Propagating Orchids from Aerial Roots

Propagating Orchids from Aerial Roots

An orchid’s aerial roots are the ones that grow from the main stem of the plant, and you can use these aerial roots to propagate your orchid. You need to use a sterilized pair of scissors to cut them off the parent plant and place them in their own pot. After a few weeks, the roots will establish themselves in the soil, from which a new plant will grow.

In this article, we will dive deeper into how the propagation of orchids using aerial roots. If you would like to learn more about this process, just keep reading.

Is it possible to propagate orchids from aerial roots?

Yes, propagating orchids from aerial roots is possible, but only for a handful of genuses, including paphiopedilum, cattleya and cymbidium.

If the orchid falls to one side and has a hard time staying upright, you can cut off the top of the stem that has aerial roots. Use a sterilized knife to cut it off, then let it dry out, sprinkle it with charcoal and plant it in a new container. Do not throw away the leftover stump, because new growth will soon appear on it, too.

Why are aerial roots so important?

Aerial roots are important to an orchid’s growth because these plants are epiphytic. Epiphytes grow on the bark of trees or other plants, without the support of traditional growing media, and use their aerial roots to absorb water and nutrients from the air around them.

These roots can also help to anchor them to the bark of the tree, and to reach sources of light that the plant needs to survive.

If you notice that your orchid has a lot of aerial roots, this may be a sign that the plant needs to be repotted. An abundance of aerial roots is often observed when the roots in the soil or potting medium are compromised. Putting out more aerial roots than usual is the plant’s way of compensating for its unhealthy roots under the soil.

Your plant will also try to produce more aerial roots if it does not feel very stable in its container or wherever it is situated. This is commonly seen when the plant has flower spikes supporting so many flowers that it can no longer carry the weight. The more unbalanced the plant, the more aerial roots it will produce to anchor itself.

If you are repotting a plant that has aerial roots, do not bury the aerial roots in the potting medium. They can rot if buried in the soil. Air circulation is key when caring for a plant with aerial roots.

Propagating orchids from aerial roots

If you are planning on propagating your orchid using aerial roots, cut these roots off the parent plant using sterilized pruning tools. Prepare pots with specialized orchid potting mix and place each cutting in a pot. Make sure to mist the aerial roots in the potting medium, and never let it dry out completely. After several weeks, new growth will appear. 

Growing a new plant from an aerial root will take quite some time, so you will need to be patient when using this method of propagation.

What are other methods of orchid propagation?

Division

Plant division is a technique preferred by growers of larger orchid species. The parent plant can be divided into several sections and each section can then be grown into a new plant.

Sympodial orchids can be split into sections, with each section containing at least three pseudobulbs. Use a sterilized knife if you need to, or you can simply use your hands to separate the sections from one another. Often the plant will have natural lines that separate each section, so if you can identify these natural divisions, you will have an easier time separating the parts.

After you have successfully separated the sections, remove any dead foliage and repot the sections. You can then continue caring for these new plants in the same way you would a mature orchid.

Back bulbs

Another method of propagation is to use the back bulbs of the orchid. The back bulbs are pseudobulbs whose main purpose is to store water for the plant. They no longer produce flowers or even roots.

You can choose to only remove the back bulb and grow a new plant using this, or you can separate the back bulb while also separating the entire plant into sections.

Plant the back bulb in its own pot and wait a few weeks for it to start rooting. Depending on the species of orchid, the plant can stay dormant inside a back bulb for as long as two years.

This is one of the slowest ways to propagate orchids, but it can be an effective way to grow more of your favorite plants.

Keikis

Keikis are present in monopodial orchids. They are sprout offshoots that grow above the root structure of the plant or on the stem of the parent plant.

Keikis are best used for propagation once they have their own leaves and roots. Make sure the roots are at least a few inches long before thinking of cutting the keiki away from the parent plant.

Stem cuttings

If the stems of your orchid have nodes, you can use them for propagation. This method is used for sympodial orchids.

Wait until the parent plant has finished blooming and the flowers have all fallen off. Choose a stem that is at least 10 inches long, and use sterilized scissors to cut it off at the base. Divide the stem into several sections, making sure that all the sections include at least one node.

Place these sections in a container filled with sphagnum moss. Make sure the moss is damp and never completely dry. Cover the container with a plastic bag to lock in moisture and help increase the humidity. After several weeks, new growth can be observed on the stem cuttings.

How can I repot an orchid that has lots of aerial roots?

Repotting an orchid can be a little trickier than repotting other houseplants.

  1. First, remove the plant from the pot. Do this as carefully as you can because the roots can be easily damaged. If you have to use a knife to loosen the potting medium a bit, then use it with caution. Try to minimize any root damage as much as possible.
  2. After successfully removing the plant from the pot, remove as much of the old potting medium as you can from between the roots. You will not be reusing this potting medium, so dispose of it properly or use it as compost. You can remove the old potting medium by shaking the roots or by using a small tool to clear it from between the roots.
  3. Hold the roots under a tap and let tepid water help wash away the rest of the old potting medium. You can also just let the roots soak in tepid water for 15 minutes. The soaking will help make the roots more flexible while also removing the residual potting medium.
  4. Be careful when soaking the orchid; make sure no water gets into the plant’s stem. This can lead to crown rot, which should be avoided at all costs. If water gets into the stem accidentally, you can soak it up with a paper towel or a cotton pad.
  5. After soaking the roots, you will have a better picture of their current state. You can now see which roots are rotten and which are healthy. Using sterilized tools, remove the brown and black, mushy roots. If you have been caring for the orchid properly, there should be many healthy, green roots left after pruning off the rotten roots.
  6. After removing all the dead or dying roots, spray the healthy roots with a 3% hydrogen peroxide solution in order to clean them further and to kill any pathogens that are still present.
  7. Prepare a new pot that is one size larger than the old one, and that has drainage holes at the bottom. You can opt for a clear pot if you want to be able to view the condition of the roots at any time.
  8. Place the plant in the pot and hold it so that it stands upright in the middle. Fill the spaces around the roots with a potting mix specially made for orchids. Remember not to include the aerial roots when burying the main roots under the potting medium. Do not pack the potting mix too tightly, as this is not good for the plant.
  9. Repotting is a traumatic experience for your plant, so do not water it for a few days afterwards. Give the plant several days to recover first, so that the roots can return to normal and can absorb water and nutrients effectively.

Conclusion

To propagate orchids using aerial roots, you need to cut off some aerial roots from the parent plant. Make sure you use sterilized tools so that you do not risk spreading any diseases.

Place the cut aerial roots in their own pots and keep the potting medium moist, but not damp. Do not let the potting medium dry out completely, as this is not good for the new plants. After a couple of weeks, you should be able to see new growth sprouting from the cuttings. Remember that it will take the new plant a long time before it can fully mature and bloom. Patience is a very important trait when propagating orchids, but it will be worth it in the end.

Image: istockphoto.com / kulbabka