It doesn’t take a gardener long to realize that plants can be expensive, and the bank balance can take a hit when you do a lot of growing. If only there were a way to get free plants from the ones you and your friends already have. Well, there is, and it’s called air layering.
With a few simple steps, you can use your existing plants to grow more. It’s also an excellent way to reproduce a plant you love.
Whether you’re a beginner gardener or an experienced one who hasn’t air-layered plants before, I’ll introduce you to this simple method I wished I knew about much sooner than I did.
What Is Air Layering?
Air layering is a method to propagate identical plants from the ones you already have. When you plant seeds, you are planting a new plant, but when using the air layering method, you create a genetic copy of the mother plant.
This propagation method has been around for centuries, but layering also happens in nature, so you are essentially harnessing Mother Nature’s own process.
Natural layering happens when a low stem or branch rests on the ground, and a new root system is formed (ground layering). Because this process is asexual, the genetic material of the old plant is replicated. When you air layer plants, you are copying this process, but you are doing it without touching the stem to the ground.
Instead, you bring a bit of the ground to the upper parts of the plant to trick the plant into thinking the stem is touching the ground.
It’s simple, effective, and free, other than a couple of supplies you’ll need. The process requires that you injure the plant by scraping away the bark, but don’t worry, and it’s won’t impact the health of your plant.
When to Air Layer Your Plants
The best time is in spring or fall. You need to ensure the plant is in a vigorous growth stage, which generally doesn’t happen in winter. Many plants will struggle to form roots in the heat of summer, but if you live in an area with mild summer, add that season to your possibilities.
Evergreens respond much better to air layering in the spring. Deciduous can be either spring or fall.
If this is your first time trying air layering, do it in early spring when the plants are ramping up their growth.
Plants That Can be Air Layered
Essentially, almost any supple, woody plant can be air layered. Some common plants include:
- Tropical house plants
This is just a small list. Try it with any woody plant to see if works. Some respond better than others, but you’ll never know until you try.
How to Air Layer Plants
This is simple, but the more you do it, the more confident you will be! Don’t be afraid to practice in your garden. Here’s what you need:
- A clean and sharp knife (clean this between each plant you air layer to prevent transfer of disease)
- Clear plastic or polyethylene film
- Sphagnum moss
- Ties, string, rubber bands or similar
- Rooting hormone (optional)
The first step is to identify the stems and branches that offer you the best chance of success. Choose a healthy and mature branch or stem. It must be disease-free.
A vigorous one is best, rather than a stem that is stunted or seriously struggling. It should be a minimum of pencil size up to about 3/4 of an inch.
Choose one on the sunny side of the plant as these ones will have more nutrients and energy stored up, therefore are likely to root faster.
Length is important as well. You will start your cut about 15 inches from the tip of the branch or stem. You’ll also need about six inches of branch or stem below the cut.
Steps For Air Layering
If you are a beginner, use larger branches and stems instead of smaller ones.
- Soak a good handful of sphagnum moss in water for at least two hours before you start.
- Find the point 12 to 15 inches below the tip of the branch or stem you are using. Remove the leaves from 3 inches on both sides of this point.
- With a sharp knife, cut a line around the circumference of the branch. You should only cut through the outer bark layer and cambium layer.
- Do the same about 1 1/2 inches below the first. If the gap between cuts is too small, the plant will try to close the bark together again rather than produce roots.
- Join these cuts by making a long cut along the length of the branch.
- Remove the bark in between the first two cuts around the circumference of the branch. You are exposing the inner, soft parts of the branch. This is where new roots will come from.
- Rooting hormone is not essential, but it may give your chances a boost, so by all means, use some. Brush it on the exposed inner layers of the cut.
- Apply a handful of sphagnum moss to the cut area, so it’s completely covered. You can use a little cotton or thin twine to tie it securely but not too tight. Squeeze out excess moisture from the moss as too much moisture will cause decay instead of root development.
- Wrap the moss in plastic and seal both ends. The best method is called a butcher’s seal. Place the plastic over the moss and hold both ends together. Roll these towards the moss until tight, then seal the ends with twine. It should look like a ball of plastic firmly attached to the plant.
- Use waterproof tape to stop excess moisture from getting in the plastic ball.
- Wrap this in tinfoil if the plastic is exposed to full sunlight to prevent algae from forming.
- Don’t let the moss dry out. Loosen the top of the plastic ball and add moisture if necessary. I use a spray bottle to avoid excess additional moisture.
Steps For Air Layering Green Wood
The whole process is the same except for the cut. Green wood is difficult to cut using the above method, so use this variation.
- Locate a leaf node 12 to 15 inches below the tip of the stem.
- 2 inches below the leaf node, turn your knife sideways and make a 3 or 4 or four-inch long cut upwards towards the node, stopping just before the center of the stem. This may make you nervous, but I’ve found the longer cuts to be less inclined to fail. Be careful not to slice your hand open.
- This creates a lip that you can hold open with a piece of a toothpick, a twig, or a pebble. You need to do this because the plant will heal the cut if not held open.
- Cover with moss and plastic as described above.
- Consider staking the branch or stem that you are air layering to prevent breakage.
Removing a Newly Air Layered Plant
Check under the plastic every two weeks or so. You want to be able to see a mass of new roots through the plastic before you remove the plant.
There is no hard-and-fast rule over rooting times. It depends on the plant type, the season, the sunshine, and luck. Don’t panic and undo the plastic ball if roots don’t form. Sometimes they take a while. I had one take six months, but have been successful between four and 12 weeks.
If you have air layered a plant and it’s not complete by the time winter has come, you can overwinter it. Add more sphagnum moss around it and wrap it in black plastic.
When you are confident there is a mass of roots under the plastic, it’s time to remove your new plant.
Prepare a container with a potting mix by filling it half to 3/4 full. Cut the newly formed plant from the mother plant with sharp shears about 1 to 2 inches below the plastic ball. Carefully remove the plastic without disturbing the moss ball or roots and place it into the container.
Fill the container with more potting mix and tamp down. Use a stake on either side of the plant to help hold it in place.
Water well and keep the medium moist, but not soaking.
Place a clear plastic tent over the plant using the stakes to stop it from resting on the foliage. Keep this in place for up to ten days to help keep it warm while the roots develop and strengthen. Then, remove it and water the plant regularly until it is ready to go into the garden or a larger container.