How to Propagate a Plant

What is 'Propagation'?

Propagation is a method used on plants where you can grow a whole new plant from the 'cutting' or node of the existing plant

(Propagation definition: The breeding of specimens from the parent plant stock)

What propagation method to use?

There are a ton of ways to successfully propagate a cutting plant into a new plant! All of the methods listed here can work, but each have pros and cons and will take some trial and error to find the perfect method for each plant.

When choosing a method of propagating, consider the things your cutting needs to grow roots and avoid rot:

Moisture keeps your plant alive without roots and encourages root growth. High humidity around the plant will limit water loss. Airflow is important in a high humidity environment to maintain oxygen around roots and prevent root rot.

To avoid stem rot, keep the cut ends from the stem as dry as possible, and allow them to callous over. The best way to do this is by suspending them above the propagating medium.

Many people over-compensate to avoid rot and let their roots get too dry while propagating. Dry plant = dead, dehydrated tissue = more rot.

Until the cutting grows roots, you don’t need to add nutrients to the water you use to moisten your propagation medium, because it can’t absorb them. Once roots begin to grow, you can add nutrients to help it grow faster. 

 

METHODS:

Air Layering

Air layering means growing out the aerial roots of your plant into soil roots before cutting it. It can be done with bundles of moss wrapped around the aerial roots, guiding aerial roots into moss on a pole, or placing aerial roots into an additional container of soil or water.

Air layering is the best method of propagating because it allows the cutting to grow roots while still attached to the parent plant. This removes the unrooted phase of propagation, giving your cutting the best possible chance to succeed.

I use this method as often as possible.

Pros: Very low chance of rot. Roots grow faster because the cutting can use energy from the entire plant. Very low chance of leaf or node loss on cuttings.

Cons: Does not work for top cuttings that don’t have aerial roots yet. Does not work for existing rootless cuttings or rehabilitating an entire rootless plant. Makes your mother plant look silly while in progress.

Propagating in Water

Water is the simplest way of propagating. Fill a glass or jar with water, place the cutting in, and replace the water every few days. A fish tank air stone can be added to increase water oxygen levels. I use this method for healthy, low risk cuttings. 

Pros: Can use a clear container to see roots form and check cutting for rot. Water propagation also reduces the risk of the cutting from becoming dehydrated. Very easy to maintain consistent moisture around roots, and no organic matter in the medium to introduce disease. 

Cons: No airflow around roots. Only source of oxygen is what is dissolved in water. More difficult to transition roots grown in water to soil. Hard to keep stem out of water.

Propagating in Soil

Many commercial nurseries that need to produce new plants efficiently just plant the cuttings straight into soil. This method can work, especially with a fresh, healthy cutting, but it has the most downsides out of all the methods. 

I use this method for air layering with plants that are growing horizontally instead of climbing.

Pros: No transplanting required. Plant can benefit from nutrients in soil.

Cons: Hard to maintain consistent moisture. Can’t check on roots forming or see rot. Soil can become anaerobic if overwatered. Organic medium can introduce fungus or disease.

Propagating in Moss

You can also propagate in sphagnum moss in place of soil. Moist moss holds a lot of water, which is great for maintaining humidity around roots while still allowing airflow. A cover, like cling wrap, can be used to hold humidity in the container.

This method can yield great results, but is difficult to execute correctly. People often have issues caused by moss that is too wet or too dry. I use this method for air layering mainly.

Pros: Maintains high moisture and humidity without liquid water. Lightweight and easy to shape around roots. Easier to keep stem out of medium. Roots transition more easily to soil.

Cons: Can easily become too compacted. Hard to maintain consistent moisture. Can’t check on roots forming or see rot. Damaging and time consuming to remove from roots. Organic medium can introduce fungus or disease.

Propagating in Perlite/Leca

Perlite has very similar benefits to water, with the addition of greater airflow. Perlite is absorbent and porous, so it will wick moisture up to areas of the container that are not underwater. Keep the container filled with a small reservoir of water below the level of the stem, and cover the top to hold in humidify around the roots.

You can use any chunky, inorganic material for this method, like pumice or LECA, if you don’t have perlite. Perlite is my preference because it is so lightweight; it is easy to pull out the cutting to check on it without disturbing it too much. Heavier mediums will help the cutting stand up better, however.

Make sure you pick a course perlite (#3 or bigger to minimize dust) without fertilizer. I recommend this perlite:

I use this method for high risk, dehydrated cuttings.

Pros: Easy to maintain consistent moisture around roots. No organic matter in medium to introduce fungus or disease. Minimal damage to roots when removing from perlite. Allows airflow to roots.

Cons: Can’t check on roots forming or see rot.