Alocasia zebrina is part of the Araceae family and is native to the Philippines.
‘Black Stem’ is a cultivar, it has sagittate leaves which sit upon deep red (almost black) petioles. Each new leaf emerges from a sheath on the side of the petiole, this is known as a petiolar sheath.
Genus name comes from the Greek ‘a’ meaning without and ‘locasia’ meaning lotus root. The specific epithet comes from the Latin meaning stripes like a zebra.
Light: Alocasia zebrina 'Black Stem' thrives in bright, indirect light. Strong, direct sunlight can harm its leaves, potentially causing scorching. Insufficient light may result in slower growth and less prominent stripes. A spot near a window with filtered light in a typical UK home is ideal.
Water: The potting mix should be kept consistently damp but not saturated. Allow the upper inch or two of the soil to dry between waterings. Ensure the pot drains exceptionally well to prevent root problems, which can be an issue, especially in the UK’s climate. Reduce watering in autumn and winter when the plant's growth naturally slows or it enters dormancy.
Soil: An airy potting mix that drains well is essential. A mix specifically created for aroids, incorporating materials such as coco coir, perlite, and orchid bark, is often recommended to provide the necessary air circulation and drainage.
Fertilising: Use a diluted liquid fertiliser every two to four weeks during the active growing period in spring and summer. Reduce or stop fertilising during the autumn and winter months.
Temperature: This plant prefers warm temperatures, ideally between 18°C and 27°C. It should be shielded from cold draughts and sudden temperature changes, which can occur indoors, particularly during colder UK months. Temperatures below 15°C (59°F) may trigger dormancy.
Humidity: Higher humidity levels are highly beneficial for Alocasia zebrina 'Black Stem', ideally above 60%. Consider using a humidifier or placing the plant on a pebble tray with water to maintain optimal conditions, especially during drier indoor periods.
Growth Habit: This Alocasia has an upright, clumping growth habit, with new leaves emerging from a central rhizome. It can grow to a significant size indoors, making it a prominent feature.
Toxicity: Like all Alocasias, this plant is toxic if consumed by humans or pets.