Alocasia ‘Sumo’

Parentage and origin of Alocasia ‘Sumo’

Alocasia ‘Sumo’ is a hybrid of Alocasia ‘Portora’ and Alocasia princeps. ‘Portora’ is a hybrid of Alocasia odora, which grows in Asian rainforest, bamboo thickets and riverbanks, and Alocasia portei from secondary forest on Luzon. A. princeps grows on well-drained Bornean forest slopes and ridges.

Growing Alocasia ‘Sumo’

• Space: Plan for a broad, substantial plant. Give the leaves room to spread and use a heavy, stable pot as the plant gains size.
• Watering: Water as the surface begins to dry, keeping the deeper root zone lightly moist and never leaving the pot standing in runoff.
• Light: Bright, diffuse daylight suits its large foliage; introduce direct sun only gradually.
• Potting mix: For this large plant, choose a loose, fertile mix that holds some moisture without becoming heavy.
• Humidity: Conditions around 60–80% are suitable. Let a small amount of air move through the foliage. A bright, sheltered position suits it; keep the leaves clear of heater and air-conditioning airflow.
• Temperature: Keep conditions around 18–29 °C, keeping it clear of prolonged chilling below 15 °C.
• Feeding: During active clump growth, apply complete houseplant fertiliser at moderate strength. Once growth slows, lengthen the interval between feedings.
• Repotting: Move up one pot size when the root system is crowded and needs more room.
• Propagation method: A rooted offset or firm corm can be separated from the parent plant and established in its own warm pot.

Yellowing lower leaves, fine speckles and scorched margins

• Lower foliage starts to sag and yellow while the mix is still moist: Size alone is not a reason to water again. Let the pot dry further, and check the roots if more leaves begin to fail or the base loses firmness. Use our root-rot guide if you uncover decay.
• Fine pale speckles or bronze colouring spread across the dark leaves: Turn the affected leaves over and inspect the areas beside the main veins for spider mites. Grey tones and purple veins are normal on ‘Sumo’; new pale speckles, fine webbing or moving mites are not. Separate the plant from nearby plants and use a treatment labelled for spider mites on indoor ornamental plants, repeating it according to the label. Our spider-mite guide covers treatment and follow-up.
• A broad leaf develops pale tan or brown areas after brighter sun reaches it: Sudden direct exposure can scorch ‘Sumo’. Pull it back from harsh midday light and increase brightness in smaller steps. The marked tissue will remain visible.
• The broad leaf margins become dry and crisp: Look for a sharp dry-out, hot air from heating or a strong draught. Large leaves can lose moisture quickly, but keeping the potting mix permanently wet is not the answer. Return to a steadier watering rhythm and a less drying position.

Alocasia ‘Sumo’: 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.

Names in the parentage of Alocasia ‘Sumo’

Portora blends portei, which honours Marius Porte, with odora, meaning “fragrant”. The other parent name, princeps, means “chief” or “foremost”.