Alocasia ‘Sedenii’

Parentage and origin of Alocasia ‘Sedenii’

The cross behind ‘Sedenii’ brings together Alocasia cuprea and Alocasia longiloba ‘Lowii’. A. cuprea grows on rocky Bornean rainforest slopes. A. longiloba occupies humid Southeast Asian forest floors, ravines and pockets of soil among boulders.

Both parent species come from humid habitats with quick drainage.

Care for Alocasia ‘Sedenii’

• Watering: During active growth, water again as the upper part of the mix begins to dry; do not wait until the potting mix is dry all the way through. Water until excess runs from the drainage holes. Let the pot drain, then empty any water left in the saucer or cover pot.
• Light: Give ‘Sedenii’ a bright, softly lit position and avoid long periods of harsh sun.
• Potting mix: Choose a loose, fertile mix that drains promptly after a thorough watering.
• Temperature: Keep it around 18–29 °C and away from cold windows or draughts. Move it away from cooler spots before temperatures fall below 15 °C.
• Humidity: Alocasia does best with medium to high humidity. Keep it in a bright spot away from heaters and air-conditioning. If the air is dry, place it near other houseplants that like similar conditions, leaving space between the leaves, or use a clean humidifier.

Signs of trouble on Alocasia ‘Sedenii’

• Fresh growth develops scraped silver marks with tiny black specks: The metallic blue-green sheen of ‘Sedenii’ can look different as the light changes, but the leaf surface itself should stay smooth. Fresh scraped-looking marks with black specks point instead to thrips feeding on young growth. Check the folded leaves and, if you find thrips, isolate the plant and use a treatment labelled for thrips on indoor ornamental plants, repeating it according to the label.
• Fine pale speckles or webbing spread across the metallic leaves: Turn the leaves over and look closely around the main veins. A changing sheen is normal; moving spider mites or fine webbing are not. Isolate the plant and use a treatment labelled for spider mites on indoor ornamental plants, repeating it according to the label. See our spider-mite guide for follow-up checks.
• The whole plant droops and the leaf stalks start losing firmness: Check whether the potting mix is very dry or has been staying wet for too long. A dry plant needs a thorough watering. If the pot is still wet and the plant feels soft around the base, inspect the roots for rot instead. The root-rot guide explains what to do if you find decay.
• The leaf margins become dry and brown: Think about whether the plant has dried out sharply, been exposed to hot or cold draughts, received strong direct light or had too much fertiliser. Deal with whichever fits the recent conditions rather than automatically watering more.

Alocasia ‘Sedenii’: toxic if chewed

• Pets: This Alocasia is toxic to cats and dogs. Keep the plant and any cut pieces where pets cannot chew them.
• Children and handling: Keep it out of reach of children. Sap from damaged tissue can irritate skin and eyes, so wash your hands after pruning and avoid touching your face.
• Why it irritates: Alocasia tissue contains insoluble calcium oxalate crystals. Chewing or contact with sensitive tissue can cause immediate local irritation.
• Possible symptoms: Mouth exposure can cause burning pain, drooling, swelling, nausea or vomiting, and difficulty swallowing.
• After exposure: For a pet, contact a veterinarian. For a person, remove any plant material from the mouth and rinse with water; seek medical or poison-control advice if symptoms are significant. Breathing difficulty or rapidly increasing swelling needs urgent medical attention.

Who Sedenii honours

Sedenii honours nineteenth-century Veitch hybridizer John Seden.

The artificial hybrid Alocasia × sedenii Veitch was published in Gardeners’ Chronicle in 1869. The hybrid formula is Alocasia cuprea × Alocasia longiloba.