Burro's tail

Identification and origin

Sedum morganianum belongs to the stonecrop family, Crassulaceae. It is native to Mexico, particularly the central, Gulf, and southeastern regions of the country (Veracruz, Puebla, Chiapas), and has become naturalized in the Dominican Republic. It has long been grown as an ornamental for its distinctive evergreen foliage.

It is a succulent, evergreen subshrub, tender to cold but very long-lived: indoors, a well-placed plant can last for decades. The stems grow upright at first, then hang down and lengthen to 2 ft, sometimes 3–4 ft on old plants; full of stored water, they become heavy. The leaves, less than 1 in long, are thick, almost cylindrical, and pointed. Arranged in a tight spiral, they overlap and completely surround the stem, giving it a braided look. Their blue-green color comes from a thin silvery bloom that rubs off when handled. Well watered, they are plump; when short of water, they shrivel.

Stems and leaves are fragile: the leaves drop at the slightest knock. Place the plant away from foot traffic, where no one will brush against it. Bare sections of stem can produce new branches.

In summer, mature plants sometimes bear clusters of one to six small, star-shaped pink to red flowers at the stem tips, about 0 in across, with five petals and bright yellow stamens. Rich in nectar, they attract bees and flies. Flowering is rare indoors: stems must be at least 10 in long, and a summer outdoors followed by a cooler winter encourages it. The cultivar ‘Burrito’, whose exact status remains unclear, has smaller, rounder, lighter green leaves on shorter stems.

Light

It grows best in bright light to full sun: a windowsill that gets at least a few hours of direct sun suits it. In too little light, the internodes lengthen and the leaves spread apart, leaving the stems looking sparse. Conversely, light that is too intense bleaches the foliage, which turns yellowish instead of blue-green; a red-brown tinge in summer behind south-facing glass signals sunburn.

It can spend the warm season outdoors, hanging in a spot sheltered from wind. Acclimate it gradually to outdoor light over one to two weeks, and shield it from the strongest midday sun to prevent burning.

Watering

Like any succulent, it handles excess water poorly, especially during its winter rest. During the growing season, water thoroughly with tepid water once the mix is nearly dry, let it drain, and empty the saucer after about 15 minutes. Water less often in fall; in winter, give just enough to keep the mix from drying out completely. The cooler and dimmer the room, the longer the gaps between waterings.

The leaves are the best guide: plump means all is well; shriveled means the plant is thirsty; soft and limp while the mix is damp means it is getting too much water. There is no need to mist: it does not need humid air.

Potting mix

It needs a very free-draining mix: a cactus mix, or a regular potting mix generously amended with perlite, pumice, baked clay granules, or fine gravel. Avoid fine sand, which fills the pore spaces instead of opening them. It prefers a neutral to slightly alkaline pH. Choose a shallow pot, always with a drainage hole; hanging baskets and urns on pedestals show off the trailing stems.

Its nutrient needs are modest: one or two doses of diluted fertilizer during the growing season are enough. Avoid high-nitrogen fertilizers.

Temperature

Indoors, days between 61–75 °F and cooler nights suit it; a clear drop in temperature from day to night is needed for good growth. A somewhat cooler winter, between 50–68 °F, can encourage flowering. It tolerates brief dips to 39 °F but not frost.

Move it outside only once temperatures stay consistently above 39 °F, and bring it back in during fall as soon as nights are forecast to drop below that point. It appreciates fresh, moving air. It can be grown in the ground only in USDA zones 10a to 11b, in well-drained soil, even poor or rocky ground.

Repotting

It grows very well when pot-bound: repot in spring only when it has completely filled its pot. Handle it with great care, since every touch knocks off leaves. After repotting, wait about a week before watering, then water sparingly until it settles in.

Pruning

No pruning is needed. Fallen leaves and broken bits of stem are not wasted: use them for propagation.

Propagation

Nothing could be easier. For a stem cutting, strip the leaves from the lower end of a piece, let it dry for a day or two so the cut can callus, then push it into a barely moist, free-draining mix. Secure long or heavy cuttings with a pin or small stake until roots anchor them. Full rooting can take several months.

Detached leaves also root: lay them on a lightly moist, free-draining mix, but expect a new plant to take longer than from a stem. Division and seed, sown in early spring at 59–64 °F, are also possible.

Common problems

• Mushy base, collapsing stems: crown or root rot, usually caused by overwatering or a poorly draining mix.
• Soft, limp leaves: mix too wet.
• Shriveled leaves: too little water.
• Sparse stems, widely spaced leaves: too little light.
• Yellowish or red-brown foliage: light too intense, or sunburn.
• Heavy leaf drop: knocks and handling.
• Pests: mealybugs on the stems, scale insects, vine weevil grubs in the mix; outdoors, slugs and snails.

The same symptom can have several causes: look at the mix, the light, and the temperature together before drawing conclusions.

Toxicity

No toxicity is reported: burro’s tail is classified as non-toxic to dogs, cats, and horses. Its stems and leaves are even edible, but eaten in large quantities they can cause stomach upset.