It is fairly easy to propagate Rhododendrons and Azaleas for the home garden. We provide a brief guide to propagating Rhododendrons by Cuttings and Layering and other methods
Rhododendrons are actually fairly easy to propagate and the two techniques used are by taking cuttings and by layering.
Propagating Rhododendrons by layering
Layering is actually a natural sort of way to make new plants, Rhododendrons will do it themselves in the natural environment when smaller branches come to rest on the ground.
Plants send out new roots at the point of contact between branch and soil, you will probably find this happening in many older gardens.
You can speed up this method of propagation by helping the plant.
- Find a branch that will easily touch the ground, provide it with a rich humus filled soil, and make a wound in the lower side of the branch.
- You will need to secure the branch to the ground to stop it moving around, use some metal tent pegs, wire or even a rock, the idea is that the branch does not move around.
- You can speed things up by using one of the rooting hormones, either powder or liquid.
- Make sure that the branch does not move around and be patient, try not to even look for new roots for 18 months to 2 years.
- Once new roots are formed, cut the new plant away from the old and its ready to pot up or plant out.
Or maybe try aerial layering.
This is where peat moss or a similar moisture retentive product is wrapped around a branch and kept moist, you can use plastic to wrap the moss or you might find special aerial rooting pots at some specialist nurseries.
You still need to ‘wound’ the plant and use the rooting hormone, you also need to keep the moss moist.
How long will this take, from 6 months to a year.
Propagating Rhododendrons from cuttings
Probably the best way to grow a number of new plants at once, you can do this when plants are in active growth, from spring to late summer early autumn.
You will need a potting medium that is humus rich and water retentive, but open as well.
Try smaller sized cuttings from wood that is one year old, go for wood that is less than 6″ long with leaves at the top.
Cut at an angle using clean Secateurs (this prevents disease), again use a rooting hormone powder or liquid and place cuttings firmly into the mix, water in well and provide a humid environment, either in a mini greenhouse or by placing a plastic cover over the cutting.
Remember to trim back the leaves by 1/3 keep moist and be patient.
Once new growth appears remove the plastic cover and leave in the pot for at least another 3 months.
How long will this method take, from 3 months to 9 months.
Other propagation methods
Growing from seed.
Yes you can, but you never know exactly what sort of rhododendron you will be getting, it could be a great new plant, or it could be a throw back to an original species. It is really only the species that come close to reproducing the same plants from seed.
If you want thousands of identical plants, or just have a scientific bent and want to experiment, then go for it. Use a tissue culture lab. We suggest you do a course in tissue culture first if you want to do it yourself.