Alocasia plants, known for their striking, often arrow-shaped foliage, are a popular choice among plant enthusiasts. Propagating these plants can be a rewarding experience, and one natural and efficient method involves using their bulbils. These small, specialized structures offer a way to expand your collection or share these striking plants with others.
What Are Alocasia Bulbils?
Alocasia bulbils are small, rounded storage organs that serve as a means of vegetative reproduction. They appear as pea-sized, often brown or reddish structures resembling miniature corms, forming on the rhizomes or roots, usually underground. Their biological function is to store energy and nutrients, enabling the plant to survive adverse conditions and produce new growth. Bulbils are distinct from seeds (sexual reproduction) and stem cuttings, as they contain the genetic material to grow a clone of the parent plant. While sometimes referred to as corms, their primary role is vegetative propagation.
Harvesting Alocasia Bulbils
Harvesting bulbils from a mature Alocasia plant is best done during its active growing season, often undertaken during repotting to access the root ball where bulbils are found. Gently remove the plant from its pot and carefully shake off excess soil to expose the roots and any visible bulbils. Bulbils can be found attached to the plant’s roots or rhizomes, or sometimes loose in the soil. Use disinfected scissors or shears to snip the bulbil from the parent plant, avoiding damage to the bulbil or the main plant’s root system. Healthy bulbils should feel firm and plump; discard soft or squishy ones as they are likely rotted.
Propagating Alocasia Bulbils
Preparation
Once harvested, prepare Alocasia bulbils for sprouting. You may gently peel the outer brown shell to reveal a creamy white core, but this step is not always necessary. After cleaning, you can soak bulbils in water for a few hours.
Medium Selection
Selecting the right growing medium is important for successful propagation. Pre-moistened sphagnum moss, perlite, or a mix of soil with perlite and sand for good drainage are popular choices. Place the bulbil with its pointed end facing upwards, burying it just beneath the surface or partially covering it with the chosen medium. Other methods include placing bulbils in LECA (Lightweight Expanded Clay Aggregate) or directly in water, ensuring the water level does not completely submerge the bulbil to prevent rot.
Optimal Environment
Creating an optimal environment for sprouting involves high humidity and consistent warmth. Many propagators use a clear plastic container, a small terrarium, or a plastic bag over the pot to create a miniature greenhouse effect, which traps humidity around the bulbils. Maintain temperatures between 60 to 85 degrees Fahrenheit (15.6-29.4°C). Ensure the medium remains consistently moist but not waterlogged, which can lead to rot. Sprouting can take several weeks, with roots often appearing first, followed by a small leaf.
Caring for New Bulbil Plants
Light Requirements
Once Alocasia bulbils have sprouted and developed a small leaf or two, their care transitions to nurturing these young plants. They require bright, indirect light, avoiding direct sunlight which can scorch leaves. An east or west-facing window is suitable, or a location with diffused light. Supplemental grow lights can provide the necessary intensity.
Watering
Watering should be consistent, keeping the potting medium evenly moist but not soggy. Allow the top inch or two of the soil to dry slightly before watering again to prevent root rot.
Humidity and Transplanting
High humidity remains important for these young plants, which can be maintained with a humidifier, pebble tray, or by grouping plants together. When true leaves are established and roots are visible, transition the young plant from the propagation medium to a well-draining potting mix. Fertilization should be delayed for at least a few months after transplanting, and then applied sparingly with a diluted liquid houseplant fertilizer during the growing season.
Troubleshooting Bulbil Propagation
Failure to Sprout
Bulbils may fail to sprout due to insufficient warmth or humidity. Ensuring a consistent temperature range of 60-85°F (15.6-29.4°C) and maintaining high humidity levels encourages activity. If bulbils are soft or squishy upon harvesting, they are likely rotted and will not sprout.
Rot and Slow Growth
Rot is a frequent concern, caused by overwatering or poor air circulation. The propagation medium should be moist but never waterlogged; periodic aeration helps prevent fungal issues. Slow growth indicates conditions are not ideal; adjusting light, temperature, and humidity can accelerate development. If a bulbil appears to be struggling, inspect it for signs of rot and adjust moisture levels.