Air Layering Is an Easy Way to Multiply Houseplants—Here’s How

Over time, some houseplants get too big for their space, or they lose their lower leaves and look too tall, leggy, and scraggly. Instead of tossing your favorite ficus or philodendron, you can air layer it. Air layering lets a new set of roots grow higher on a stem or branch. Once established, you can cut off the stem below them and pot up the newly shortened plant.

Air layering is also a quick and easy way to make more plants. This propagation method works on many tropical plants often grown indoors, including weeping fig, rubber plant, hibiscus, schefflera, dracaena, dieffenbachia, pothos, and crotons. Here's what you need to know to air layer your houseplants successfully.

Benefits of Air Layering

Planting seeds is one way to propagate plants, but it's not the most reliable. Hybrid seeds don't always grow true-to-type, which means the baby plants may not look like the parent. Stem cuttings can die, and hardwood cuttings won't always root. Many plants simply can't be propagated by leaf cuttings.

Air layering creates an identical copy, or clone. It involves making a small cut in the plant you want to duplicate, but the damage is minor because you're not cutting off entire stems or leaves. A moistened growing medium is then placed over the cut so new roots can develop. While they're growing, the parent plant keeps growing, too. Researchers have found plants grown from air layering often grow to a desirable size faster, and are usually stronger, than plants propagated by other methods.

When Is the Best Time for Air Layering?

Sometimes air layering occurs in nature when a plant stem or branch hangs so low it contacts the ground and takes root. Your potted indoor plants need a little help. Spring or mid-summer is the best time of year to air layer your houseplants. Use stems that grew the previous year if propagating with this method in the spring. If you propagate in the summer, use the current year's stems.

How to Air Layer Indoor Plants

You'll need a few tools:

• Clean and sharp knife
• Moistened sphagnum moss
• Clear plastic wrap
• Powdered rooting hormone
• Toothpick
• Garden twine or floral ties

First, decide where you want the new roots to form on the stem. Remove any leaves from that spot. Then use your knife to make an upward slice, 1½ to 2 inches long, at about a 30-degree angle. Cut one-third to two-thirds of the way through the stem or branch, but not all the way through.

Use a toothpick to hold the cut open and sprinkle or brush powdered rooting hormone over it. Place damp sphagnum moss over the area and wrap it up with a piece of clear plastic wrap or a clear plastic bag. Use twine or floral ties to hold everything in place. Once a week, check the moss. If drying out, moisten it with water from a spray bottle.

Depending on the type of plant you're propagating, new roots will develop in two weeks to three months. Wait until you can see them and they're a couple of inches long before you remove the plastic. Leave the moss in place while you cut off the unwanted part of the stem just below the new roots. Don't remove the moss until you're ready to pot up your shortened plant. It'll help protect the young roots.

How to Air Layer Woody-Stemmed Houseplants

Air layering woody plants, or plants that become woody as they age, is slightly different. Instead of slicing into a stem or branch, you'll need to peel off a ring of bark. It's best to do this in the spring and summer when the plant is actively growing.

Start by measuring the diameter of the branch or stem you want to propagate. Then make two parallel cuts 12 to 24 inches from the tip of the branch. The distance between the parallel cuts should equal 1 ½ to 2 times the diameter of the branch. Remove all the bark between the cuts. This leaves a ring around the branch without any bark on it.

Sometimes the cambium layer, which is the green tissue just under the bark, comes off with the bark. If it doesn't, scrape it off with your knife. Then brush powdered rooting hormone over the scraped area.

Put moist sphagnum moss over the ringed area, cover it with clear plastic wrap, and secure it with twine or floral ties. When new roots form and grow a couple of inches long, remove the plastic and leave the moss in place until you pot up the new plant.