Euphorbia lactea
| Light | Bright light to some direct sun; the white 'White Ghost' form needs shade from harsh sun |
|---|---|
| Water | Moderately in growth; let the soil dry out between waterings; keep nearly dry in winter |
| Soil | Fast-draining gritty mix (see Soil and potting mix) |
| Temperature | Keep above about 10 °C; USDA zones 10–11 |
| Propagation | Stem cuttings (allow the cut to callus first); grafting for crested and coloured forms |
| Toxicity | Toxic; the milky latex is irritating to skin, eyes and if swallowed — keep away from pets and children |
Euphorbia lactea is an upright, branching succulent from tropical Asia — most likely native to India — that grows into a candelabra of narrow, three- or four-angled green stems. Widely cultivated across the tropics, it is best known to hobbyists through its ornamental selections: the ghostly white-variegated White Ghost, and the crested and often gaudily coloured coral or crest novelties sold grafted onto a green rootstock. Despite its ribbed, cactus-like look and the common name candelabra cactus, it is a true Euphorbia and not a cactus at all. It is also known as mottled spurge.
Description
Euphorbia lactea forms erect, sparingly branched stems that in age build a shrubby candelabra to a metre or more tall. Each stem is slender and sharply three- or four-angled, the ribs edged with short paired spines and typically marbled down the centre with a paler grey-green zone — the "mottling" behind the name mottled spurge. Like all euphorbias it lacks true areoles, and its structural resemblance to a cactus is a case of convergent evolution rather than kinship.
The plant carries only tiny, short-lived leaves along the young rib margins. It flowers rarely in cultivation; the true flowers are the reduced cyathia typical of the genus rather than showy blooms. Every part of the plant exudes a copious white latex when cut.
Distribution and habitat
The species is generally regarded as native to India and adjacent tropical Asia, though centuries of cultivation have blurred its exact wild range. It has become widely naturalised throughout the tropics, where it is grown as a living fence and hedge plant. It favours warm, frost-free conditions and open, well-drained ground in full sun.
Cultivation
Euphorbia lactea is an easy, fast, tolerant plant given warmth and drainage. Grow it in a gritty, free-draining mix and water moderately through the warm months, letting the medium dry between waterings; reduce watering sharply in winter and keep it above roughly 10 °C. The plain green form takes bright light and some direct sun happily, while the white-variegated 'White Ghost', having little chlorophyll, scorches easily and prefers bright shade.
The most important cultivation note is safety. Cut or broken stems bleed an irritant white latex that can inflame skin and eyes and is dangerous if it reaches the mouth — wear gloves and eye protection when pruning, wash off any sap promptly, and keep the plant out of reach of pets and children. See Watering and Repotting for general technique.
Propagation
The green form roots readily from stem cuttings. Take a length of stem, rinse or blot away the bleeding latex, and let the cut end callus and dry for several days to a week before setting it in a dry, gritty mix to root — plant material set in too early tends to rot. Handle cuttings with the same care as pruning, given the caustic sap. See Propagation — cuttings for a full walkthrough.
Variegated and crested selections are usually not grown on their own roots but propagated vegetatively and maintained by grafting (see below).
Cultivars
Two ornamental groups dominate the hobby:
- White Ghost — a near-white variegated form in which most of the chlorophyll is lost, giving ghostly pale stems. Because it photosynthesises poorly, it grows slowly, needs protection from strong sun, and is less cold- and stress-tolerant than the green plant.
- Crested / "coral" forms (Euphorbia lactea f. cristata) — plants whose growing point has fasciated into a wavy, brain- or coral-like fan. These crests are frequently sold grafted onto a straight green Euphorbia rootstock (often plain E. lactea or a related species) for vigour and display, and brightly pigmented pink, yellow and cream "coral" selections are popular novelties. Grafted specimens depend on the health of their rootstock and appreciate warmth and good light.
Common problems
- Rot — from overwatering, a soggy mix, or rooting fresh cuttings before they have callused; stems soften, discolour and collapse.
- Sun scorch — especially on 'White Ghost' and pale crests, whose reduced chlorophyll leaves them prone to bleaching and burning in strong direct sun.
- Latex irritation — not a plant ailment but a grower hazard: the sap can cause painful skin and eye irritation, so treat every cut with respect.
- Pests — mealybugs (white fluff in the rib grooves) and scale are the usual offenders; see Pests and diseases.
See also
- Euphorbia — the genus overview
- Grafting · Soil and potting mix · Watering · Propagation — cuttings · Repotting · Pests and diseases