Tree aeonium

Sun

Full sun to partial shade; give afternoon shade in hot inland climates and acclimatise indoor plants gradually to direct sun.

Water

Water thoroughly during cool-season growth, then let the soil dry substantially before watering again. Water sparingly during summer dormancy; never leave the pot standing in water.

Soil

Very free-draining sandy or gravelly soil. In containers, use cactus compost with added pumice, grit or perlite and a pot with drainage holes.

Height

3-6 ft (0.9-1.8 m)

Spread

2-3 ft (0.6-0.9 m)

Flowers

Mature plants may produce tall, branching clusters of small yellow flowers in late winter or spring. A flowering rosette dies afterward, but other branches usually continue growing.

Foliage

Evergreen. Fleshy, glossy green leaves in terminal rosettes, sometimes with reddish edges in strong light. Purple and nearly black foliage forms are also widely grown. Rosettes tighten and may shed lower leaves during summer dormancy.

Growth

Moderate during cool-season growth; slow or dormant in summer.

Care needed

Low

• Keep it frost-free; in colder regions, grow it in a pot and overwinter in a bright, cool indoor space.
• During active growth, water when the soil has dried substantially; reduce watering sharply when rosettes close in summer.
• Feed container plants lightly with a diluted balanced fertiliser once or twice during active growth.
• Keep mulch and fallen leaves away from the stem base; use a thin gravel dressing rather than moisture-retentive organic mulch.
• Place it where brittle branches will not be knocked by people, pets or strong wind.

Pruning. During active growth, shorten leggy stems just above a leaf scar to encourage branching, keeping some leafy shoots on the plant. Remove spent flowering branches once they have died back.

Spring

Repot crowded plants into a slightly larger container with fresh, free-draining compost.

Spring

Prune leggy growth and take stem cuttings while the plant is actively growing.

Late spring

In cold regions, move pots outdoors only after frost risk has passed, gradually increasing their exposure to sun.

Summer

Reduce watering if rosettes tighten and growth stops; protect from severe afternoon heat.

Autumn

Resume more regular watering as cooler weather brings fresh growth, but move pots under cover before frost.

Winter

Provide maximum light and frost protection; water cautiously indoors and shelter outdoor plants from prolonged soaking rain.

• Use a single mature plant in a plain container to emphasise its branching silhouette.
• Plant in raised gravel beds with aloes, echeverias and small agaves for contrasting rosette sizes.
• Use in sheltered coastal courtyards where mild winters allow permanent outdoor planting.
• Group green and dark-leaved forms beside pale paving or walls for foliage contrast.

Garden styles it suits: Architectural minimal, Modern Mediterranean, Modern courtyard, Dry gravel garden, Coastal and Small-space.

Plant it with: Echeveria, Blue chalk sticks, Aloe, Foxtail agave, Lavender and Rock rose.

Wildlife: Open yellow flowers provide nectar and pollen for visiting bees and other insects. Its wildlife value is limited when grown indoors or where it rarely flowers.

• Root or stem rot: soft, blackened tissue usually follows waterlogged conditions. Remove damaged material, improve drainage and salvage healthy stem tips as cuttings.
• Mealybugs: inspect rosette centres and stem joints for white cottony deposits. Isolate affected pots, remove small infestations by hand and use a labelled insecticidal soap if needed.
• Sunburn: sudden exposure to strong sun causes pale or brown patches. Acclimatise plants gradually and provide afternoon shade in hot climates.
• Frost damage: leaves and stems become translucent or collapse. Move plants under cover before frost and wait until damage is clear before cutting back to healthy tissue.

Not known to be toxic to cats, dogs, horses or people. No particular part is recognised as poisonous, although eating the leaves or stems may cause digestive upset; evidence for horses is limited.

Where it spreads. Can escape cultivation and spread from broken or discarded stems in coastal parts of New Zealand and southern Australia. Keep cuttings and garden waste out of coastal vegetation and bushland.

• Pinwheel aeonium (Aeonium haworthii)

  Usually forms a lower, denser shrub with smaller blue-green rosettes and conspicuous reddish, finely toothed leaf margins.

• Saucer plant (Aeonium undulatum)

  Has much larger rosettes with distinctly wavy leaf edges and usually fewer branches.

• Houseleek (Sempervivum tectorum)

  Forms low, ground-level rosettes and offsets rather than tall woody branches, and is far more cold-hardy.

Aeonium comes from a Greek word meaning everlasting, while arboreum means tree-like, referring to its woody, branching habit.

Propagation. Take a healthy leafy stem cutting during cool-season active growth. Let the cut end dry and callus for several days, then insert it into gritty compost; keep in bright indirect light and water lightly until rooted. Seed is possible, but named foliage forms do not reliably come true.

Accepted botanical name

Aeonium arboreum

In the US and Canada

Introduced in the lower 48 states.

Native range

Canary Is. and Morocco.

Measured

Average height 48 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.