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How to Propagate Grevilleas (Step-by-Step)

Propagating grevilleas at home is not that difficult if you understand the basics and can provide the right environment.

I used to propagate a lot of grevilleas when I worked as a professional propagator in a production nursery in Queensland. I remember we used to go out in the morning to collect lots of cutting material.

Then, we would head back to the propagation shed and turn all of that material into cuttings.

Of course, being a professional operation, we could give the cuttings the correct environment in order to boost root formation and create new plants.

However, propagating grevilleas at home is not that difficult if you understand the basics and can provide the right environment.

Here’s what you need to do to propagate grevilleas at home.

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Prepare your seedling trays

It’s a good idea to prepare your seedling trays or the pots you plan to use before you take the cuttings. 

For grevilleas, you want a fairly loose mix that is free-draining. You can either use a proprietary seed raising mix or make your own.

To make your own mix, combine equal parts of coco coir, perlite and coarse builder’s sand. This is the ideal mix for these types of plants.

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Fill your seedling trays or pots with the mix and water to make the mix moist.

Taking the cuttings

Take the cuttings from an established plant. You want to select relatively new growth that has just started to firm up a little.

Choosing the right materials is a bit of an art, but once you’ve done it a few times, you’ll know what to look for.

You’ll get the best success if you select new growth that has appeared after the plant has finished flowering and has been pruned back behind the spent flower heads.

In other words, select cuttings from a plant that is currently exhibiting vigorous growth but hasn’t yet started flowering.

Make sure that you cut just below a node. This is the junction where the leaf meets the stem. Cuttings that are around 12 to 15 cm long will work fine. 

Don’t worry if the tip of the cutting is still quite soft. As long as the base of the stem has firmed up a little, you should be fine.

Prepare your cuttings

Once you’ve taken your cuttings, they have to be prepared. To do this, you want to remove any of the lower leaves so that you have a clear section of stem.

Here’s an expert tip I’m going to share with you that will improve your success rate.

With your secateurs or a sharp and clean knife, take a thin sliver of the bark off at least one side of the base of the stem. This creates a wound and exposes the green sapwood inside.

In turn, this will help to stimulate the cutting to produce roots. Be careful when you do this. You don’t want to slip and slice your finger. I know I did this more than once when producing hundreds of cuttings daily.

Dip the base of your cuttings into rooting hormone

In the propagation nursery where I worked, we always used rooting hormone for all the cuttings we prepared. You can buy this from your local garden centre in either liquid, gel or powder form.

We tended to use the liquid because it was relatively easy. Here’s another expert tip I want to share with you.

No matter what type of rooting hormone you’re going to use, never dip your cuttings straight into the bottle or pack. Instead, you want to decant a little of the product into a separate receptacle.

This stops the entire bottle or pack of rooting hormone from becoming contaminated with plant sap or other materials.

For the liquid rooting hormone, we would just pour a little into a small receptacle and place all the cuttings into this until we had enough prepared to put into the seedling trays.

Place your cuttings into the seedling trays

Once you’ve prepared your cuttings and they have been dipped into rooting hormone, it’s time to put them into the seedling trays.

But, don’t just poke them into the soil. Make a hole first using a pencil or a dibber. This way, you won’t wipe off the rooting hormone while you’re placing the cuttings into the mix.

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Create the perfect environment for your grevillea cuttings

For grevilleas to produce roots well, they need two things. Warm soil and consistent moisture. In a professional operation, plants are provided with bottom heat with the use of heated benches.

Plus, propagation sheds have misters installed to come on at predetermined times to keep the mix moist.

While you won’t have this at your disposal at home, you can mimic these conditions quite easily.

If you have a hot-water heater, this can be the ideal place to put your seedling tray so that it gets plenty of bottom heat. If you don’t have this or you can’t put anything on the hot water unit you have, you can actually purchase a seedling heat mat online or from your local garden centre.

The other thing you need to provide your cuttings is a consistently humid environment. You can do this in a number of ways.

You can purchase a small propagation unit that has a seedling tray and a clear cover. The cover is designed to provide a humid environment for your cuttings. 

propagation unit that has a seedling tray and a clear cover | Plant care

As the moisture from the soil evaporates, it creates the humidity that plants like grevilleas need to produce roots successfully. Alternatively, you can cover the cuttings with a plastic bag draped over a frame or the top of a soft drink bottle.

It should take around 4 to 8 weeks for your cuttings to produce new roots. Make sure you prepare a number of cuttings because not all of them will root successfully.

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Annette Hird

Annette Hird is a gardening expert with many years of experience in a range of gardening related positions. She has an Associate Diploma of Applied Science in Horticulture and has worked in a variety of production nurseries, primarily as a propagator. She has also been responsible for a large homestead garden that included lawn care, fruit trees, roses and many other ornamental plants. More recently, Annette has concentrated on improving the garden landscape of the homes that she has lived in and focused a lot of energy on growing edible plants as well. She now enjoys sharing her experience and knowledge with others by writing articles about all facets of gardening and growing plants.

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