The Monstera deliciosa, admired for its large, fenestrated leaves, is a popular houseplant that naturally develops aerial roots. These adventitious roots emerge from the plant’s stem nodes, extending into the air rather than growing beneath the soil surface. When these typically robust projections begin to look thin, dry, and brittle, it signals a change in the plant’s immediate environment. Understanding the causes of this shriveling is the first step toward restoring the plant’s health.
The Functional Role of Aerial Roots
In their native tropical environments, Monstera plants are hemiepiphytes, meaning they begin life on the forest floor and then climb up host trees to seek more sunlight. The primary function of the aerial roots is to serve as anchors, affixing the plant to bark or rock surfaces for structural support as the vine matures. This climbing mechanism allows the plant to grow vertically, which is necessary for the development of its iconic large, split leaves.
These roots also have a secondary function, drawing minor amounts of moisture and nutrients from the humid air and any organic debris they encounter. While the subterranean roots handle the majority of water and nutrient uptake from the soil, the aerial roots contribute to the plant’s overall hydration. A healthy, actively growing aerial root appears plump, smooth, and sometimes has a light-colored, growing tip.
Environmental Factors Leading to Dehydration
The most frequent cause of shriveled aerial roots is a lack of moisture in the surrounding air. Aerial roots are highly susceptible to desiccation because they are acclimated to the consistently high humidity of a rainforest understory, often requiring levels above 60% to thrive. Standard indoor environments, especially when central heating is active, often have humidity levels well below this threshold. When atmospheric moisture is low, the roots lose water quickly through evaporation, causing them to dry out and become brittle. This dehydration is often exacerbated when the plant is positioned near a heating vent or an air conditioning unit, which blows dry air directly onto the exposed roots.
Shriveling can also be a secondary indicator of insufficient watering of the main root system. If the soil-bound roots are not receiving adequate moisture, the plant prioritizes water for its leaves and stem, diverting resources away from the aerial roots. Since these roots are the most exposed part of the plant, they are often the first structures to exhibit signs of internal water stress by drying up.
Aerial roots, particularly older ones, can naturally transition into a woody, brown, and less flexible state over time. While this change is part of the plant’s maturation, it can sometimes be mistaken for shriveling from dehydration. Physical damage, such as a root being accidentally bent or snapped, will also cause the distal portion to dry out and shrivel.
Reviving Shriveling Roots and Promoting Health
To restore shriveling aerial roots, the primary focus must be on increasing immediate, localized humidity. Positioning a dedicated electric humidifier near the plant is the most effective method for maintaining a consistent humidity level above 50%. A less intense approach involves placing the plant on a pebble tray filled with water, ensuring the pot sits above the water line, allowing evaporation to create a localized humid microclimate.
The health of the aerial roots is directly linked to the plant’s overall hydration, making a review of the watering schedule necessary. Before watering, check that the top two inches of the potting mix feel dry to the touch to prevent overwatering. Consistent, deep watering ensures that the primary roots are functioning optimally, which then allows the plant to support the aerial structures.
Guiding the aerial roots toward a source of sustained moisture is another practical solution. Using a moss pole or coir pole and keeping it consistently damp encourages the aerial roots to attach to and penetrate the surface. Once inside the moist medium, the roots transition from purely anchoring structures to absorptive ones, providing the plant with additional water and nutrients.
Severely shriveled roots that are completely dry, thin, and brittle will not recover their plump appearance. If a root is clearly dead and visually distracting, it can be pruned using clean, sterilized shears, cutting back to the healthy tissue near the stem. If the root still has some flexibility or a healthy base, it is best to leave it undisturbed, as it may still offer structural support or attempt to regrow under improved conditions.