Dumb cane

Dumb cane comes from the forests of the Caribbean and tropical South America, where it grows in shade as a thick stemmed herb with very large marked leaves. It is a good plant for an average room, tolerant of medium light and irregular attention, and it grows quickly enough to be satisfying. It also has the most unpleasant sap of any common houseplant, and the entire reason it carries the name it does is that chewing a leaf swells the tongue enough to stop a person from speaking. Both of those things are true at once, and both are worth knowing before you choose where to put it.

Light

Medium indirect light suits it. It tolerates a dimmer position than most plants with leaves this size, which is why it works in an interior room, but the cream and white markings fade towards green in real gloom.

Direct sun through glass is too much and scorches the leaves in an afternoon. A spot a couple of metres from a bright window, or beside a shaded one, is right.

Water

Water when the top 3 cm of compost is dry, roughly weekly in summer and every fortnight in winter, and let it drain. It wants to be lightly moist rather than wet, and it responds to a pot that has dried out completely by dropping its lower leaves.

Cold wet compost in winter is what kills it. If the room is cool, water less rather than on the same schedule, and make sure the pot is not standing in a saucer.

Warmth and humidity

Keep it above about 16 degrees and out of draughts. Average room humidity is acceptable, though the leaf edges stay better in a room that is not bone dry, and grouping it with other plants or standing it on a tray of wet pebbles both help.

Feeding and repotting

Feed at half strength monthly from spring to early autumn and stop in winter. Repot in spring when roots fill the pot, and choose a heavy pot for a tall plant, because a dumb cane becomes noticeably top heavy as its cane lengthens.

Pruning, propagation and gloves

A dumb cane grows into a bare cane with a head of leaves, and the cure is to cut it. In spring, cut the stem straight across at the height you want with clean secateurs. The stump shoots from below the cut within a couple of months, usually producing two or three stems where there was one, which is how a leggy plant becomes a full one.

Nothing is wasted. The leafy top roots as a cutting in damp compost. The bare middle can be cut into sections, each with at least one node, laid on their sides on damp compost and half buried, where they sprout in warmth.

Wear gloves for all of it, and keep the sap away from your eyes and mouth. It is a genuine irritant, not a theoretical one, and washing your hands afterwards is not optional.

Where to put it

This is the plant on the list where placement is a safety decision rather than an aesthetic one. The sap is irritant enough that a chewed leaf causes real pain and swelling, and the leaves sit at exactly the height a toddler or a dog will meet them. On a high shelf, on a plant stand, or in a room that a small child and an animal do not use unsupervised, it is a fine houseplant. On the floor of a family living room it is a poor choice, and a Chinese evergreen gives a similar look with a milder sap.

Ailments

A slow steady loss of the lowest leaves is the plant building its cane. Several at once with damp compost is overwatering. A long bare stem is a light problem with a pruning answer. Brown crisp edges are dry air. A soft base is rot and means saving the top. The ledger below has the rest.