Rhododendron ovatum profile

Rhododendron ovatum is an evergreen shrub, 2-4 m tall; Rhododendron ovatum branchlets are grayish-brown, sparsely stipulated glands and pubescent. Leaves are leathery, ovate or elliptic ovate-ovate, dark green and shiny above, only midvein protrudes below, lateral veins and veinlets inconspicuous, glabrous. Flowers are solitary branches; axils of apical leaves; Corolla is lavender, purple or pink, radiate, 5-lobed, lobes oblong-ovate or broadly ovate. Capsule of the Rhododendron ovatum is broadly ovoid.

Rhododendron ovatum is found in thickets up to 1, 000 m above sea level. Produced in the Yangtze River and Pearl River Basin of China. The species has beautiful flowers, bright colors, and is cultivated for its high horticultural value.

Rhododendron ovatum picture

Morphological characteristics of Rhododendron ovatum

Branch

Rhododendron ovatum is an evergreen shrub (2 -- 4(-6) m tall); Branchlets are grayish-brown, sparsely stipulate glands and pubescent.

Leaf

Leaves of Rhododendron are ovatum leathery, ovate or elliptic ovate-ovate, 3.5 -- 5 cm long and 1.9 -- 2.5 cm wide, apically acute or obtuse, mucronate, base rounded, thinly broadly cuneate, dark green and glossy above, midvein and veinlets protruding, pubescent along midvein, below only midvein protruding, lateral veins and veinlets inconspicuous, glabrous; Petiole of Rhododendron ovatum is 8 mm long, narrowly winged, pubescent. Flower buds are conical, with several scales, outer scales triangular, inner scales oblong-obovate, 1 cm long and 0.8 cm wide, apex obtuse or rounded, margin revolute, with fine lashes, outer pubescent.

Flowers

Axils of apical leaves of flower solitary branches of Rhododendron ovatum; Pedicels are 0.8-1.8 cm long, densely grayish-brown pubescent and short petiolate glandular hairs; Calyx is 5-lobed, lobes ovate or longovate, 4 -- 5 mm long, 3 -- 4 mm wide, outer base densely covered with gray-brown pubescent and sparsely glandular hairs, margin glabrous; Corolla of Rhododendron ovatum is lavender, purple or pink, radiate, 5-lobed, lobes oblong-ovate or broadly ovate, 1.6-2.3 cm long, inner mask pinkish speckled, outer glabrous, tube pubescent on inner surface; Rhododendron ovatum has 5 stamens, unequal, slightly shorter than corolla, 1.5-2.1 cm long, filaments flattened, pilose below middle; Ovary is ovoid, densely covered with short glandular hairs; Style of Rhododendron ovatum is 2.4 cm long, extruding from corolla, glabrous. 

Fruit

Capsule of Rhododendron ovatum is broadly ovoid, 8 mm long and 6 mm in diameter, densely grayish-brown pubescent and sparsely glandular, surrounded by persistent calyx for enlargement.

Ecological habits of Rhododendron ovatum

Rhododendron ovatum is found at high altitudes and prefers cool and humid climates rather than hot and dry climates. A humus-rich, loose, moist and acidic soil with a pH between 5.5 and 6.5 is required. Part of the species and horticultural varieties of adaptability is stronger, drought resistance, barren, soil pH between 7-8 can also grow. But on soils with poor viscosity or permeability, they do not grow well. Rhododendron ovatum has certain requirements for light, but Rhododendron ovatum is not resistant to exposure. In summer and autumn, Rhododendron ovatum should have deciduous trees or shade shade to cover the scorching sun, and often spray the ground with water. Azalea pumping generally in the spring and autumn two seasons, mainly to spring. The optimum growth temperature is 15-20℃, flowers in summer, rhododendron resistant to pruning. Undertake pruning before May commonly, place hair is new shoot, in those days all can form bud, too late affect blossoms.

How to grow and care for Rhododendron ovatum

Water care

Rhododendron ovatum requires acidic soil for growth and development. Because the northern soil is more alkaline, so the basin soil needs to be mixed with decaying pine coniferous soil and other humus soil. The root system of rhododendron is the fine root with whisker shape, and the requirements of fertilizer concentration and water quality are strict. The principle of timely and proper amount and frequent application of thin fertilizer should be followed when applying fertilizer. In order to promote the growth of branches, leaves and buds before spring flowering, phosphate fertilizer can be applied once a month. After anthesis, apply a mixture of nitrogen and phosphorus for 1-2 times. In the growing period, flowering period fertilizer and water requirements are more, winter dormancy, summer growth is slow to control the fertilizer and water, in order to prevent root rot. Rhododendron ovatum like a wet and cool environment, the northern climate is dry, should be timely watering and spray, to maintain high air humidity. Water with alum fertilizer water and rain water as well, such as common water to add a small amount of ferrous sulfate and vinegar. Also can cut watermelon or tomato into small pieces apply, also have good effect to improving soil quality and flower quality.

The plastic clip

In order to accelerate the plant blooming, Rhododendron ovatum often through the heart to promote new branches, for flowers cluster, affect the shape of the flower can be early sparring bud, so not only make the year flowers big color fresh, but also conducive to the plant next year growth and flowering. The germination ability of rhododendron is strong, the branches seriously affect the growth and development of the Rhododendron ovatum, and reduce its ornamental and commercial properties, so it needs to be adjusted by pruning. Pruning is generally carried out in the spring after the flower has faded and autumn. Cut off dead branches, inclined branches, long branches, diseases and insects and some cross branches to avoid nutrient consumption and make the whole plant blossom and plump. 

Flowering control

Rhododendron ovatum differentiated flower buds in autumn, and the flowering time could be controlled artificially by cold storage and heating. To make the rhododendron blossom in advance, it can be moved to the greenhouse culture, control the temperature at 20-25℃, and often in the branches and leaves of water, maintain more than 80% of the relative humidity, so that after a month and a half can blossom. To make the rhododendron delayed flowering, can form the rhododendron bud, let Rhododendron ovatum have been in a low temperature state, maintain the temperature of 2-4℃, pot dry water, summer and autumn moved out of the outdoor, after 2 weeks can be flowering.

The propagation of Rhododendron ovatum

Cutting propagation

Cutting propagation is most used in the course of cultivation of Rhododendron ovatum propagation methods, generally in 5 - June shearing robust half lignification sections, 5-8 cm long, cut off the lower leaves, keep the parietal lobe 2-3 pieces as cuttings, cuttings base had better use indolebutyric acid or ABT ABT dip dip in processing such as solution, then cutting in osteoporosis breathable, acidic soil rich in humus, keep temperature in 20 to 25 ℃, shade and often spray moisturizing, so as to promote new root germination.

Twig propagation

For rare varieties that are difficult to survive, such as Western Rhododendron, first cut the tender branches about 3-4 cm as scion, cut the base into wedge shape with a sharp knife, use rhododendron as rootstock, use the tender branches for split grafting, and then put under the shade with plastic film binding, and use plastic bags to cover the scion and rootstock together to protect moisture.

Seed propagation

Because the seed setting rate of natural Rhododendron ovatum is very low, artificial pollination is generally required to improve the seed setting rate of rhododendron and obtain more seeds.Is the main approach in the azaleas in full bloom, growth better choice, design and color is beautiful, strong maternal, moved to the greenhouse, each holding select and remain large flowers, flowering early 3-4 flowers, pick to stamens and flower bud of nearby, the nutrient concentration, until the stigma head appeared mucus, which is the new brush dips in besmear of take the male parent pollen to several times. One week after pollination, the flower pot will be moved to the outside, strengthen water and fertilizer management, about 5-6 months of growth and development 

Rhododendron ovatum seeds are very small, should not be stored for a long time, otherwise the germination rate is low. If the evergreen rhododendron seeds, that is, should be planted along with the harvest, sowing in the pot in the greenhouse; If deciduous rhododendron seeds are available, they can be planted next spring.

Species taxonomy of Rhododendron ovatum

Rhododendron ovatum (original variety)

Rhododendron ovatum (Lindl.) Planch. ex Maxim. var. ovatum

In thickets up to 1000 m above sea level. Produced in Jiangsu, Anhui, Zhejiang, Jiangxi, Fujian, Taiwan, Hubei, Hunan, Guangdong, Guangxi, Sichuan and Guizhou. The type specimens were collected from Xiamen, Fujian Province.

Rhododendron ovatum (variety)

Rhododendron ovatum (Lindl.) Planch. ex Maxim. var. setuliferum M. Y. He

The difference from the original varieties is that the leaves are elliptic or oblong-elliptic, and the styles are densely bristled near the base.

Born in 350-800 meters above sea level mountain brush or sparse forest. Produced in Zhejiang, Jiangxi, Fujian, China.The type specimens were collected from Hangzhou, Zhejiang.

Rhododendron ovatum (Variant)

Rhododendron ovatum Plancha. var.lamprophyllum (Hayata) Liu,Lu

Evergreen shrubs, plant height 2-6 meters. Young branchlets covered with hairs;Leaves long elliptic to long elliptic elliptic, lateral veins 9 -- 11 pairs, midrib pilose, petiole infused, winged, fascicular branch tips.Shoot tip leaf axils germination white, pale pink to rosy flowers, with dark spots, corolla 5 lobes, obovate or obovate long elliptic, stamens 5, a single.

The distribution of Rhododendron ovatum

Rhododendron Ovatum is produced in Jiangsu, Anhui, Zhejiang, Jiangxi, Fujian, Taiwan, Hubei, Hunan, Guangdong, Guangxi, Sichuan and Guizhou provinces.

Rhododendron ovatum is found in thickets up to 1, 000 m above sea level.