Say it: SEER-ee-us peh-roo-vee-AH-nus / FORBZ-ee-eye. Common names: Peruvian apple cactus, hedge cactus, night-blooming cereus; monstrose forbesii is sold as 'Ming Thing'.
Where it grows
Despite the name, Cereus peruvianus (also listed as C. repandus or C. hildmannianus) is from eastern South America: Brazil, Uruguay and Argentina. Cereus forbesii comes from Argentina, Bolivia and Paraguay.
Size and growth
Tall, blue-green columns with 6–9 ribs, branching into tree-like plants 20–30 feet tall. One of the fastest cacti: a seedling can be several feet tall in 5 years in the ground. The monstrose forbesii grows as a mass of knobby, lumpy stems with few spines, usually staying under 3 feet — a sculptural plant that looks different from every angle.
Flowers and fruit
Big white flowers, 6 inches across, open at night in summer and close by morning. Peruvianus follows with smooth red fruit (pitaya) that tastes like a mild dragon fruit — it's farmed commercially for them.
Care
- Light: full sun.
- Water: regular in summer, dry in winter. Tolerates more water than most cacti.
- Soil: any fast-draining mix.
- Cold: hardy to around 25°F for short periods.
From seed
Easy and fast, germinating in 7–14 days. Seed from monstrose forbesii gives a good share of monstrose seedlings along with some normal ones; the lumpy growth usually shows within the first year.