Azalea Japonica Dorothy

Class

Dicotyledons

Division

Angiospermae

Family

Ericaceae

Order

Ericales

Genus

Rhododendron

Species

japonicum

Description

Medium-sized acidophilous shrub with an upright, compact habit. Japanese azaleas are very common in our gardens, where they are often the most decorative and colourful part. The bushy habit, richly branched and generous in flowering gives volume to the individual plant and lends patches of colour to the entire green space.

Variety description

Azalea japonica is an early flowering species: from late April to early May, the dorothy variety is white-flowered, characterised by excellent branching and abundant flowering. Plant that requires acidophilous soil rich in organic matter. Plant that should be fertilised in a balanced way and several times a year. Plant for full sun and also for mid-shade.

Curiosities and special features

The name rhododendron comes from the Greek and literally means 'pink-flowered tree' from the terms rhodon meaning rose, and dendron meaning tree.

Origin and distribution

Native species of Japan (Honshu, Shikoku, northern Kyushu). The genus Rhododendron has ancient origins, fossil remains of the wild species R. hirsutum, indigenous to the eastern Alps, were found in both Europe and North America dating back some 50 million years. Initially considered as a separate botanical genus, azaleas were later included in the genus Rhododendron.

Flower size

The flower is medium in size, lending elegance to the lush bloom.

Leaf

The leathery leaves have an elliptical lamina.

Flowering period

It flowers from early spring to late spring for a duration of 15 to 25 days.

Leaf colour

Homogeneous colour tone, in perfect colour balance with the colour of the flowers.

Plant height

The height of the plant varies from 0.4 to 1.5 m, depending on the growing conditions. In general, it is a medium-sized shrub.

Lifespan

Polyennial shrub, usually evergreen.

Where to plant

Due to its excellent growth and flowering performance, it is the optimal choice as a plant for pots, planters, gardens and parks, flowerbeds, balconies, terraces The azalea japonica lends itself to multifunctional use, both for small to medium-sized green spaces and for larger areas, as a single specimen or in mono- or multi-coloured groups.

Stem

The stem is semi-woody with smooth bark.

Flower

The flower has a simple, medium-sized form with a star-shaped corolla and single-coloured petals. It flowers from early spring to late spring, with a flowering period of between 15 and 25 days. It is not particularly attractive to pollinating insects.

Growth

Variety with medium to vigorous growth.

Plant habit

The bushy habitus allows for visually compact and highly ornamental results.

Branching

Abundant branching gives the variety high foliage density.

PH

It is an acidophilic species that requires a soil or substrate pH between 4.5 and 6.0.

Soil preparation

Before transplanting in early spring or late autumn, carry out spading by making the planting hole of a size proportionate to the root ball and removing any weeds and bulky pebbles. Apply slow-release organic or chemical fertiliser for background fertilisation to ensure the necessary nutrients in the early stages of post-transplant development.

Sun exposure

Suitable for exposure in half shade, full sun.

Ideal climate and temperature

The ideal temperature is between 0.0 and 30 °C; it prefers mild climates.

Use

It assumes a primary role due to its colourful blooms and compact habit in:

Ornamental Outdoor Landscape Design

Hardiness

Variety of medium hardiness.

Soil

It requires acidic soil rich in organic matter. For use in pots and flowering plants, choose a specific soil for acidophilic ornamental plants, based on peat, perlite and clay granules.

Difficulty

After proper establishment in the new planting site, cultivation is easy with an overall low level of effort required. Appropriate cultivation measures with regard to substrate pH, exposure and irrigation will result in suitable growth and highly ornamental flowering.

Growing tips

Some cultivation tips for best growth and flowering results:

Balanced fertilisation Avoid over-watering Correct pruning

Combinations with other plants

For transplanting, take the seedling out of the container without damaging the roots and place it in the planting hole with the collar off the surface; also compact the soil or substrate well to avoid the formation of air pockets.

Pruning

After flowering, lightly trim branches that are too long to keep the plant compact.

Propagation

Propagation is mainly by layering or by cuttings.

Repotting

Repot in containers proportionate to the size of the plant using a specific substrate for acidophilic plants. Water after repotting.

Watering

After transplanting assist the seedling for proper establishment by watering moderately and keeping the substrate or soil moist. Then allow to dry slightly between watering, preventing both water stagnation and dryness. Use non-calcareous water with an acid pH.

Fertilising

After transplanting, apply organic or chemical granular fertiliser specifically for acidophilic ornamental plants on the surface. Afterwards fertilise in balanced doses several times a year; use a potassium-dominated fertiliser in early spring to encourage the formation of flower buds. Irrigate after fertilisation.

Edibility for humans

Species ornamental, not edible.

Tip

When growing and repotting in larger pots, prune the apical roots slightly and aerate the root ball by expanding the root system. Lightly trim branches that are too long to keep the plant homogenous or compact.