Alocasia macrorrhizos ‘New Guinea Gold’

Where Alocasia ‘New Guinea Gold’ comes from

‘New Guinea Gold’ is a local form of Alocasia macrorrhizos from New Guinea. The wider species grows across the rainy tropics of the Malay Archipelago and western Pacific. Indoors, place it in bright indirect light and water regularly through the growing season. Its large roots need a deep, stable pot filled with a coarse mix.

Plant care for Alocasia macrorrhizos ‘New Guinea Gold’

• Light: Give it abundant filtered light or gentle morning sun after gradual acclimation. Protect the broad leaves from intense midday exposure.
• Watering: Keep moisture steady during active growth, watering when the upper few centimetres partly dry and the deeper root ball remains lightly moist. Check below the surface in a large container.
• Humidity: Aim for relative humidity around 60–80%.
• Airflow: Provide gentle air circulation around the large foliage and protect it from heated airflow and strong draughts.
• Temperature: Prioritise continuous warmth at about 22–30°C, including a warm root zone.
• Substrate: Use a rich, open mixture of coco fibre or peat, bark and pumice or perlite. It should retain useful moisture and allow immediate drainage and root aeration.
• Feeding: Apply a complete fertiliser at low to moderate strength during active leaf and root production. Reduce feeding when growth slows and flush the mix periodically.
• Basal growth: Retain healthy basal shoots, regardless of how much gold their current leaves show.
• Repotting: Use a heavy, stable pot, enlarge it gradually and keep the thick stem at its established depth.
• Propagation: Separate a well-rooted basal shoot or corm during warm active growth. Establish it in a modest draining pot with stable warmth and moisture.

Understanding changes in Alocasia macrorrhizos ‘New Guinea Gold’

• New growth appears greenYoung growth can be green, and the gold expression may disappear and return as part of this plant’s unusual colour cycle. Keep care stable and assess the plant by firmness, root health and continued growth. Light supports healthy growth; the gold cycle follows the plant’s own development.
• Green shoots arise from the baseThese shoots are healthy parts of the plant’s documented growth pattern and should remain attached. Removing or separating them as “reverted” growth can sacrifice viable plant material. Allow the full plant to continue through its green and gold phases.
• Gold leaves look like they are yellowingHealthy gold pigment can appear on petioles, leaves and even inflorescences, with firm tissue and active growth. A root problem is more likely when colour change is joined by limp leaves, a soft base, a wet root ball or roots that are dark and collapsing. Check the root system before changing feeding.
• The plant declines after a cold period‘New Guinea Gold’ performs best with stable warmth and can respond poorly to cool conditions. Move it away from cold glass and draughts, then check the root ball before watering. Remove limp, translucent or soft tissue once the boundary of the damage is clear.

Alocasia macrorrhizos ‘New Guinea Gold’ is toxic to people and pets

• Keep this plant away from children, cats and dogs.
• Its leaves and stems contain insoluble calcium oxalate crystals, which can irritate the mouth, throat, skin and eyes.
• Chewing may cause burning pain, drooling, swelling, vomiting or difficulty swallowing. Contact a veterinarian or medical professional after exposure, especially if swelling or breathing problems occur.

How ‘New Guinea Gold’ got its name

Alocasia combines the Greek prefix a-, meaning “without” or “lacking”, with Colocasia, the name of a related aroid genus.

The formal botanical citation is Alocasia (Schott) G.Don. George Don established the genus at that rank in 1839 in Hortus Britannicus, edition 3, page 631.

Macrorrhizos means “large-rooted”, from Greek makros, “large”, and rhiza, “root”. Carl Linnaeus described it as Arum macrorrhizon in 1753 in Species Plantarum, page 965. George Don transferred it to Alocasia macrorrhizos in 1839 in Hortus Britannicus, edition 3, page 631.

Trevor Ford collected ‘New Guinea Gold’ in November 1979 from the grounds of the Kavieng Hotel on New Ireland, Papua New Guinea; the plant was traced to a nearby village and taken to Australia.

Its New Guinea provenance and the gold colouring on its petioles and leaves account for the documented cultivar name.