilizing should be carried out at the beginning of summer, even if the temperatures are not particularly high, conditions that are anyway prohibitive for fertilizing all plants. The reason is that in the next period it does not develop many new shoots and most of the existing ones have time to become woody so that they are not particularly sensitive during the winter.
The Rhododendron blooms in December and its flowers last until February. Its propagation is not always successful and is done by tender cuttings immediately after the end of summer.
The rooting hormone helps significantly in the success of the project, as very often new plants grow very slowly and need to pass 3-4 years before their first flowering.
In large nurseries you will find bushy and low tree varieties of Rhododendron plants to add this very beautiful plant to your garden or balcony, especially during the winter when few ornamentals are in bloom.