Snake plant

Identification and origin

Dracaena trifasciata (family Asparagaceae) is the accepted botanical name. Molecular studies led botanists to fold Sansevieria into the genus Dracaena, but Sansevieria trifasciata remains a common synonym in the trade. The species is native to tropical Africa, from Nigeria and Cameroon to the Democratic Republic of the Congo and Tanzania, where it grows in rocky, dry habitats.

It is a stemless evergreen perennial that forms upright clumps. Its stiff, fleshy, flat, sharp-pointed leaves rise in a rosette from a thick rhizome. Up to 4 ft long and 2–4 in wide, they are cross-banded in dark green and gray-green, hence the name trifasciata (“three-banded”). Clumps reach 2–4 ft tall in the wild but seldom exceed 2 ft in a pot.

Mature plants may bloom in spring: small, tubular, greenish-white to cream flowers, sticky and fragrant (with hints of vanilla or jasmine), borne in racemes and followed by orange berries. Indoors this is rare and happens only on well-fed plants in very bright light.

Common cultivars include ‘Laurentii’, with golden-yellow margins; ‘Hahnii’, a dwarf “bird’s nest” rosette about 6 in tall, and its gold-edged form ‘Golden Hahnii’; ‘Moonshine’, pale silvery green; ‘Bantel’s Sensation’, striped with white; as well as ‘Black Gold’ and ‘Silver Queen’.

Light

It grows best in bright, filtered or indirect light and accepts a few hours of direct sun. Shield it from harsh midday sun in summer, which can scorch the leaves.

Its reputation as a shade plant needs a caveat: in a dark corner it survives on its reserves but barely grows and will not flower. Leaves stretch and variegation loses contrast; in sun the plant stays more compact. Avoid sudden changes: moved straight from a dark spot into full sun, it can burn. If you set it outdoors for the summer, give it a shady spot.

Watering

Overwatering is by far the leading cause of failure; its fleshy leaves let it go weeks, even months, without water.

Water according to the mix, not the calendar: push a finger into the pot and wait until it is dry deep down. Then water thoroughly, without pouring water into the center of the rosette, and empty the saucer.

How often depends on light, heat and pot. From fall to late winter, growth slows sharply: give just enough water to keep the leaves from puckering, unless the room is very warm. Wrinkled leaves signal real thirst; a mushy base signals too much water.

The dry air of most homes suits it: do not mist it, avoid steamy bathrooms and choose a well-ventilated spot away from cold air currents.

Potting mix

The mix must drain very freely: a peat-free cactus mix, or two parts loam-based potting mix to one part horticultural grit. All-purpose potting mix with about one third perlite or sand also works; the pH can be neutral to alkaline.

Always use a pot with drainage holes. Tall plants tip over easily: a heavy terracotta pot that is wider than it is tall keeps them steady, and its porous wall helps prevent overwatering.

Temperature

Ordinary indoor temperatures, around 59–75 °F, suit it, and it enjoys warmth. Kept dry, it tolerates cool spells near 50 °F, but it is best not to leave it below 55 °F for long. Keep it away from cold air currents and radiators.

It cannot take frost: it grows outdoors year-round only in USDA zones 10a–12b. In those climates its rhizomes spread, and in some regions it is rated a high invasion risk, so grow it in a container or an enclosed bed.

Repotting

Growth is slow and the plant likes to be pot-bound: repotting about every five years is often enough, every three years for dwarf forms such as ‘Hahnii’. In between, replace the top layer of mix each year.

Repot in spring, when roots and leaves fill or distort the pot; vigorous rhizomes can even crack terracotta. Choose a pot only slightly larger: excess mix stays wet and encourages rot.

In spring and summer, a liquid fertilizer at half strength about once a month is plenty; none in fall or winter.

Pruning

No pruning is needed. Cut damaged or mushy leaves at the base with sterilized tools, ideally in spring, removing no more than a quarter of the foliage at a time. Protect the leaf tips: a leaf with a broken tip may stop growing. Wear gloves, as the sap irritates skin.

Propagation

The easiest method is to separate the offsets that appear around the clump once they have roots and four or five leaves. When repotting in spring, you can also divide the clump into rhizome sections, each with leaves and roots; large divisions may need a stake at first.

For leaf cuttings, cut a mature leaf into sections 2–4 in long, let the cut ends callus for a day or two, then insert each section halfway into barely moist mix, keeping it the right way up (a notch at the top prevents mistakes). Keep them in a clear bag somewhere warm, ideally with bottom heat around 64 °F, in bright indirect light: new shoots appear in about two months.

Leaf cuttings from a variegated cultivar such as ‘Laurentii’ usually produce all-green plants; to keep the variegation, propagate by division or offsets.

Common problems

• Soft, brownish leaf bases with a rotten smell: rot from overwatering, especially in cool conditions; leaves yellow, then collapse.
• Leaves flopping or folding: too much water, too little light or very long drought. Collapse without overwatering can also come from vine weevil grubs feeding on the roots.
• Wrinkled leaves: prolonged lack of water.
• Long, pale leaves with dull variegation: not enough light.
• Brown or bleached patches: sunscald after a sudden change of exposure, or cold damage near a window in winter.
• Pests: mealybugs hiding at the leaf bases, and spider mites in hot, dry conditions.

A single symptom can have several causes: check watering, light, temperature and roots before acting.

Toxicity

All parts of the plant are toxic to dogs and cats (saponins): nausea, vomiting (sometimes with blood), diarrhea, lethargy, loss of appetite, excessive drooling, and dilated pupils in cats. It is also toxic to people if eaten, with low severity, and the sap irritates skin. Keep it out of reach of children and pets; if any part is swallowed, contact a veterinarian or Poison Control.