Open Grow Guide

Air layering

By Open Grow Guide Updated

An air layer grows roots on a branch while it is still attached to the parent plant. You wound the bark, wrap the wound in moist sphagnum moss, and hold the moss in place with foil. Once roots have covered the moss, you cut the rooted stem off and pot it. Air layering, also called marcottage, is the most common propagation method used in Florida for longan. You can make multiple air layers on one parent plant at the same time. This guide covers timing, materials, each step in order, and the mistakes to avoid.

When to do it

Choose a time when the plant is actively growing. At that stage the bark peels away easily once you make the vertical cut. Layers removed during the growing season should be potted in containers and hardened much like rooted cuttings. Layers harvested in winter can usually be transplanted directly into the landscape if adequate care is provided. Plan a first look for roots after three to four weeks. Roots become visible through the plastic anywhere from 1 month to a year later, depending upon plant species and time of year. For longan, air layer roots form within 10 to 12 weeks. Air layered longan trees may bear fruit 2 to 3 years after planting, and air-layered or grafted lychee trees begin to bear fruit in 3 to 5 years.

What you need

Gather a knife, moist sphagnum moss soaked in water and drained, and aluminum foil sheets about 5 by 8 inches. Your tools should be sharp and clean, and your propagation media sterilized. The medium should be sterile to prevent disease. Plan on about a handful of sphagnum moss, squeezed so it is moist but not wet. For a houseplant, plastic wrap can cover the moss around the sliced stem. The aluminum foil goes over the moss ball to prevent excessive heat buildup under the plastic. A small chip of wood or a toothpick keeps the incision open if you use the slanting cut. A bucket of water holds the freshly cut layer until you can get it to a potting area. A two-gallon container holds the layer when you pot it, with the roots placed below the soil line. A weak solution of 20-20-20 fertilizer is an optional liquid drench after watering. Rooting hormone is not necessary for most air layers.

Step by step

  1. Step 1

    Time the air layer for active growth

    Make the cut while the plant is actively growing, since the bark then peels away easily once you make the vertical cut.

  2. Step 2

    Prepare clean, sterile tools and medium

    Use a sharp, clean knife and a sterilized propagation medium so the wound stays free of disease.

  3. Step 3

    Gather your materials before you start

    You will need a knife, moist sphagnum moss that has been soaked and drained, and sheets of aluminum foil about 5 by 8 inches (13 by 20 cm).

  4. Step 4

    Choose the branch you will layer

    Pick a vertical branch about the width of a pencil.

  5. Step 5

    Make the first ring cut

    Cut a ring through the bark about 12 inches (30 cm) down from the tip of the branch.

  6. Step 6

    Cut through the bark only

    Ring only the bark with the knife, and do not cut into the woody part of the branch underneath.

  7. Step 7

    Make the second ring cut and peel the bark away

    Cut a second ring about 1 1/2 inches (4 cm) from the first ring, then join the two rings with a vertical cut to peel away the bark and leave a ring of exposed wood.

  8. Step 8

    Scrape away the cambium layer

    Gently scrape the exposed wood to remove the cambium, since any cambium left on the wood will let the bark heal over before roots can form.

  9. Step 9

    Match the cut to the branch size

    An air layer can span wood anywhere from about 12 inches (30 cm) long and 1/4 inch (0.6 cm) thick up to 3 feet (0.9 m) long and 7 inches (18 cm) thick.

  10. Step 10

    Pack moss around the wound

    Take about a handful of sphagnum moss, squeeze it so it is moist but not dripping wet, and pack it around the wound.

  11. Step 11

    Adapt the method for a houseplant

    For a houseplant, you can instead slice a portion of the stem, set moist moss around the wound, and cover the moss with plastic wrap.

  12. Step 12

    Hold the moss in place with foil

    Wrap the moss in aluminum foil and twist it closed at both the top and the bottom of the wrapped area.

  13. Step 13

    Keep the area warm enough to root

    Hold the rooting area at about 75 to 80°F (24 to 27°C) to encourage rooting.

  14. Step 14

    Check for roots after a few weeks

    Gently pull back the foil after three to four weeks to look for roots.

  15. Step 15

    Wait until roots cover the moss

    The air layer is ready to come off the parent plant once roots have covered the sphagnum moss.

  16. Step 16

    Cut the rooted piece free

    Cut the rooted stem off just below the sphagnum-root mass, or for a houseplant, just below where the new roots have formed.

  17. Step 17

    Keep the cutting moist until you can pot it

    Place the freshly cut air layer in a bucket of water until you can get it to a potting area.

  18. Step 18

    Pot the new plant correctly

    Pot the air layer in a two-gallon container with the roots placed below the soil line.

  19. Step 19

    Water and feed the new plant

    Water the newly potted air layer, then optionally give it a liquid drench of a weak 20-20-20 fertilizer solution.

  20. Step 20

    Protect the newly potted plant while it adjusts

    Keep it in a protected area; a mist bench helps but matters less here than it does for rooting cuttings.

  21. Step 21

    Plant a houseplant layer right away

    For a houseplant air layer, plant the newly rooted piece immediately after you cut it off.

  22. Step 22

    Move the plant on once it fills its pot

    Once the new container is filled with roots, you can repot the air layer or plant it in the ground.

Mistakes to avoid

Several things can go wrong with a layer. If you leave the cambium on the exposed wood, the bark will regrow and roots will not form. Ring only the bark, and do not cut into the woody portion of the branch. With the slanting cut, going too deep may break the branch. An incision with no wood chip or toothpick holding it open can heal over. Placing the enclosed layer in full sun makes it overheat. Keep it in diffused light instead. Leaving off the foil lets excessive heat build up under the plastic. Potting a layer that has not been hardened is risky, because plants that are not adequately hardened are less likely to survive transplanting. Some plants resist the method altogether. Air layering has not proved successful for carambola, due to poor root development. Marcottage has not been an effective propagation method for sapodilla.

How this page was made

  • Written with AI assistance from the sources listed on this page. AI is never the source of a fact.

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