Ponytail palm

Identification and origin

Beaucarnea recurvata belongs to the asparagus family, Asparagaceae; despite appearances, it is not a true palm. It is also known by the synonym Nolina recurvata. It is native to eastern Mexico (Tamaulipas, San Luis Potosí, Veracruz, Puebla and Oaxaca), where it grows on rocky, poor soils in low deciduous forest and semi-arid country. In the wild, the species is critically endangered by habitat destruction and collecting.

Its outline is unmistakable: a caudex, a hugely swollen base shaped like a bottle or an elephant’s foot, with gray bark that cracks with age, serves as a water reserve. It carries a single stem when young, which may branch over the years. At the top, rosettes of narrow, flat, leathery, dark green leaves with finely toothed edges cascade like a fountain; on old plants they reach 6 ft long and barely 1 in wide. In the wild it can reach 29.5 ft or more; in a pot it grows slowly and eventually reaches 6–8 ft. Only old specimens bloom, with panicles of tiny creamy white flowers; plants are either male or female, and flowering indoors is very rare.

Light

Give it as much light as possible: full sun suits it. Indoors, a south-facing window with direct sun is ideal; it can adapt to a very bright room or an east- or west-facing window. Turn the pot every week so it grows straight. It can spend the summer outdoors once spring frosts are over, as long as you acclimate it gradually to full sun and cooler nights.

Watering

Water deeply but infrequently: moisten all of the mix, let it drain completely, then wait until it is nearly dry before watering again. Use tepid water, ideally in the morning. Overwatering is the most common cause of failure: the caudex lets the plant ride out drought, not constant wet. From fall through winter, cut back sharply without letting the roots dry out completely. It prefers dry air, so there is no need to mist it. Outdoors in summer it drinks more, but it should still dry out between waterings.

Potting mix

It needs a gritty, very fast-draining mix, such as a cactus mix. You can also combine three parts fine grit or coarse sand with one part potting soil and a little coir or shredded bark. Choose a fairly small pot with drainage holes, set on a separate saucer that you empty after each watering. In spring and summer only, a light feeding with cactus or houseplant fertilizer about every other month is plenty; avoid overdoing it.

Temperature

It likes warm, dry conditions, ideally 64–75 °F, away from air currents from doors, vents and windows. It handles high heat very well and winters easily in a heated room; it is easiest to grow when temperatures stay fairly steady. Cold is its weak point: do not let it drop below 50 °F, because temperatures near that mark can already kill it. Bring it in before the first cold spells of fall. It can only be grown outdoors year-round in USDA zones 10a to 11b.

Repotting

It can stay in the same pot for many years and likes being snug. Repot in spring, about every two years, only when the swollen base reaches the edge of the pot, and go up just one pot size: an oversized pot stays wet and encourages rot. Never bury the stem deeper than it was. Keep in mind that a bigger pot lets it gain height and girth, while a small pot slows its growth.

Pruning

It needs no regular pruning. Remove old, dry leaves and trim brown tips with clean scissors. The small offsets that sometimes appear on the caudex can be removed to keep a single trunk, or left to grow. If the plant gets too tall, you can shorten the stem in spring, as growth resumes, with a sterilized tool; keep the wound dry afterward to avoid infection. A young stem that is cut or broken will often branch.

Propagation

It is propagated mainly from seed, although seed is rarely available. Sow in spring at 68 °F or warmer: the seeds germinate readily with no special treatment, and growth afterward is slow. Offsets at the base can be removed with a clean tool, left to callus for several days, dusted at the base with rooting hormone and potted in a gritty mix kept barely moist; even so, they do not root reliably.

Common problems

The same symptom can have several causes: check watering, light and temperature before acting.

• Dry brown leaf tips: very common indoors; uneven watering (too much or too little), low light, unsuitable temperatures or fertilizer salt buildup. The dead parts can be trimmed off.
• Wrinkled, soft base: a sign of bacterial or fungal rot in the caudex, caused by overwatering or poor drainage.
• Root and stem rot: in soggy soil; it can kill the plant.
• Old leaves turning brown: natural if only a few of the lowest leaves are affected.
• Pests: spider mites, mealybugs and scale; chewing insects can also disfigure the leaves.
• Diseases: leaf spots and bacterial leaf streak.
• Dust: it builds up easily on the long leaves; wipe them now and then so they can make the most of the light.

Toxicity

No toxicity is reported for dogs, cats or horses: the ponytail palm is listed among plants that are non-toxic to pets. As with any plant, though, eating the leaves can still cause mild stomach upset in a dog or cat.