Aeonium arboreum
| Light | Bright light to full sun; a little afternoon shade in the hottest climates |
|---|---|
| Water | Regularly in autumn through spring while in growth; keep nearly dry through summer dormancy |
| Soil | Free-draining but slightly richer than a cactus mix — gritty with some organic matter (see Soil and potting mix) |
| Temperature | Frost-tender; best above about 5 °C, USDA zones 9b–11 |
| Propagation | Stem cuttings (very easy); also seed |
| Toxicity | Generally regarded as non-toxic to cats and dogs |
Aeonium arboreum is a branching, shrubby succulent native to Morocco, in north-west Africa, and widely naturalized and grown around the Mediterranean. It carries its flat rosettes of green leaves at the tips of woody, tree-like stems — hence the common name tree aeonium. It is one of the most widely grown members of Aeonium and the parent behind a great many of the dark-leaved and variegated cultivars found in cultivation.
Description
Aeonium arboreum grows as an upright, freely branching shrub, in time reaching roughly knee- to waist-height, with bare, greyish woody stems topped by rosettes of leaves. Each rosette is flat and spreading, made up of many thin, spoon-shaped leaves that are usually glossy green, often with fine hairs along the margins. Unlike many succulents the plant is winter-growing: it is most active in the cooler, wetter months and tends to rest in the heat of summer, when lower leaves may drop and the rosettes close up somewhat.
Mature plants produce tall, conical clusters of small yellow star-shaped flowers, generally in late winter or spring. Flowering rosettes are monocarpic — a rosette that blooms dies afterward — but because the plant branches so readily, the loss of one flowering head rarely troubles an established specimen.
Distribution and habitat
The species is native to rocky, coastal and hillside habitats of Morocco in north-west Africa, where it experiences mild, wet winters and dry summers. This seasonal rhythm explains its winter-growing habit in cultivation. It has long been grown and has become widely naturalized around the western Mediterranean. It thrives in bright, breezy positions with sharp drainage and tolerates poor, stony soils well.
Cultivation
Aeonium arboreum is an easy and forgiving plant, and among the most beginner-friendly succulents to grow. Give it plenty of light — bright sun keeps the rosettes tight and, in the coloured forms, brings out the best foliage tones — with just a little shading from the fiercest afternoon sun in hot, dry climates. Grow it in a free-draining mix that holds a touch more organic matter than a strict cactus blend.
Follow the plant's natural cycle when watering: water fairly generously through autumn, winter and spring while it is in active growth, and ease right off in summer, when it naturally slows down. It is frost-tender, so protect it from freezing; in cold regions it makes an excellent container plant that can be moved under cover for winter. Repot as the rosettes outgrow their pots — see Repotting for technique.
Propagation
Propagation could hardly be simpler. Stem cuttings root very readily: remove a rosette on a length of stem, let the cut end callus for a few days, then set it in a gritty mix and water lightly once it begins to root. This is the standard way to keep named cultivars true. The species can also be raised from seed, though seedlings of coloured or variegated forms will not necessarily resemble the parent. See Propagation — cuttings for a full walkthrough.
Cultivars
A. arboreum has given rise to many popular selections, prized for foliage colour and form. Notable examples include the deep purple-black ‘Zwartkop’ (Schwarzkopf), which colours most intensely in strong light, and various variegated forms with cream, yellow or pink margins. Crested and other novelty forms also appear in collections.
Common problems
- Etiolation — too little light stretches the stems and loosens the rosettes; move the plant somewhere brighter.
- Summer leaf drop — some shedding of lower leaves and closing of rosettes in summer is normal dormancy, not a sign of ill health; avoid the temptation to overwater a resting plant.
- Rot — soft, blackening stems usually follow overwatering, poor drainage or cold, wet conditions.
- Pests — mealybugs and aphids (especially on flower stalks) are the most common; watch for them tucked into the rosette centres.
See also
- Aeonium — the genus overview
- Propagation — cuttings · Soil and potting mix · Watering · Repotting · Pests and diseases