Aluminum Plant / Watermelon Pilea
Pilea cadierei makes a fantastic terrarium species thanks to its low growing habit, stunning foliage and easy care. Often called the aluminium plant for the beautiful silver variegation that’s splashed across the leaves, it’ll brighten up any terrarium project!
Native to China and Vietnam, this miniature Pilea is part actually part of the nettle family but grows more like a shrub. The characteristic silver splashes follow a regular raised pattern, with the longest streak radiating out from the base of the oval leaf, which then gives way to a series of smaller splashes.
With its shimmery foliage and low growing habit, it makes an attractive terrarium foreground plant to catch the eye.
At a Glance
Where to Buy Aluminum Plant
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Terrarium Plant Guide
Aluminum Plant Care & Growth
Try to place Pilea cadierei in a bright spot with lots of indirect light for best growth, but take care to keep out of direct sunlight to protect the delicate variegation.
This plant species has moderate water requirements and will fit well into most moist tropical terrarium conditions. As long as it has regular even moisture it’ll do just fine.
Pilea cadierei isn’t overly demanding in terms of substrate requirements, and should grow well in most tropical mixes that have adequate water retention and drainage.
Temperature & Humidity
This tropical species is sensitive to the cold, and should be grown in a terrarium that’s consistently above 15°C (60°F) to keep it healthy. Though, the aluminium plant is often grown as a houseplant – which would suggest it’s not too sensitive to humidity – it definitely grows well under high humidity conditions.
The shrub-like growth of Pilea cadierei tends to form compact clusters of plants with overlapping leaves. You can pinch the stems to promote this growth pattern if you want to keep them as short and bushy as possible.
This plant can occasionally bloom with some very muted green flowers, but you’d have a hard time spotting them amongst the foliage. You’re probably best pinching them off if you see them to keep the foliage bright and healthy.
Propagating the aluminium plant is pretty straightforward through stem cuttings. Simply take a cutting of a reasonable length just behind a node, remove the lower leaves if necessary to expose the stem, and then plant back into the substrate. It should readily root in a few weeks without any further intervention.
Varieties & Similar Plants
For miniature terrariums, the dwarf variety Pilea cadierei ‘Minima’ is an excellent choice. It’ll only reach about 6 inches tall even when fully mature, and the leaves are about half the size of those on Pilea cadierei.
Pilea cadierei has a somewhat finite lifespan of a few years, at which point it begins to deteriorate. Once it reaches maturity after a year or so, you can expect to see some leaf drop from the lower portions of the plant.
Growers often like to propagate and repot new plants every year or so to keep the foliage bright, but that can be needlessly challenging in a terrarium and I wouldn’t recommend it. Also, these can grow an extensive root system, so it’s not going to fit well into a project that’s looking to minimize the size of that layer.