The Alocasia amazonica ‘Polly’, commonly known as the Purple Sword Plant, is a captivating houseplant cherished for its striking foliage. Its dark green, arrow-shaped leaves feature prominent silver-green veins and distinctive purple undersides, adding an exotic touch to any indoor space.
Essential Care Requirements
Light
The Purple Sword Plant thrives in bright, indirect light conditions. Placing it near an east-facing window or in a spot with filtered sunlight is ideal. Direct sunlight should be avoided as it can scorch the delicate leaves, leading to discoloration. Conversely, insufficient light can result in stunted growth and less vibrant leaf coloration.
Watering
The Purple Sword Plant requires consistent moisture, but avoid soggy soil. Allow the top inch or two (2.5-5 cm) of soil to dry before watering. Overwatering causes root rot, while underwatering can lead to dormancy or drooping leaves. Reduce watering frequency during winter when growth slows.
Soil
A well-draining, aerated potting mix rich in organic matter is ideal for Alocasia ‘Polly’. A suitable blend combines equal parts peat moss, perlite, and potting soil. Incorporating orchid bark or coco coir enhances drainage and aeration. Ensure the pot has drainage holes to allow excess water to escape.
Temperature and Humidity
The Purple Sword Plant, originating from tropical regions, prefers warm temperatures between 65-80°F (18-27°C). Temperatures below 65°F can cause dormancy or damage. High humidity, 60% or more, is also beneficial. Increase humidity by grouping plants, using a pebble tray, or employing a humidifier.
Fertilizing
During the active growing season, feed your Purple Sword Plant with a balanced liquid fertilizer. Dilute the fertilizer to half strength and apply every two to four weeks. Reduce or stop fertilizing during fall and winter when growth slows. This prevents salt buildup, which can harm the plant.
Repotting and Potting Tips
Repotting is needed every one to two years, or when the plant becomes root-bound, indicated by roots growing out of drainage holes. The best time to repot is during spring, as the plant enters its active growth phase. Choose a new pot only one size larger than the current one to prevent excessive moisture retention.
When repotting, gently remove the plant and loosen any circling roots. Place it in the new pot with fresh, well-draining soil mix, ensuring the plant is at the same depth. Water thoroughly after repotting to help the new soil settle. Plastic or glazed ceramic pots help maintain soil moisture more effectively than porous materials like terracotta.
Propagating Your Purple Sword Plant
The primary method for propagating the Purple Sword Plant is through the division of its rhizomes or corms. This process is best performed during repotting, when the plant is already out of its pot. Carefully remove the plant and gently shake off excess soil to expose the root system and any small, dormant bulblets (corms).
Gently separate rhizome clumps or individual corms, ensuring each section has roots attached. Avoid unnecessary cutting or breaking of the main rhizome. Plant each separated division in its own pot with fresh, well-draining potting mix. Keep newly potted divisions in a warm spot with bright, indirect light and maintain consistent moisture to encourage establishment.
Common Issues and Troubleshooting
Yellowing leaves
Yellowing leaves signal issues with watering or light. Overwatering is a primary cause, leading to soggy soil and root rot, but underwatering can also cause yellowing. Insufficient light can also result in yellowing, particularly on older leaves. Adjusting watering and ensuring adequate bright, indirect light can help.
Brown leaf tips or edges
Brown leaf tips or edges sign low humidity or inconsistent watering. The plant’s tropical origin means it thrives in high humidity, and dry air can cause leaf margins to crisp. Ensuring consistent moisture and increasing ambient humidity can alleviate this. Over-fertilization also contributes to brown tips due to salt buildup; periodic soil flushing with plain water helps.
Drooping leaves
Drooping leaves indicate various stressors, including overwatering, underwatering, or temperature fluctuations. When the soil is too dry, the plant may droop from thirst, while overly wet conditions also cause a similar response due to root stress. Extreme temperatures or cold drafts also lead to wilting foliage. Ensuring proper watering, a well-draining pot, and stable temperatures will help restore turgidity.
Pests
Purple Sword Plants are susceptible to common houseplant pests such as spider mites, mealybugs, and aphids. Regularly inspecting foliage, especially the undersides of leaves, can help detect infestations early. If pests are found, they can often be treated with organic solutions like neem oil or insecticidal soap. Maintaining appropriate humidity also deters spider mites, which prefer drier conditions.