ZZ plant

The ZZ plant grows wild in the grassland and dry forest of eastern Africa, from Kenya down to South Africa, in places that flood in a wet season and then stay bone dry for months. It survives that by storing water in fat underground rhizomes that look more like potatoes than roots, and by holding a thick waxy skin over every leaflet so that almost nothing evaporates. Brought indoors, it behaves exactly as that history suggests. It is the plant that lives in the hotel lobby with no window, the office nobody waters, and the flat that stands empty for a month, and it comes through all three.

Light

It genuinely tolerates low light. Not the marketing sense of low light, which usually means a bright room away from the window, but the real thing: a room lit by a north window in the northern hemisphere, or by nothing but lamps. It will not grow quickly there, perhaps two new stems a year rather than five, but it holds its colour and does not thin out.

Bright indirect light is where it does best, and the difference is obvious within a season. What it will not take is direct sun through glass, which bleaches the gloss off the leaflets and leaves dry brown patches that never green up again.

Water

Water only when the compost is dry all the way through, which in a warm room means about two to three weeks in summer and five in winter. Push a finger deep into the pot or, better, lift it: a plant that needs water is noticeably light. When you do water, soak it properly until it runs from the drainage holes, and empty the saucer.

If you are unsure, wait. This is one of the few houseplants where doing nothing is nearly always the safer choice. The rhizomes carry weeks of reserve, and the single thing that kills a ZZ plant is compost that stays damp around them. Yellowing lower leaves are the first sign, and by then the rot is usually already under way.

Feeding and repotting

Feed at half strength two or three times between spring and late summer, and not at all in winter. The plant grows so slowly that a full strength monthly feed simply builds up salts in the compost.

Repot every third year, or when the rhizomes are visibly lifting the surface or bowing the sides of the pot, which they will do eventually. Go up one size only. A snug pot dries out properly between waterings, and that is a large part of why the plant survives so much neglect. Use a free draining compost with a third perlite or fine bark mixed through.

Pruning and propagation

Cut any yellow or damaged stem right out at soil level rather than trimming the leaflets. Wipe the leaves occasionally with a damp cloth; the shine is the plant’s own and dust dulls it quickly.

Division is the quick way to propagate. At repotting, pull the clump apart so each piece keeps at least one stem and one plump rhizome, and pot the pieces separately. Leaf cuttings work too and are a lesson in patience: push a leaflet base first into damp gritty mix, keep it barely moist, and wait. A small rhizome forms in anything from two to nine months, and the first stem appears well after that.

Ailments

Yellow lower leaves, a soft base and a sour smell from the compost are all the same problem seen at different stages, and the answer to all three is less water and a look at the rhizomes. Stretched pale stems are a light problem. Brown crisp patches are sunburn or a radiator. Everything else is in the ledger below, and there is not much of it, because a plant this slow rarely has time to go wrong.