Sansevieria masoniana
| Light | Bright indirect light to some direct sun; tolerates shade but grows slowly |
|---|---|
| Water | Sparingly; let the mix dry out fully between waterings, very little in winter |
| Soil | Gritty, free-draining mix (see Soil and potting mix) |
| Temperature | Warmth-loving; keep above about 10 °C, no frost |
| Propagation | Division of the rhizome; leaf cuttings (see notes) |
| Toxicity | Mildly toxic to cats and dogs if eaten |
Sansevieria masoniana, now properly placed in the genus Dracaena as Dracaena masoniana, is a bold, slow-growing succulent famous for its single enormous paddle-shaped leaf. That one leaf can reach the width of a spread hand and is mottled in bands of light and dark green, giving rise to the popular names whale fin and shark fin. It is one of the most collectible of the snake plants, grown as much for its sculptural presence as for its easygoing nature.
Description
Sansevieria masoniana is a rhizomatous, evergreen succulent that produces broad, upright, paddle- or fin-shaped leaves rather than the narrow upright blades of the more familiar snake plants. A well-grown leaf is strikingly wide, thick and stiff, with a subtly wavy margin often edged in a fine reddish-brown or purplish line. The surface is marbled with irregular light and dark green cross-banding.
The plant grows from a stout creeping rhizome, and its base is frequently tinged purple. Mature specimens may, in time, offset to form a small clump of these dramatic paddles, though the species is best known — and most prized — as a solitary single-leaf plant. Like other members of the group it can produce spikes of small, pale, fragrant flowers, but flowering is infrequent in cultivation and the plant is grown almost entirely for its foliage.
Distribution and habitat
The species originates in tropical Central Africa, in the region around the Congo — a heritage reflected in the old horticultural name Mason's Congo. There it grows in warm, seasonally dry conditions in dappled shade and open ground, rooted in loose, fast-draining soils. This background explains its tolerance of drought and warmth and its dislike of cold, wet roots.
Cultivation
Whale fin is an undemanding houseplant that rewards restraint. Grow it in a gritty, very free-draining mix in a pot only a little larger than the rootball, as it prefers to be somewhat snug. Bright indirect light brings out the best banding and keeps growth compact; it will take some direct sun and also survives in shade, though there it grows more slowly and can lose contrast in the markings.
Water only when the mix has dried out completely, then water thoroughly and let it dry again. In winter, when growth stops, keep it nearly dry and warm. The single biggest cause of failure is overwatering, which rots the rhizome and base — err on the side of neglect. Feed lightly during the growing season at most. Because the plant is slow and long-lived, Repotting is needed only every few years; see Watering for general technique.
Propagation
The most reliable method is division of the rhizome: an established plant that has produced a second paddle or an offset can be split, keeping a section of rhizome and roots with each leaf. This preserves the plant's character and gives an instant second specimen.
The species can also be grown from leaf cuttings — a large leaf cut into sections and rooted in a barely-moist gritty mix — but this is slow, and the resulting plantlets emerge from the rhizome that forms rather than from the cutting itself. Because a whale fin's appeal lies in a single large leaf, many growers prefer division to keep that form. See Propagation — cuttings and Propagation — offsets for details.
Common problems
- Rot — soft, browning or mushy tissue at the base is almost always overwatering or a poorly draining mix; reduce water and improve drainage.
- Toppling — a single tall leaf is top-heavy in a light pot; a heavier or snugger pot helps keep it upright.
- Pests — mealybugs (white fluff in the leaf base and folds) and occasionally spider mites are the usual culprits. See Pests and diseases.
- Cold damage — exposure to cold or frost causes translucent, collapsed patches; keep the plant warm.
See also
- Dracaena — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation — offsets · Propagation — cuttings · Pests and diseases