How to Grow and Care for Alocasia Plumbea

The Alocasia plumbea, known as ‘Nigra’ or ‘Metallica’, is a dramatic plant from Southeast Asia. It is defined by large, arrow-shaped leaves with a metallic sheen. The foliage has a deep greenish-black surface, contrasting with its purple undersides, veins, and dark purple stems. As the plant matures, these characteristics become more pronounced, making it a sought-after specimen.

Alocasia Plumbea Care Instructions

Light

This plant thrives in bright, indirect sunlight, such as near an east-facing window or a few feet from a west-facing one. Direct sunlight will scorch the leaves and should be avoided.

Soil

Alocasia plumbea requires a loose, airy, and well-draining potting medium. An aroid-specific mix containing peat moss, perlite, and orchid bark is an excellent choice, as it ensures proper drainage and oxygen flow to the roots. A soil pH between 5.5 and 6.5 is beneficial.

Water

This plant is susceptible to root rot. Water thoroughly only when the top one to two inches of soil are dry. Allow water to flow through the drainage holes and discard any excess from the saucer to prevent the roots from sitting in water.

Temperature and Humidity

Alocasia plumbea prefers warm temperatures between 65°F and 85°F (18°C to 28°C) and high humidity. Keep it away from cold drafts and sudden temperature changes. To achieve the preferred 60% to 80% humidity, use a room humidifier or place the plant on a pebble tray.

Fertilizer

During the spring and summer, apply a balanced, water-soluble fertilizer every four to six weeks. Dilute the fertilizer to half-strength to prevent root burn. Suspend fertilization during the fall and winter when growth slows or stops.

Repotting

Repot this Alocasia every one to two years, or once it becomes root-bound. Spring is the best time for this task. Choose a new pot only one to two inches larger in diameter to avoid excess soil moisture.

Propagating Alocasia Plumbea

The most common way to propagate Alocasia plumbea is by dividing its corms during spring repotting. Carefully remove the plant from its pot and gently clear away soil to find the corms, which are small, firm bulblets attached to the root system, or look for distinct offshoots. Using a clean knife, separate these corms or offsets from the parent. Plant them in their own small pots with a well-draining mix. Keep the new plantings in a warm, humid location with bright, indirect light to encourage growth.

Common Problems and Solutions

Alocasias are susceptible to spider mites, which thrive in warm, dry conditions. Look for fine webbing on leaf undersides and a stippled appearance on the foliage. To manage them, wash the leaves with water and then treat the plant with horticultural soap or a neem oil solution.

Yellowing leaves often point to a watering issue, from either overwatering or underwatering. Assess the soil moisture and your routine to determine the cause. Drooping leaves can also signal underwatering, temperature stress, or transplant shock.

It is normal for this plant to enter dormancy during winter. It may stop producing new growth and can lose some or all of its leaves. This is a natural response, so significantly reduce watering until new growth appears in spring.

Toxicity Information

Handle Alocasia plumbea with care, as all parts are toxic to pets and humans if ingested. The plant’s tissues contain insoluble calcium oxalate crystals that cause immediate irritation to the mouth, tongue, and throat. Symptoms include oral pain, swelling, drooling, and vomiting. Position the plant out of reach of children and pets.