The Caterpillar Cactus

Appearance

• The caterpillar cactus grows to a maximum height of about 1 foot but, because it grows horizontally along the ground, it is usually much longer than it is tall. The cactus can grow up to 10 feet long -- a length that includes the living part only and not the dying, older portion. The plants bloom in the spring, but only at night, with white or yellow flowers. The caterpillar cactus has formidably sharp spines.

Environment

• Caterpillar cacti are found only in Baja California. They thrive in the region's cool, sandy soils. In optimum conditions, the plants can grow up to 2 feet per year, but growth greatly slows if the weather is too hot. Large, dense, overlapping clumps form where conditions are prime. Otherwise, the plant groups tend to be thinned out -- each individual stem being separated from the other.

Culture

• Stenocereus eruca grows best in full sunlight and in cool, moist, sandy soil. Well-draining soil is best, as overly saturated soil hastens the rotting of the stems. The caterpillar cactus thrives in consistently warm climates and are not tolerant of freezing temperatures. Indoors, you can grow them in commercial cactus potting soil; water them only from mid-spring to early fall.

The Spines

• Most cacti grow upright, which protects their flesh from the harsh, direct rays of afternoon sunlight. Just like any other plant, they can suffer from sun scald or overheating. Caterpillar cacti, on the other hand, creep along the ground -- exposing their stems to the sun. Fortunately, that flesh is protected by very wide, long, white spines, which thoroughly cover the plants and keep them from overheating.