Rhododendron indicum
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Rhododendron indicum is a beautiful showy plant that requires lots of maintenance. This plant can be difficult to grow and has lots of pest issues, although it is tolerant to rabbits. Definitely not recommended for beginners, but to those who have some experience and time to provide the proper care for the plant it can be an attractive addition to the shady area of one's garden.
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Family |
Ericaceae |
Genus |
Rhododendron |
Species |
indicum |
Category |
Woody |
Type |
Shrub (evergreen) |
USDA Hardiness Zone |
7 - 8 |
Canadian Hardiness Zone |
6b - 8a |
RHS Hardiness Zone |
H4 - H6 |
Temperature (°C) |
(-20) - 20 |
Temperature (°F) |
0 - 20 |
Height |
0.6 - 0.9 m |
Spread |
0.6 - 0.9 m |
General Description |
Rhododendron indicum is a small, poisonous, slow growing, and dense woody broadleaf evergreen shrub. This plant belongs to the Ericaceae family, and its common name is the Southern Indian Azalea. Rhododendron indicum flowers in the late spring but sometimes will flower a second time in autumn. |
Landscape |
Rhododendron indicum is used for many different purposes in the landscape such as specimen planting. The flowers on the plant attract bees and other pollinators to gardens. Rhododendron indicum is typically used in mass planting and as a hedge. This plant is also good for shade gardens as it prefers shaded areas rather than sunny ones. |
Cultivation |
Rhododendron indicum prefers moist acidic soil. This plant will not tolerate drought and needs to always have moist, well drained soil. This plant also needs partial shade and not full sun. The pH of the soil should lay between 4.5 and 5.5. Rhododendron indicum likes a more sandy or silty soil. Not wind tolerant and should be planted in a protected area. This plant can also be used for bonsai. |
Shape |
The shape of Rhododendron indicum is upright and wide spreading. Proper pruning after flowering will create an even denser shrub. |
Growth |
Slow |
ID Characteristic |
The best three ID characteristics to look for when identifying Rhododendron indicum are both leaves and stems; they have small hairs making them almost fuzzy, are a dark green colour on the top of the leaves and a lighter green under the leaves, with large pink/red 4 to 5 petal flowers. |
Pests |
Rhododendron indicum has many pest problems and is quite susceptible to diseases. Common pests that affect this plant include aphids, scale, borers, mites, and thrips. Some common diseases that may affect the plant are canker, leaf spot and powdery mildew. Rhododendron indicum gets root rot fairly easily and is something to constantly watch for as it can be detrimental to the plant. Proper care and maintenance of the plant will help to prevent most of these issues. |
Habitat |
Rhododendron indicum can be found naturally in rocky ravines and in rocks along rivers in Japan. |
Bark/Stem Description |
Young stems are smooth and have a reddish-brown colour to them; also covered in small brown hairs. The bark on the plant has a flaky texture. |
Flower/Leaf Bud Description |
Flower buds are found at the end of stems and are scaled. The flower buds are small around 1-3cm in size, and are egg shaped. Buds for flowers and leaves are a light green colour. |
Leaf Description |
Leaves on a Rhododendron indicum are in an alternate arrangement and have a lanceolate shape. Leaves are also slightly toothed with a crenate leaf margin. Leaves have a bright dark green top and a lighter green underside in warmer months and turn red in winter. Petiole and veins on leaves are covered in fine small hairs. |
Flower Description |
The flowers on Rhododendron indicum are a showy bright pink or red colour. Flowers bloom in late spring and sometimes a second time in mid autumn. These flowers attract many pollinators like bees. These flowers are singular, and it is extremely rare for them to have double. Each flower has 4-5 lobes that are long and create a funnel shaped flower. Flowers are roughly 2cm-5cm in size. |
Fruit Description |
The fruit on a Rhododendron indicum is 5 valved capsules. The fruit are also hairy. The size of the fruit is roughly 5cm long. |
Colour Description |
Colour of the foliage of Rhododendron indicum is a dark green on top of leaves and a lighter green on the under sides through out spring, summer and autumn. During the winter the foliage turns a deep red colour. Bark colour of this plant is a dark reddish brown. The flowers on this plant are most commonly pink or red but they can also be white or lilac. |
Texture Description |
Rhododendron indicum is a very fine textured plant in both summer and winter months. |
Propagation |
Rhododendron indicum can be propagated by cuttings, seed, and grafting. Cuttings of stem tips should be taken during the summer and soil should be moist and warm (70-75 degrees F). Rooting takes about 8-12 weeks. When seed propagating, seed should be taken in autumn and sowed in late autumn. Germination takes 2-4 weeks. Seeds should be potted and grown in a greenhouse for the first winter. When propagating by grafting all suckers should be removed so they don’t take over. |
Ethnobotanical Uses (Disclaimer) |
Rhododendron indicum is a poisonous plant so it is not used for any edible purposes. This plant has no known medical uses past and present. An extract is taken from the flower and used in some hair conditioners. |