Air Layering: A Guide to Propagating Plants

Air layering is a method of propagating woody plants that allows you to grow new plants from mature stems without having to remove them from the parent plant. It's a great way to create new plants while also rejuvenating older, overgrown shrubs and trees. In this article, we'll take you through the process of air layering, from selecting the right stem to rooting and planting the new plant.

What is Air Layering?

Air layering is a process of encouraging roots to grow from a stem while it is still attached to the parent plant. This process involves making a small incision in the stem, covering it with rooting hormone and a moist growing medium, and then wrapping it to keep the medium in place and allow for root growth. Once the roots have formed, the stem can be separated from the parent plant and planted as a new plant.

Selecting the Right Stem

The first step in air layering is selecting the right stem. Choose a stem that is mature, healthy, and free of disease. The stem should be between 1 and 2 years old and at least 1 inch in diameter. Additionally, look for a stem that is growing vertically and has a good amount of foliage to ensure that it will be able to produce energy for the new roots to grow.

Making the Cut

Once you have selected the right stem, it's time to make the cut. Choose a spot on the stem that is between 6 and 12 inches from the tip and make a horizontal incision that is 1 to 2 inches long. Be sure to make the incision just above a leaf node, where the leaves attach to the stem. This will help to prevent the cut from drying out too quickly.

Applying Rooting Hormone

After making the cut, it's important to apply rooting hormone to the wound to encourage root growth. There are several different rooting hormones available, including powders, liquids, and gels. Simply follow the instructions on the packaging to apply the rooting hormone to the wound.

Adding the Growing Medium

Next, you'll need to add the growing medium to the wound. The growing medium should be moist and well-draining, such as peat moss, sphagnum moss, or a mixture of the two. You'll want to cover the wound with enough medium to keep it moist, but not so much that it is too heavy and causes the stem to break.

Wrapping the Stem

Once you've added the growing medium, you'll need to wrap the stem to keep the medium in place and allow for root growth. You can use plastic wrap, aluminium foil, or a rooting bag for this step. The wrap should be tight enough to keep the medium in place, but not so tight that it cuts off the stem. You can secure the wrap with tape or a rubber band.

Monitoring and Caring for the New Roots

It's important to keep the growing medium moist during the rooting process. You can mist the medium regularly with water or place the wrapped stem in a plastic bag to create a humid environment. Over time, you should start to see new roots forming around the stem. Once the roots are 1 to 2 inches long, you can gently tug on the stem to see if it has rooted. If the stem resists, it's a good sign that roots have formed and the new plant is ready to be separated from the parent plant.

Separating and Planting the New Plant

Once the new plant has rooted, it's time to separate it from the parent plant. This is usually done by gently twisting the new plant away from the parent plant, taking care not to damage the roots of the new plant. If the new plant is too firmly attached to the parent, a clean and sharp knife can be used to carefully separate it.

Once separated, the new plant should be planted in a pot with well-draining soil, and the soil should be kept moist but not waterlogged. The new plant should be placed in a location with bright, indirect light, and the temperature should be kept between 20-25°C (68-77°F). Avoid exposing the new plant to direct sun, as this can cause it to wilt.

In order to help the new plant establish roots, it's a good idea to mist it with water frequently, and to keep the soil moist but not waterlogged. The new plant should be fertilised regularly, following the instructions on the fertiliser package.

As the new plant grows and becomes established, it can be gradually acclimated to outdoor conditions by moving it to a location with increasing amounts of sunlight and exposure to wind and rain. Once the plant is fully acclimated, it can be planted in the garden.

It's important to keep in mind that air layering is not a fast process, and it can take several months for a new plant to be fully formed. However, the results are well worth the wait, as air layering allows you to propagate plants that are otherwise difficult or impossible to propagate by cuttings or seeds. Whether you're an experienced gardener or just starting out, air layering is a valuable technique to have in your toolbox.