Air-Layering: plant propagation part 3

What are air layers?

Air-layers are vegetatively propagated plants that result from rooting plant branches.

Potted plum and pear trees — Acclimatised plum and quince air-layers two weeks after harvesting.

Advantages of air-layers

The air-layer is true to type; has the exact genetic composition as the parent plant, so fruit trees produce the same type and quality fruits as the parent tree.
The air layers are the exact age of the parent plant harvested, so they start bearing a small fruit crop once well established.
The roots grow as rapidly as the canopy, making them less vulnerable to drought stress when established.
The air-layered branch continues to grow and fruit while on the parent plant. However, removing large branches during harvesting reduced yields for the parent plant.

Two large potted Plum air layers — Well-trained plum air-layers ready to bear fruit within a year of harvesting. The strong roots are growing outside the polythene bags.

What is the difference between air layers and cuttings or grafted fruit trees?

Air layers do not need a rootstock to be propagated. However, it is a valuable propagation technique when rootstocks are unavailable, especially with rare or exotic plants. The lack of rootstocks also applies to plants propagated from cuttings, although larger than cuttings, so they support a good crop of fruits earlier.
Air-layers do not get dieback or graft rejection that may occur with grafted plants, especially in harsh climates.
They are thicker and bigger than cuttings and grafted trees of the same age, so they carry a more significant crop than the other vegetatively propagated plants of the same age.
Air-layering requires more skill than cuttings and grafting for some gardeners, although some people may find grafting plants harder.

Thicker and larger air-layers growing among rooting cuttings that produce smaller plants at the same age. When fully grown, the cuttings will have the same advantage as the air layers but take two to three years longer to develop thicker plants.

Disadvantages of Air-layers

They may lose some of the benefits of the rootstocks, such as dwarfing effect, pest and drought resistance that may be found in the rootstock genes. However, the roots of most air layers compensate for this deficit.
Not all plants can be air-layered as some plants are resistant to forming ectopic roots.
Infections may affect the parent tree if not performed or harvested correctly.
Air layers may take a long time to root and acclimatise, ranging from two months to a year. Only a few plants can be propagated in this way in a year.

Rooted air layer — A well-rooted air layer takes skill and time to develop good roots that are not damaged during the separation from the mother plant and potting. Practising is the best way to improve success rates.

When is the best time to air–layer plants?

In the subtropics, air layering is okay for any time of year and day. The plants will form roots at any time. Air layers can survive on the mother tree for years until one decides to harvest them.

When is the best time to harvest air–layer plants?

However, when temperate trees are dormant, harvesting air layers may be most successful, as they acclimatise more easily. The ever-green plants are best harvested in the rainy season when humidity levels are higher. However, there must be a balance to avoid cutting tree branches when it rains continuously to avoid introducing fungal infections and other diseases in the parent tree. Consider sealing the wound on the parent tree with a plant sealant or Vaseline petroleum gel.

Why are air layers so expensive?

Air layers are usually larger, taking time and expertise to propagate at the expense of a large chunk of the parent tree. However, they will bear fruits earlier that are true to type, even after dying down to the root when established. Not surprisingly, these sacrifices and benefits come at a price.

The air-layered Eureka lemon tree bore a small crop in its first year. A grafted tree would not be thick enough to carry good-sized fruits.

What is marcotting?

Marcotting is an air-layering technique in which a branch is bent into the ground and covered with soil until it roots. It is ideal for vines, especially berries and low-hanging branches. It is more natural and may occur spontaneously.

Let us know in the comments if you want us to do more on air layering. Visit our store for air-layered and marcotted edible plants. #LoveHomeGrown