Cereus repandus
| Light | Full sun to bright light; tolerates some shade but grows fastest in strong sun |
|---|---|
| Water | Moderate in warm growth, drying out between waterings; keep dry in winter |
| Soil | Free-draining gritty mix; tolerant of ordinary garden soil where drainage is good (see Soil and potting mix) |
| Temperature | Best above freezing; mature plants tolerate brief light frost. USDA zones 9–11 |
| Propagation | Cuttings (very easy) and seed |
| Toxicity | Non-toxic to cats and dogs; fruit is edible |
Cereus repandus is a large, fast-growing columnar cactus with a distinctly blue-green, waxy stem, widely grown as an ornamental landscape plant and for its sweet, edible fruit. Commonly known as the Peruvian apple cactus — a slightly misleading name, as the species is native to South America but not especially tied to Peru — it is one of the most forgiving and vigorous columnar cacti in cultivation, prized for its bold architectural form and rapid growth.
Description
Cereus repandus is a tree-like or shrubby cactus that can eventually reach several metres tall, branching from the base and higher up to form a candelabra of thick upright stems. The stems are stout and cylindrical, most often with a striking blue-grey to blue-green cast when young, maturing to a duller green with age. Each stem carries a small number of pronounced ribs — commonly around nine or ten — lined with areoles bearing short, variable spines; spininess ranges from nearly smooth to quite well armed between individual plants.
Large white flowers open at night, funnel-shaped and often 10 cm or more across, lasting only a single night before closing. They are followed by smooth, rounded fruits that ripen to red or yellowish tones. The fruit — sometimes sold as Peruvian apple — is fleshy, sweet and studded with small black seeds, edible and pleasant fresh.
A well-known monstrose form, often sold as Cereus repandus f. monstrose (the "monstrose apple cactus"), produces irregular, lumpy growth and is popular as an oddity in collections.
Distribution and habitat
The species is native to South America, occurring across parts of the Caribbean coast and the drier regions of Venezuela, Colombia and neighbouring areas, and it has naturalised widely in warm, arid parts of the world. It grows in hot, low-rainfall scrub and rocky ground, thriving on poor soils where drainage is sharp and sun is plentiful. Its toughness has made it a common sight as a hedge, boundary marker and dooryard fruit plant well beyond its native range.
Cultivation
Cereus repandus is among the easiest columnar cacti to grow, which accounts for its enormous popularity as a landscape plant and as rootstock. Give it full sun for the best colour and sturdiest growth, and a free-draining mix — though it is notably tolerant of ordinary garden soil where the ground does not stay wet. Water regularly through the warm growing season, allowing the soil to dry between waterings, then keep the plant dry through winter.
Growth is fast by cactus standards, and outdoor specimens in suitable climates can put on substantial height each year. In colder regions it is grown in containers and given a bright, frost-free winter rest; see Watering and Repotting for general technique. Mature plants tolerate brief light frost, but young growth and the blue waxy bloom are easily damaged by cold and harsh weather.
Because it is vigorous, cheap to raise and readily accepts scions, C. repandus is one of the standard rootstocks used by growers to speed up slow or delicate species. See Grafting for details.
Propagation
Propagation is very easy. Stem cuttings root readily: a length of stem is severed, allowed to callus for a week or two in a dry, shaded spot, then set on a gritty mix and kept barely moist until roots form. Seed is also straightforward, germinating quickly in warmth on a mineral surface — see Propagation — seed. The species' willingness to root from cuttings is a large part of why it has spread so widely as a hedge and fence plant.
Common problems
- Rot — the main risk, from waterlogged soil or cold, wet winters; stems soften and discolour, usually from the base.
- Cold and frost damage — young growth scars or collapses after hard frost; established plants are hardier than seedlings.
- Loss of blue colour — the attractive waxy bloom fades or rubs off with age, handling and weathering, leaving a plainer green stem.
- Pests — mealybugs in the areoles and scale insects on the stems are the usual offenders; watch for them in sheltered indoor plants.
See also
- Cereus — the genus overview
- Grafting · Soil and potting mix · Watering · Propagation — cuttings · Propagation — seed · Repotting