How to take a cutting from a rhododendron

Last updated on March 20th, 2022

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There are a handful of ways that you can propagate your Rhododendrons if you have a plant you are particularly fond of and want to recreate. But taking a Rhododendron cutting is the easiest method, however, results can vary because Rhododendrons don’t take as well as some other evergreen shrubs.

Whether you are an expert grower or brand new, you can easily propagate from Rhododendrons, although you usually have more success with the smaller growing varieties. Taking cuttings is the best way to propagate but of course, if you are going to take Rhododendron cuttings you need to know when to take them, how to take them, and how to propagate them thereafter so that you can continue to enjoy Rhododendrons year after year.

Remember taking Rhododendron cuttings is fairly easy but the success rate is not always that high, so we advise that you take plenty of cuttings. Taking Rhododendron cuttings is a slow process and you usually need to keep them outside in a cold frame for up to two years before they are ready.

Read our fantastic guide on growing Rhododendrons.

When to take your cuttings

When you are taking a Rhododendron cutting you want to do so sometime between the end of July and the middle of August, critically during the warmer summer months. You can take them a little bit later in the year but this is the time you want to aim for if possible.

That being said, you need to be considerate of the new growth and how it feels so that you can ensure you are taking the best possible growth to achieve the highest success rate. For example, if you put the new growth between your fingers and it bends very easily and is otherwise flaccid, this is not the cutting you want to take because it will likely rot rather than root. However, if it is far too rigid and won’t bend it all it is probably too hard or too old to try and propagate. This is the difficult part, choosing cuttings that aren’t too hard yet not too soft and this only comes with experience.

When to take rhododendron cutting - When you are taking a rhododendron cutting you want to do so sometime between the end of July and the middle of August, especially during the warmer summer months.

What you might need

Deep Rootrainers are the workhorse of the range - suitable for propagating and cultivating nearly all plants, trees, shrubs, herbaceous, fruit and vegetables; especially those that have deep fast growing roots such as sweet peas and beans.
Each pack contains: 1 holding tray, 8 books x 4 cells 12cm deep and a clear propagating lid.
Rootrainers encourage vigorous & strong root formation; roots grow straight, avoiding root balls and pot bound plants.
Opening the Rootrainer up in a book-like fashion allows for easy inspection of moisture levels and root progress, as well as satisfyingly easy removal of the young plants.
Tray Size: Length 36cm (15") x Width 22cm (9") x Depth 9cm (3.5").

Agralan Compact Plug Plant Trainer Tray Propagator (Pack of 2)

Grow successful plug plants effortlessly
Integral water reservoir
Simply turn lid to control ventilation, 49 cells for plug plants
Durable and re-usable
Dishwasher safe

VITAX 5RP50 Organic Rooting Powder, Grey, 50 g

The ideal way to start rooted cuttings
Organic rooting fertiliser that stimulates root development
Suitable for edible and ornamental plants
Use with soft, medium and hardwood cuttings

Taking Rhododendron Cuttings

taking the Rhododendron cutting - In order to take your cutting, you want to select growth which can be easily extracted or broken off from old wood, usually wood that is at least 2 years old, meaning the wood from last season. If your new growth has amounted to a single new shoot rather than two or three new shoots, it won't have a heel that you need so this isn't something you want to cut.

Step 1 – Selecting the cutting material

In order to take your cuttings, you want to select growth that can be easily extracted or broken off from old wood, usually wood that is at least 2 years old, meaning the wood from last season. If your new growth has amounted to a single new shoot rather than two or three new shoots, it won’t have the heel that you need so this isn’t something you want to cut.

When selecting your cuttings you should only pick the healthiest of new shoots. Do not pick new growth that is bigger than 15cm in length because it will have a harder time properly establishing a root structure. In most cases, anything larger than 15cm will be too big for any type of propagator as well.

Before you take your cutting you need to make sure that everything else for subsequent propagation is set up and ready to go. This means you can take your cutting and within minutes sit down and prepare it for propagation. You don’t want to take a cutting and then have it wait a few days before moving on to the next step. All these steps need to be taken straight away, one after the other.

Step 2 – Taking the cutting

Once everything is set up take a very sharp knife or pruning secateurs and pull back the heel of the cutting you have selected. If you have cuttings with larger leaves you can cut the leaves in half. The reason you might want to consider this is because cutting them in half means energy won’t be wasted on the leaf surface any more than is necessary, and this forces that energy to be put into the root structure instead. By reducing the overall amount of leaf cover you also reduce the risk of mould or other infections during propagation.

Step 3 – Inserting the cuttings

Once you have your cuttings in hand you should dip the end into a hormone rooting powder and place them directly inside the propagation or misting trays you are using for the subsequent propagation. Roughly one-third of your cutting should be below the surface.

Step 4 – Maintaining the growing conditions

Whatever propagation or misting system you use should be kept at around 18 degrees C throughout the winter and given an adequate misting spray based on the amount of sunlight to which the cuttings are exposed. If you notice that any of your cuttings have gone brown you want to remove them immediately because this is indicative of an infection or fungal rot that can spread if you don’t remove them quickly.

Rhododendrons can take between six and eight months to properly callus and root out to the point where they can be transplanted and grown in a cold frame for a further 12 months, so if you take them during the summer they would likely be ready to transplant by April of the following year.

Step 5 – Success

Assuming everything else goes well, you’re cutting should be propagated by the following season and ready to provide you with additional, beautiful but small Rhododendron.

Once all of your cuttings have properly established a root structure (the following season) you can transplant your Rhododendron into pots or directly into your garden and enjoy them throughout the rest of the spring and summer.