Aerial roots are specialized structures that grow above the soil surface, distinguishing them from typical subterranean roots. These unique roots are a natural adaptation for many plants, particularly those from tropical or humid environments. Understanding their purpose and how they interact with water can benefit plant enthusiasts.
Understanding Aerial Roots
Aerial roots develop from a plant’s stem or branches, extending into the air rather than into soil. Unlike underground roots, which focus on soil-based nutrient and water uptake, aerial roots serve various functions. Many provide physical support and anchoring, allowing plants to cling to structures like trees or trellises as they climb for light. They also absorb moisture and nutrients directly from the air, fog, or rain, crucial for epiphytic plants that grow on others without drawing nutrients.
Common houseplants with prominent aerial roots include aroids like Monstera, Philodendron, and Pothos. Orchids also display distinctive silvery aerial roots, highly efficient at absorbing atmospheric moisture. These roots help plants thrive in challenging conditions, such as climbing high into tree canopies or surviving in waterlogged soils.
Why Place Aerial Roots in Water
Placing aerial roots in water serves several practical purposes for plant care and propagation. One benefit is providing hydration and rejuvenation for struggling or dehydrated plants, as aerial roots absorb water directly. This method can be useful as a temporary solution for a plant in distress, offering quick moisture when the main root system is compromised or the plant experiences transplant shock.
Propagation is another common reason to submerge aerial roots in water. Many vining plants readily develop new roots from their aerial nodes when placed in water, making it a reliable method for creating new plants from cuttings. Beyond practical benefits, placing aerial roots in water can also be for aesthetic display, showcasing the plant’s unique root structure in clear vessels.
Submerging Aerial Roots Properly
When preparing to place aerial roots in water, selecting the right container is important. Clear glass jars or vases allow for easy observation of root development and water levels. Opaque or dark-colored containers, such as amber glass, help prevent algae growth by blocking light.
The quality of water used is another factor for success. Filtered, distilled, or rainwater are suitable options, as they contain fewer impurities and chemicals. If using tap water, allowing it to sit for 24-48 hours can help dissipate chlorine. For submersion, ensure at least one node on the stem, from which the aerial root emerges, is covered by water, as this is where new roots are most likely to form. Water temperature should ideally be between 65°F and 75°F (18°C to 24°C) for optimal root development.
Ongoing Care and Potential Issues
Maintaining aerial roots in water requires consistent attention. Regular water changes are necessary, ideally every few days or at least weekly, to replenish oxygen and remove accumulated impurities or bacterial buildup that could lead to root rot. Root rot is a concern, characterized by roots turning mushy, brown, or black, often with a foul odor, indicating a lack of oxygen. If signs of rot appear, immediately remove affected roots with clean, sharp scissors and replace the water.
Algae growth is another frequent issue, appearing as green slimy film on the container or roots. While generally not harmful, excessive algae can compete for oxygen and nutrients. Water contains limited nutrients, so for long-term submersion, diluted liquid fertilizer may be added, though it’s often unnecessary for short-term propagation. Roots in water thrive best in bright, indirect light and consistent room temperatures, avoiding direct sun exposure that can overheat the water.
Transitioning Aerial Roots to Soil
When aerial roots have sufficiently developed in water, typically 1-2 inches long with secondary roots branching off, they are ready for transition to soil. The process should be gradual to minimize shock. One method involves slowly introducing soil into the water container over several days or weeks, allowing roots to acclimate to a more solid medium.
For direct planting, prepare a well-draining potting mix appropriate for the plant type, often incorporating perlite or vermiculite for aeration. Gently transfer the plant from the water, carefully placing roots into a pre-moistened soil mixture in a pot with drainage holes. After planting, water thoroughly but avoid oversaturation, keeping the soil consistently moist for initial weeks to help water-adapted roots adjust. Positioning the newly potted plant in bright, indirect light and stable temperatures aids successful acclimation and reduces transplant shock.