Succulents store water in their leaves, stems, or roots, making them resilient in dry conditions. While caring for these plants, you may notice thin, thread-like growths emerging from the stem. These are aerial roots, and their appearance is a common phenomenon that is generally not a sign of immediate danger. They simply indicate the succulent is responding to its immediate environment.
Identifying Aerial Roots and Their Natural Purpose
Aerial roots are adventitious roots, meaning they develop from a non-root part of the plant, such as the stem. They typically present as delicate, fine tendrils that are white or light pink when newly formed. Over time, these roots will naturally dry out, shrivel, and turn brown, which is a normal part of their lifecycle.
The natural function of these above-ground roots is to help the plant survive and spread in its native habitat. One role is stabilization, where the root grows downward to anchor a top-heavy or trailing stem, preventing it from toppling over. They are also important for propagation, as they are pre-formed roots ready to establish a new plant if a piece of the stem breaks off and contacts the soil.
Primary Reasons Succulents Develop Aerial Roots
The appearance of these roots signals that the plant is attempting to compensate for a perceived deficiency in its current growing conditions. One common cause is drought stress, where the succulent is not receiving enough water through its main root system. The plant responds by sprouting aerial roots to actively search for moisture in the surrounding air. This survival mechanism is triggered when the potting mix is allowed to remain dry for too long.
Another frequent trigger is high ambient humidity. In a humid environment, the succulent grows aerial roots to absorb water vapor directly from the air, even if the soil is adequately moist. This can be a sign that the main root system is struggling to function efficiently, possibly due to compacted soil, or early-stage root rot.
A third reason relates to structural instability, often resulting from a lack of sufficient light. When a succulent does not receive enough light, it stretches out in a process called etiolation, resulting in a thin, elongated, and top-heavy stem. The aerial roots grow out from this weak stem to act as supportive props. These roots are seeking physical support for the plant’s stretched structure, not moisture.
Actionable Steps for Dealing with Aerial Roots
The most important step upon noticing aerial roots is to diagnose the underlying environmental cause. If the cause is underwatering, immediately give the succulent a deep soak, ensuring water flows out of the drainage holes to fully rehydrate the soil. Adjust your watering schedule to drench the plant thoroughly and then allow the soil to dry completely between sessions.
If high humidity is the issue, focus on improving air circulation by moving the plant to a location with better ventilation or using a small fan. For stretched or unstable plants, gradually transition them to a spot that receives more intense, bright light to halt the stretching. In cases of severe etiolation, the most effective solution is often to “behead” the plant by cutting the healthy top portion and propagating it.
Physical removal of the aerial roots is entirely a cosmetic choice and is not necessary for the succulent’s health. If you find them unsightly, you can safely remove them by sterilizing a sharp pair of scissors or small trimmers with rubbing alcohol. Simply snip the roots close to the stem without damaging the plant tissue. Addressing the environmental trigger is the only way to prevent new aerial roots from forming.