Plants

Trailing watermelon

Pellionia repens

BeginnerFine in a closed jar

Silver-marbled leaves on fast creeping stems. Cut it back in small jars.

What the simulation uses

Light: 1,000 to 8,000 lux; The brightness it grows well in.
Humidity: 60 to 95 % RH; Air moisture it is happy in; below the lower end it dries out.
Temperature: 16 to 27 °C; Comfortable range; outside it growth slows.
Dies at: below 10 or above 32 °C; Days beyond these temperatures kill it.
Soil pH: 5.5 to 7 pH; Soil acidity it prefers.
Grows up: 0.55 cm/month; How fast it gains height in good conditions.
Spreads: 3 cm/month; How fast its edge creeps outwards.
Copes with wet: fair; How well it stands soggy soil; poor means rot comes quickly.
Copes with still air: good; Sealed jars have still air; poor means grey mould finds it.
Copes with shade: good; How well it holds on in dim light.
Copes with drying: fair; How well it survives the jar drying out.
Water use: 0.08 ml/cm²/day; Water drawn up from its roots per cm² of leaves in room air; a sealed jar cuts this to a fraction and returns it down the glass.
Leaf drop: 3 %/month; Share of its leaves it sheds each month as litter for the cleanup crew.
Soft leaves: yes; Soft new growth that hungry isopods will nibble.
Full size: 7.5 cm tall, 45 cm wide; Its size when grown, before the lid stops it.

In shade and humid air it spreads quickly. A small jar fills up fast, so trim it back often. Cuttings are easy to tuck back in elsewhere.

Also called watermelon begonia, pellionia.

Estimated, where sources were thin: rates and limits are horticultural estimates, not measured.