How to propagate rhododendron easily?

Rhododendron is a bush prized for its evergreen foliage and spectacular flowering in a range of colours. Propagating this plant by cuttings allows production of new specimens identical to the mother plant, while saving money. Follow our guide to master this multiplication technique.

A few words about rhododendrons...

Suited to acidic, well-drained soils (these are bushes referred to as heather soil), rhododendron thrives in partial shade, at woodland edges or in borders. Easy to maintain, it copes well with cold and needs little pruning. Ideal for hedging or as a specimen, rhododendron brings an elegant, colourful touch to gardens. There are large rhododendrons (up to 6 m high) and small rhododendrons, perfect for borders or container growing. Azaleas are close to rhododendrons and belong to the same genus. Japanese azaleas have evergreen foliage and Chinese azaleas have deciduous foliage.

For more information, read our detailed fact sheet, Rhododendron: planting, cultivation, pruning and maintenance.

Why propagate rhododendron by cuttings?

Propagation by cuttings allows faithful multiplication of a prized variety, producing young plants identical to the mother plant, unlike sowing which can yield different specimens. It is also an economical and relatively accessible method, ideal for enhancing a garden without buying new plants.

When to propagate rhododendron?

The ideal time to propagate rhododendron by cuttings is from late August to mid-September. At this time, the year's shoots, still semi-woody, offer better rooting ability. Propagation by cuttings is done on semi-woody shoots, as they provide a good balance between flexibility and ripeness, thus promoting faster rooting.

Equipment needed to propagate rhododendron

• A clean, sharp pruning shear for neat cuts.
• Pots or buckets to hold the cuttings.
• A well-draining substrate made of sand, perlite and sphagnum moss to encourage rooting, or a propagation potting compost.
• A root activator (facultative) to stimulate root formation.
• A clear plastic bag or a cut plastic bottle to create a humid atmosphere around the cutting (enclosed cuttings).

Steps for rhododendron propagation by cuttings

1. Selecting the stem: choose a lateral shoot from the year, not in flower, about 10 to 15 cm long. Cuttings should be taken from healthy, vigorous mother plants.
2. Preparing the cutting: remove leaves from the lower third of the stem to limit evapotranspiration. If remaining leaves are large, cut them in half.

1. Application of root activator: dip base of cutting in the root activator to encourage rooting (facultative step).
2. Planting: fill a pot with prepared substrate, make a hole with a pencil, insert the cutting about 2 cm deep, then firm the substrate gently around the stem.
3. Creating a humid atmosphere: cover the pot with a clear plastic bag or a cut plastic bottle to maintain constant humidity.
4. Positioning: place the pot in a bright spot, sheltered from direct sun, at around 15 °C - 20 °C.

Good to know: using a heated mini propagator helps maintain steady temperature and humidity, speeding up rooting of rhododendron cuttings. Also, it is important to renew air regularly under the plastic bag or under the mini propagator to avoid mould formation.

please note: average success rate of propagation by cuttings for rhododendron generally ranges between 30% and 50%, depending on growing conditions and care provided. Layering is often more effective.

After propagation by cuttings: care and maintenance

Oli's note: once roots are well developed, it is recommended to repot the cutting into a larger pot with a rich, well-draining, acidic substrate to promote growth. After a few months of hardening, when the young plant is robust enough, it can be planted outdoors in spring, taking care to respect its needs for acidic soil and partial shade.

Oli's note: once roots are well developed, it is recommended to repot the cutting into a larger pot with a rich, well-draining, acidic substrate to promote growth. After a few months of hardening, when the young plant is robust enough, it can be planted outdoors in spring, taking care to respect its needs for acidic soil and partial shade.

Oli's note: once roots are well developed, it is recommended to repot the cutting into a larger pot with a rich, well-draining, acidic substrate to promote growth. After a few months of hardening, when the young plant is robust enough, it can be planted outdoors in spring, taking care to respect its needs for acidic soil and partial shade.

• Keep substrate slightly moist by watering moderately.
• Ventilate regularly to prevent fungal diseases.
• Cuttings need to be kept undisturbed to root: avoid moving or handling them unnecessarily.
• After about a month, roots should start to develop.
• Keep young plants safe from frost during winter and wait until the following spring to plant them outdoors.

Oli's note: once roots are well developed, it is recommended to repot the cutting into a larger pot with a rich, well-draining, acidic substrate to promote growth. After a few months of hardening, when the young plant is robust enough, it can be planted outdoors in spring, taking care to respect its needs for acidic soil and partial shade.