Aerial roots are specialized roots that grow above the ground. They appear on the sides of stems and often look like small nubs. These roots can look different from one plant to another, but they have similar functions. If you’ve wondered what aerial roots are or if you need help identifying the weird growth on your plant’s stems, this is for you.
The Purpose of Aerial Roots
Roots in the ground serve the purpose of absorbing water and nutrients while also anchoring the plant. The primary function of most above-ground roots is support for the plant, although some also absorb moisture or gases from the air. Climbing plants use these roots to anchor themselves on trees or other plants.
For epiphytic plants, like Orchids, aerial roots are the only roots. In nature, Orchids live up in the tree canopy and depend on their roots to keep them in place while securing water and nutrients.
Do All Plants Have Aerial Roots?
Not all plants have aerial roots, but a lot do. Perhaps the best-known example is the Monstera deliciosa. Mature plants develop thick, rope-like roots that hang down from the stems. Pothos plants have growth nodes that are put to use in nature but, outside of propagation, are seldom necessary for houseplants. Most Philodendrons use their roots to stabilize themselves while climbing. The roots can also propagate new plants.
Christmas Cactus plants have fine propagative roots that resemble tiny hairs but transition into roots during propagation. Plants like Kalanchoe will send out tiny propagative roots when they are rootbound to attempt to break off and create a separate plant. You can trim the branches, including the roots, and create a new plant when you see them.
What to Do With Aerial Roots
Generally, leave the roots alone. Removing or placing them in the soil is usually not helpful to the plant, especially for plants that use these roots to collect moisture or gases from the air. This growth is part of the plant and gives them their unique appearance.
In extreme instances, like for the Monstera deliciosa, the roots can be tucked into a cover pot. Removing them may stunt growth, and they will grow back, so removing them can become an ongoing chore. It’s also worth noting that removing these roots creates an open wound and leaves the plant susceptible to pests and disease.
Most plants with aerial roots, which are also known as propagative roots, can be propagated. Place cuttings with propagative roots in water or soil, and the roots will grow and transition to underground roots. Layering is another propagation technique that takes advantage of propagative roots. Not all aerial roots are propagative roots. Orchids are an example of plants that do not have propagative roots.
Enjoy Your Plants
Aerial roots serve a purpose in nature. They may not always serve a purpose for a houseplant, but they add to the character and charm of houseplants.