What are the propagation methods for rhododendrons? A detailed introduction to several approaches

Seeing the brilliance of rhododendrons has stirred the desire in many friends to grow them. So, is rhododendron propagation easy? What propagation methods are there for rhododendrons? There really are quite a few methods. This article aims to introduce some of the commonly used ones for reference.

Rhododendrons can be propagated by five methods: cuttings, grafting, layering, division, and seed sowing, among which cuttings are the most common. Cutting propagation produces the largest number of plants, while layering produces seedlings fastest; grafting is the most complicated, and is only used for varieties that are difficult to root from cuttings; seed sowing is mainly used for breeding new varieties.

1. Cutting propagation

This method is the most widely used, with the advantages of simple operation, high survival rate, rapid growth, and stable characteristics.

① Time: for Western azaleas (Rhododendron hybrids), late May to early June; for Hairy azaleas (Rhododendron pulchrum), early to mid-June; for Spring azaleas and Summer azaleas, mid to late June. At this time the branches are moderately mature, and the climate is warm and humid.

② Cuttings: take current-year branches that have just become woody, snap them off with a heel, trim the frayed end smooth, remove the lower leaves, keep 3 to 5 leaves at the top, and keep them moist until planting.

③ Cutting management: the cutting medium can be orchid soil, alpine humus soil, yellow subsoil, vermiculite, etc. The insertion depth should be 1/3 to 1/2 of the cutting length. After inserting, spray thoroughly with water, cover with plastic film to retain moisture, provide appropriate shade, and keep the medium moist at all times within one month. Hairy azaleas, Spring azaleas, and Summer azaleas will root in about one month, while Western azaleas take about 60 to 70 days.

2. Grafting

One rootstock can be grafted with multiple scions and multiple varieties, growing fast, with good plant form and a high survival rate.

① Time: between May and June, using the tender shoot cleft grafting or side grafting method.

② Rootstock: choose 2-year-old Hairy azaleas, requiring the new shoots and scions to match in thickness; the best rootstock varieties are the Hairy azalea cultivars "Yu Hudie" (Jade Butterfly) and "Zi Hudie" (Purple Butterfly).

③ Scions: from the mother plant of a Western azalea, cut 3 cm to 4 cm long tender shoots, remove the lower leaves, keep 3 to 4 small leaves at the tip, and cut the base into a wedge shape with a blade, with the cut surface about 0.5 cm to 1.0 cm long. 5. Grafting management: cut off the current-year new shoot of the Hairy azalea at 2 cm to 3 cm, remove the leaves at that position, make a 1 cm vertical cut, insert the wedge-shaped end of the scion, align the cambium layers, bind the joint with plastic film tape, and put a plastic bag over it, tying the opening to retain moisture; place it under a shade shed, avoiding direct sunlight and scorching. Seven days after grafting, as long as there are fine water droplets inside the bag and the scion does not wilt, it may have survived; remove the bag after 2 months, and untie the binding tape the following spring.

If you want to grow rhododendrons but do not want to buy a whole potted plant from the flower market, you might try the two most commonly used propagation methods above. But be sure to follow the timing and propagation requirements described.