Detailed Guide to Rhododendron Seed Propagation Methods and Steps

Seed propagation is sexual reproduction. Because the seed-setting rate of natural cross-pollination is very low, artificial pollination is generally carried out to increase the seed-setting rate of rhododendrons and obtain more seeds. The main method is: when the rhododendrons are in full bloom, select robust mother plants with good growth and beautiful flower colors, move them to a greenhouse, and on each pot keep 3-4 flowers that are large and bloom early; remove the stamens and the new buds near the flowers so that nutrients are concentrated. When mucus appears on the stigma, dip a new small brush in the pollen of the father plant and apply it several times. One week after pollination, move the pots outdoors and strengthen water and fertilizer management. After about 5-6 months of growth and development, by November to December the fruit can be seen gradually changing from green to brown, and the seeds are then ripe. Immediately pick them, let them dry in the shade, winnow them clean, and place them in a cool, ventilated place.

Rhododendron seeds are very small and are not suitable for long storage, otherwise the germination rate will be low. If they are evergreen rhododendron seeds, they should be sown as soon as they are collected, in pots in a greenhouse; if they are deciduous rhododendron seeds, they can be kept until the next spring for sowing.

For sowing, shallow clay pots are suitable. For the sowing soil, you can dig up loose surface soil with moss from the surface of a shady hillside, pick out stones, and it is best to spray it once with a dilution of 40% formalin plus 100 times water for disinfection, then let it dry. It can also be steamed for 15-25 minutes for disinfection, then sun-dried until half dry before use. Before sowing, first moisten the shallow pot, put a layer of about 2 cm of charcoal crumbs on the bottom, then spread a layer of 5-6 cm thick sterilized soil, scrape it level, press it slightly firm, then evenly distribute the seeds on top, press gently, and do not use a watering can to spray water; it is best to use the method of soaking the pot in water. Cover it with a piece of glass and move it to the greenhouse. When the surface of the pot soil is dry, spray a little water in mist form, but do not spray too much; just keep the pot soil moist at all times.

After sowing, germination generally occurs in 5-6 weeks. When the seedlings have grown 2-3 true leaves, gently pick them out with a small bamboo strip and transplant them separately into other pots. Do not plant them too densely; they should be thinner. After planting, shade them with reed mats and the like; do not let direct sunlight hit them, and do not let rain fall on them. When the seedlings are young and tender, do not fertilize. Wait until the next year when the seedlings have grown to nearly 10 cm tall, then begin applying dilute fertilizer; generally from late spring to early autumn of the second year, they can be transplanted separately as individual plants. In the third year, when the seedlings have grown to 20 cm tall, if they are cultivated well, a few plants can bloom with fresh flowers.