How to Grow and Care for Purple Sword Plant

The Purple Sword Plant, Alocasia lauterbachiana, is a striking houseplant prized for its dramatic form. Native to the rainforests of Southeast Asia, its most notable features are the long, narrow leaves shaped like swords with scalloped edges. The tops of the leaves are a deep, glossy green, while the undersides present a contrasting deep purple or reddish-purple hue. This plant grows from a rhizome and can achieve a height of over a meter when mature.

Purple Sword Plant Care

Light

Proper lighting is a significant factor in the health of the Purple Sword Plant. It flourishes in bright, indirect light, which mimics the filtered sunlight of a tropical forest canopy. An ideal placement is near an east-facing window or a few feet from a south or west-facing window. Direct, harsh sunlight should be avoided, as it can scorch the delicate leaves and cause discoloration.

Soil

This plant requires a potting medium that is both well-draining and airy to prevent water from stagnating around its roots. A standard potting mix amended with perlite or orchid bark improves drainage and aeration. This type of mixture helps maintain the right level of moisture without becoming waterlogged.

Water

Water the Purple Sword Plant thoroughly when the top 1 to 2 inches of the soil feel dry to the touch. This practice helps prevent root rot, a common issue for overwatered Alocasias. Using filtered, distilled, or rainwater can prevent the leaf edges from browning, which can be caused by minerals in tap water. During winter dormancy, the plant’s water needs will decrease, so watering frequency should be reduced.

Temperature and Humidity

As a tropical native, the Purple Sword Plant prefers warm and humid conditions. The ideal temperature range is between 65-85°F (18-29°C), and it should be protected from cold drafts and sudden temperature drops. High humidity is beneficial, with levels of 60% or higher being optimal. To increase humidity, you can place the plant on a pebble tray filled with water, use a room humidifier, or group it with other plants.

Fertilizer

To support its growth, fertilizing is recommended during the spring and summer months. A balanced liquid fertilizer, diluted to half-strength, can be applied every four to six weeks. During the fall and winter, when the plant’s growth slows or it enters a dormant state, fertilizing should be paused.

Propagating Purple Sword Plant

New Purple Sword Plants are created through division, a process best performed in spring or early summer. Alocasias grow from rhizomes, which produce small offsets or ‘pups’ at the base of the mother plant. To begin, carefully remove the entire plant from its pot and gently loosen the soil to expose the rhizome. Identify any viable pups that have developed their own root systems.

Using a clean, sharp knife, cut the pup away from the main rhizome, ensuring the new division has both roots and at least one leaf. Once separated, pot the new division in its own container with fresh, well-draining soil. Keep the soil lightly moist as the new plant establishes itself. Placing it in a warm location with bright, indirect light will encourage new growth.

Common Problems and Solutions

Spider mites are a frequent pest for Alocasias, often identified by fine webbing on the undersides of leaves or small dots on the foliage. These can be managed by wiping the leaves with a damp cloth and treating the plant with neem oil or an insecticidal soap. Yellowing leaves are often a symptom of overwatering or poor drainage, so checking your watering schedule and soil composition is the first step. Brown, crispy edges on the leaves are typically caused by low humidity or underwatering. Drooping leaves can signal thirst, but might also indicate that the plant is entering a period of dormancy.

Is the Purple Sword Plant Toxic?

It is important for owners to know that the Purple Sword Plant is toxic to both pets and humans if ingested. The plant contains insoluble calcium oxalate crystals that can cause irritation. If a person or pet chews on or ingests any part of the plant, these crystals can lead to symptoms like oral pain, swelling of the mouth and throat, and drooling. To ensure safety, place the plant out of reach of curious pets and small children.