Spider plant

The spider plant came out of the coastal forests and grassland of southern Africa, where it grows in the leaf litter under trees and stores water in thick white roots for the dry months. That single fact explains most of its behaviour indoors. It wants the light that reaches a forest floor rather than the top of a canopy, it would far rather be forgotten for a fortnight than watered every other day, and it will keep going in conditions that kill fussier plants. It is the plant people are given, and the plant they keep for twenty years.

Light

Bright indirect light is where it looks best: a metre or two back from an east or west window, or beside a north window in the northern hemisphere and a south one in the southern. Direct midday sun through glass bleaches the leaves to a pale straw and scorches the edges. A dim corner is survivable, but the plant tells you it is unhappy in a particular way, by growing narrow leaves that lose their white stripe and drift back towards plain green. If that starts, move it before it goes further, because the variegation does not come back on leaves that already exist.

Water

Water when the top 2 to 3 cm of compost is dry, which in a warm room is roughly weekly in summer and every fortnight through winter. Water thoroughly until it runs from the drainage holes, then tip away whatever collects in the saucer. Those swollen white roots are a reservoir, so the plant handles a missed week without complaint and hates sitting wet. If the leaves go limp and the compost is damp, the problem is drowning, not thirst, and more water will finish it.

Tap water is the one real difficulty. Fluoride and chlorine accumulate in the tips of the leaves and burn them brown, and no amount of humidity fixes it. Rainwater, or tap water left standing overnight in an open jug, makes a visible difference within a couple of months of new growth.

Feeding and repotting

Feed monthly at half strength from spring to early autumn, and stop over winter. Restraint matters here more than with most houseplants: a well fed spider plant in a roomy pot puts everything into leaves and produces no runners at all, while one that is slightly potbound and moderately fed throws them by the dozen. If the plantlets are what you want, leave it a little tight.

Repot every second year, or when the roots start pushing the compost up out of the pot, which they will. Move up one size only, in spring, into ordinary potting compost with a handful of perlite. A pot two sizes up holds water the roots cannot reach and invites rot.

Pruning and propagation

Cut any browned or bent leaf right out at the base rather than trimming it halfway, and take off runners once you have taken what you want from them. Propagation is as easy as houseplants get. Sit a plantlet on a small pot of damp compost and hold it there with a bent paperclip while it is still attached to the parent, and it roots in two to three weeks; then cut the runner. Standing a detached plantlet in water works too, but roots grown in water are brittle and sulk for a fortnight after potting, so the pegged method is quicker in the end.

Ailments

Nearly everything that goes wrong with a spider plant is in the ledger below, and nearly all of it comes down to water: brown tips from what is in it, limp leaves and rot from too much of it, fungus gnats from compost that never dries. Faded stripes are a light problem, and the absence of runners is usually kindness rather than neglect.