If you’ve grown a Monstera before, you may have observed roots that grow above the soil’s surface. Called aerial roots, such roots differ in form and function to the typical roots we think of that grow underground.
In this article, we’ll cover your frequently asked questions about aerial roots. Namely,
- What are aerial roots?
- How they differ from other types of roots; and
- What do to with them.
Monsteras in their native habitat
To understand what aerial roots are, let’s first take a step back and understand how Monsteras behave in their native habitat.
Monstera Deliciosas come from the rainforests of Mexico to Guatemala. Young Monstera seedlings start life near the forest floor, sending runners to look for host trees to climb.
According to the University of Connecticut, Monstera seedlings display negative phototropism. This means they are genetically programmed to seek out the darkest, not brightest, areas to grow. This helps them locate the base of large host trees!
Monsteras develop their first leaves once they find a suitable tree. During this time, they develop thick aerial roots to latch on to their hosts. When fully mature, Monsteras in the wild can grow up to 66 feet (20 meters) tall.
Climbing up trees is part of the Monstera’s natural climbing (epiphytic or hemi-epiphytic) habit. The purpose of climbing is to reach for more light higher in the rainforest canopy.
While seedlings can survive in lower light conditions near the forest floor, as the Monstera grows, it needs more light to support the lush foliage it is known for.
What do aerial roots look like?
Aerial roots form from nodes at the base of a leaf petiole. Nodes look like little knobs or swellings on the stem. They contain genetic material to grow roots, as well as the hormone auxin, which stimulates rooting.
Over time, young roots protrude from the nodes. They are usually green in color. Aerial roots thicken as the grow – giving them strength to support the weight of the plant.
Developed roots turn woody over time, losing their young green coloration.
What role do aerial roots play?
There are 2 critical roles that aerial roots play.
1. They allow this epiphyte (or hemi-epiphyte, to be precise) to climb
Firstly, aerial roots play a crucial role in enabling the Monstera to climb. As the plant matures, nodes near the base of a leaf petiole elongate, forming aerial roots.
These roots quite literally latch on to the base of the host tree, providing structural stability to the climbing plant. Together, the roots hoist the plant upwards towards the light.
Aerial roots can be quite substantial, given their need to anchor the plant onto a host tree.
2. They absorb moisture and nutrients
Secondly, aerial roots absorb moisture and nutrients from the atmosphere around it.
In the wild, Monsteras don’t typically grow in a nice pot of organically rich soil. They make do with what they have: growing in bits of leaf litter, moss and debris near the forest floor.
Aerial roots play a key role in providing the plant with water and nutrition from an alternative source: the atmosphere!
Aerial roots are genetically adapted to have the ability to absorb atmospheric humidity. This helps relieve the plant of water stress during a dry spell.
Aerial roots can also absorb water and nutrients in the way typical roots do. When it rains, debris and leaf litter leach nutrients into the rainwater. Aerial roots can absorb this nutrient-rich water when they come into contact.
What to do with aerial roots
The best thing to do with aerial roots is to lightly drape them against a moss pole to allow them to climb.
Moss poles mimic the function of a host tree, allowing your Monstera to indulge in its natural climbing habit. There are several benefits to providing your plant with climbing support.
With climbing support, Monsteras are found to:
- Grow more rapidly, as they are closer to the sunlight;
- Develop lusher and larger leaves;
- Be healthier.
To support your plant’s climbing habit, use twist ties to gently secure the roots against the pole, so that they can easily latch on.
Once they “grab hold” of the moss pole, you can untie the twist tie and let aerial roots do the rest!
Can you cut off aerial roots?
Yes, you can. If you don’t like the aesthetics of the aerial roots, you can cut them off. Cutting off aerial roots will not harm your plant.
There are just 2 caveats to take note of:
- Aerial roots can (and often will!) re-grow after being cut off. Hemi-epiphytes are genetically programmed to develop aerial roots, so don’t be surprised if you find another air root growing in the same spot!
- Cutting off aerial roots will not damage your plant, but will limit their ability to climb. If you want to keep your plant squarely in its pot, this shouldn’t affect your decision.
How to remove aerial roots
First, be sure to sterilize your gardening tools. We like dipping our gardening shears in 70% isopropyl solution for 45 seconds before and after use.
Then, snip off the aerial root at the base of the stem.
Can you use aerial roots for propagation?
Yes and no. If you cut off an aerial root and place it in water, it will not magically grow into a Monstera.
However, if the aerial root is attached to a leaf stem, you can cut below the node to propagate a new plant. This method of propagation is called stem cuttings. These cuttings can be rooted in water before transferring into a permanent potting mix.
When used in stem cuttings, aerial roots will help the plant establish itself more quickly. This is because they provide water and nutrients to the new plant. New roots can grow directly from the aerial root itself.
Aerial roots are, therefore, a benefit, but not a requirement, for propagation.
What IS key for successful propagation is the node. The node contains the genetic information necessary to grow a new plant, which is why we always cut just BELOW the node when propagating. 🙂
No node = no propagation!
How do I propagate a Monstera?
Stem cuttings are the easiest way to propagate a Monstera.
We like rooting the cuttings in water so that we can observe healthy root development before transferring them into potting mix.
Water Propagation, using Stem Cuttings
- Identify a part of the stem around 5 inches (12cm) long, just below a leaf, with at least 1 nodes. Preferably choose a stem that has aerial roots growing out of it.
- Using clean garden shears, cut just below the node.
- Dip the cut end into a rooting hormone. This stimulates fast growth and reduces the risk of infection.
- Place the stem cutting in a jar filled with room temperature water. You should have at least one node below the surface of the water. No leaves should be submerged.
- Place the jar in a warm location with plenty of bright but indirect light.
- Change the water every few days to keep it fresh and clear.
- In 3-4 weeks, you should see some new roots forming.
- Once the roots reach about 3 inches (7.6cm) long, you can replant your new plant in a well-draining potting mix in its permanent pot.
Aerial roots grow naturally in Monsteras and many other climbing plants. They differ from typical underground roots by anchoring your plant to its host tree, enabling it to reach higher in the canopy.
However, they perform a similar function of delivering water and nutrients to the plant.
You do not need to snip off aerial roots unless you don’t like the look of them. Doing so won’t harm your plant.
But our recommendation is to lightly drape them against a moss pole. Doing so allows your plant to climb. By mimicking its natural climbing habit, Monsteras grow lusher, larger leaves. 🙂
Other Monstera Resources
- Why is my Monstera Leaf not splitting? (top 3 reasons!)
- Caring for your Monstera Adansonii – a complete growing guide
- Wrap up of our 13 favorite Monstera species (w/PHOTOS!)
Deborah is a plant enthusiast and founder of Gardening Collective.