How to Grow Rhododendron pulchrum? A Detailed Guide to the Latest Cultivation Methods
Rhododendron pulchrum, also known as Splendid Rhododendron, is an evergreen or semi-evergreen shrub of the genus Rhododendron in the family Ericaceae. When planted in masses, it blooms in a splendid Brocade-like display of a myriad of colors, which can enhance the natural landscape effect of gardens. It can also be planted in clumps beside rocks, by pond edges, and along lawn borders to add to the garden atmosphere. Placed as a potted plant in hotels, homes, and public places, it is dazzling to the eye. Now let us take a look at the cultivation methods for Rhododendron pulchrum!
Growth Habits of Rhododendron pulchrum
Rhododendron pulchrum is commonly cultivated throughout China, and wild Rhododendron pulchrum is found in the Jiuling Mountain area of northwestern Jiangxi Province. It prefers a cool, moist, and sunny environment. It is cold-tolerant, heat-sensitive, tolerant of partial shade, and not tolerant of prolonged intense sunlight. The optimum growth temperature is 15-28°C, and in winter it can withstand low temperatures of -8°C. The soil is best as fertile, loose, well-drained acidic sandy loam.
Propagation Methods of Rhododendron pulchrum
1. Cuttings: Propagation of Rhododendron pulchrum by cuttings is carried out during the plum rain season. Select semi-mature young shoots 12-15 cm long, remove 2-3 leaves from the base, keep the apical leaves and cut them in half. Treat the cuttings with 0.8% indolebutyric acid solution for 2-3 seconds, insert them into a sand bed, and keep the room temperature at 15-18°C. Roots form 50-60 days after insertion.
2. Layering: Propagation of Rhododendron pulchrum by layering is carried out in April-May using the air layering method. Select 2-3 year old mature branches, perform ring barking 20-30 cm from the branch tip with a width of 2 cm, and wrap with leaf mold and plastic film. Healing and rooting occur in 4-5 months, and in autumn they are cut off and potted.
3. Sowing: Propagation of Rhododendron pulchrum by sowing is best done in April, using indoor pot sowing. The optimum germination temperature is 22-24°C, and germination occurs 10-15 days after sowing, but the seedlings grow slowly.
Cultivation Methods of Rhododendron pulchrum
1. Potting soil: Rhododendron pulchrum prefers acidic soil and requires loose, well-drained soil rich in humus. Take 4 parts humus soil, 2 parts old potting soil, and 1 part each of sandy soil, burnt soil, and sawdust, add an appropriate amount of cake fertilizer, mix well, and pile and compost for half a month before use.
2. Potting up: When potting up Rhododendron pulchrum, keep more of the original soil around the seedlings and minimize root damage. Appropriately shorten excessively long roots, and for larger plants, prune the upper branches. First cover the drainage hole at the bottom of the flower pot with overlapping broken tiles, lay a layer of coarse-grained soil as a drainage layer, fill part of the culture soil in the center, then place the plant in the pot and straighten it, add soil and firm it down. The planting depth should be equivalent to the original depth at which the seedling was lifted from the ground, then water thoroughly.
3. Watering: Rhododendron pulchrum is afraid of both drought and waterlogging. From the end of November to the first and middle ten days of February of the following year, most open-ground potted Splendid Rhododendrons are in a dormant or semi-dormant state, so water appropriately according to the dry and wet condition of the potting soil. In late February, when the temperature rises and flower buds and leaf buds begin to sprout, appropriately increase the frequency of watering. From March to June is the vigorous growth period of new shoots, when water demand increases, so the frequency of watering should be increased accordingly. From July to September, when temperatures are high, water every day. After October, the amount of watering can be reduced.
4. Fertilizing: Rhododendron pulchrum does not like heavy fertilizer; apply dilute fertilizer frequently. Use long-acting fertilizers as base fertilizer, such as organic fertilizers like cake fertilizer, bone meal, and dry aged manure, buried in the potting soil when potting up, repotting, or in winter. Use quick-acting fertilizers as top dressing, such as organic fertilizer like human manure or nitrogen, phosphorus, and potassium chemical fertilizers. From the beginning of spring to before flowering, apply phosphorus and potassium fertilizer 1-2 times a month, and stop fertilizing when flowering. After the weather turns cool in autumn, apply liquid fertilizer mainly of phosphorus fertilizer 1-2 times, and stop top dressing after winter begins.
5. Pruning: During the growing period, Rhododendron pulchrum must be pinched back and pruned, removing dead branches and sprouting tiller branches, which is conducive to balanced development of the tree shape. For ground planting, choose acidic soil in a high, dry location with ample sunlight and deep soil layers. Apply fertilizer once each before and after flowering every year, cut out overly dense inner branches, shorten leggy branches, and cut off dead and diseased branches to ensure that Rhododendron pulchrum can grow robustly.