How to propagate plants from hardwood cuttings
In our last post, we talked about propagating plants. However, you can also propagate trees and more woody plants, by using hardwood cuttings.
Hardwood cuttings don’t need a high humidity environment to get to work, and can really be left to do their thing. So in this post we’re going to show you the method for propagating from hardwood cuttings.
What's the difference between hardwood and softwood cuttings?
The difference between hardwood and softwood cuttings is when they are cut from the plant.
During the growing period, while the plant is nice and leafy, softwood cuttings can be taken. You don’t want the cuttings drying out, so you’ll need to keep the cuttings in a high humidity environment until the new roots develop as water will escape from the leaves.
For hardwood cuttings, you can take these when the plant has lost its leaves during the winter, when the plant is dormant from its growing cycle.
How to propagate with hardwood cuttings?
Hardwood cutting propagation is a great way to grow fruit trees like pomegranates and figs, or vine fruits like grapes, currants and kiwi.
Take your cuttings
The best time to take the cuttings is in early autumn to late winter. That way, all the leaves will have fallen. Your cuttings should be around as thick as a pencil. The cutting shouldn’t be soft and green, but more mature and wood-like.
If there are still green growths on the cutting, these can be removed too. The best chance for root development is to take a cutting from where the newest wood joins the older wood of your plant.
Cut them to size
Hardwood cuttings tend to be quite long, meaning they often take longer to develop roots. A longer cutting means your new plant will have larger food reserves to keep it going during the winter. To trim the cutting from the tree, make a horizontal cut below the lowest bud near the base of the twig or branch (the cut should be around 6mm).
Then, at 15-20cm up the cutting, trim a sloping cut away from the buds.
Wound the cuttings
Certain plants that are difficult to root need to be wounded. This helps to promote new root development. To ‘wound’ the cutting, you simply make a cut on either side of the stem at the base. This exposes more cambium (the green layer under the bark). Using the new cuts, you should then be able to scrape off the bark to create a green tip at the base of your cutting.
Add a root hormone
If you’re planning to use fertilizers or hormones, it’s at this stage you’ll add it. Treating a cutting with hormones can increase the chances of successful propagation by stimulating root growth. Using hormones is recommended for species that are a little harder to root.
To treat the cutting, you can just dip the base into the hormone powder.
Prepare your propagation medium
There are two ways to propagate hardwood cuttings: Either in a slit trench, or in a container.
A slit trench can be made outside by creating a slit in the soil with a spade. If you want to propagate the plants indoors, you can use a container of water or potting soil.
Even though we’re working with hardwood cuttings, there’s still the chance that the cuttings will dry out even more. So, if you’re using soil as your propagating medium, it’s better to place the cutting below the surface of the soil. Leave the top few buds above soil level. As a general rule of thumb, the bottom two thirds of the plant should be under the soil. Each cutting should be around 5cm apart.
Water the propagating medium but don’t overwater – as this can sometimes lead to rotting. If possible, the container should be kept somewhere cold to help speed up root formation. In the Spring, you will then have new rooted cuttings to plant!
In the slit trench, the cutting should be two-thirds below the soil with the soil then pressed down lightly around it.
You can then go ahead and water the soil, which will stay moist during the cold, Winter period. Over the next year, your cuttings will start to root and you’ll be able to plant them properly next Autumn.
How to propagate grape vines?
As mentioned above, propagating with hardwood cuttings works for fruit trees and vines. However, grape vines are slightly different.
When creating a cutting, you’ll only need around 3-4 buds. Push the cutting into the soil so that two of the buds are under the soil, while the others sit above.
There’s also the option to take a shorter cutting that only has one bud. These are known as ‘vine eyes’ and don’t root as easily as longer cuttings.
To trim the cutting, you’ll need a cut around 6mm above the bud and another 5cm below it. Vine cuttings can be placed all in one container and left to grow for a year. The cuttings will be ready to be planted the following Spring.
While propagating seems confusing at first, it’s actually very easy. If you’ve pruned your fruit trees over the winter, you’ll have plenty of cuttings to try with. Let us know how you get on!