Alocasia 'Regal Shield' has very large, broad, deep green leaves with dark purple undersides that read as almost black in low light.
It is a hybrid of Alocasia odora and Alocasia reginae, and it inherited the size and speed of odora along with the darker colouring of reginae.
Light
Alocasia 'Regal Shield' grows best in bright, indirect light, with some tolerance for gentle morning sun.
Too little light
Stems stretch, new leaves come in smaller, and the purple undersides fade toward green.
Too much light
Hot afternoon sun bleaches the upper surface.
Watering
Water when the top 3-5cm (1-2 inches) of soil is dry. Large leaves mean heavy water use.
On average:
- Spring & summer: twice a week
- Autumn & winter: once a week
Signs of overwatering
- Leaves yellow from the oldest inward
- Stems soften at the base
- Soil stays wet for days
Signs of underwatering
- Leaves droop and stems bend over
- Leaf edges go crisp
Humidity and temperature
Humidity above 60% keeps the large leaves clean at the edges.
Keep it between 16°C and 29°C (61-84°F). It tolerates cooler rooms than the jewel Alocasia.
Soil and repotting
Soil
A rich but free-draining aroid mix. This hybrid is hungrier than the small Alocasia and takes more compost in the blend.
Repotting
Every spring while it is growing fast. Use a heavy pot.
Feeding
Balanced liquid fertiliser every 2 to 3 weeks through spring and summer. Nothing in autumn and winter.
Pruning and grooming
Remove leaves at the base once they yellow fully. Wipe the leaves occasionally, since they are large enough that dust makes a visible difference.
Dormancy
It can go dormant in a cold winter, though less readily than most Alocasia. Keep barely damp and warm until growth resumes.
Common problems
Fading purple undersides
Not enough light.
Drooping leaves
Usually thirst.
Yellowing lower leaves
Normal in small numbers, overwatering if several go at once.
Crispy edges
Humidity too low.