Part of the Rosette-forming Crassulaceae Project

Kingdom   Plantae
Phylum    Magnoliophyta
Class     Magnoliopsida (Dicotyledons) 
Sub-Class Rosidae
Order     Rosales
Family    Crassulaceae
Genus     Aeonium
Species   Approximately 35
Imagine a flat artichoke growing on the ends of tree branches -- this is what a lot of the aeonium species look like (in particular the arboreum species and it's hybrids).

Aeonium is a genus of monocarpic, rosette-forming crassulaceae, similar in appearance to jovibarba, echeveria, sempervivum, etc. It is a fast-growing succulent, with waxy leaves forming fairly flat rosettes. In situ, some species can form tree-like plants up to six feet tall, though most will grow as smaller shrubs. The star-shaped flowers range in colour from golden yellow, pale yellow, pink, red, or white. Seeds are powder-like. Natively, the plant lives in North Africa and the Canary Islands.

The most common species seen in cultivation is arboreum, loved by many for it's funky tree-like form. There are many hybrid variations which include variegated (striped) leaves, and striking colours (var. Schwartzkopf: dark puple-black, var. Atropurpureum: purple). Such hybrids are NOT naturally occuring.
CONDITIONS PREFERRED:

As with most similar genera of crassulaceae, this plant can survive in fairly poor soil, so long as it is well draining. This genera will not survive temperatures below 41°(fahrenheit). Strong light is required, particularly for plants which have dark coloured leaves (without strong light, the colour will fade significantly). Allow soil to dry to the touch between waterings, and avoid getting water on the rosettes. In hot environments, the plant will require some shade during the day, else the plants will scorch. This plant doesn't tolerate high humidity well.
PROPAGATION:

Tree-forming species can be propagated most easily through stem cuttings. Cut a branch several inches below a rosette, and allow the cut to callous. Place the cut end in slightly damp sand and do not water for one week. Water lightly. Once new growth is noted, repot in commercial cactus/succulent soil mix. This is a great way of preventing flowering in older rosettes.

New rosettes can also be propagated through leaf cuttings. Remove a young leaf near the center of a rosette, and allow the cut to callous for several hours. Place the leaf, cut-side down) in slightly damp sand. Soon a new rosette will form. Once adequate roots exist, remove the leaf and repot in commercial cactus/succulent soil mix.

It is best to pot at the end of summer, as the plant comes out of its dormant state.

Only some species will produce offsets.
PRUNING AND GENERAL CARE:

Pruning:
In general, this is a good plant to forget about. Leave it in a bright sunny location and water very sparingly. Remove any dead leaves from rosettes (particularly in low-growing species, as dead leaves invite rot and insects). When a rosette has flowered, it will die shortly. In tree-forming species, the whole branch will die, and new branches will grow in it's place. Mat-forming species will usually produce offshoots, allowing the plant to propagate itself, thus living on after flowering.

If a plant becomes leggy (long branches), cut off some rosettes and plant them as described above, this will encourage new branch formation and will discourage blooming.

Problems:
In the event of an unhealthy plant, the first thing to examine is your watering habits. The most common problem is root rot due to overwatering. If the soil is too wet, don't hope it will safely dry out so long as you don't water it for a while. Replace the soil immediately.

One of the most common pests to houseplants is the mealybug, and your aeonium may fall prey to this pest. However, due to the tightly packed leaves, more often than not the mealybugs will attack the roots. This makes them far less visible than mealybugs which attack leaf-stem junctions. The symptoms of a root mealybug infestation is slowed or stopped growth (though in summer this is a normal sign of dormancy). If this occurs without apparent cause, remove the plant from the pot and examine the roots. A white cottony substance on the roots and in the soil is a sure sign of mealybug infestation. Remove all soil and wash the roots gently. Remove any roots which appear damaged with a sharp sterile knife or scissors. Let them dry very throroughly before replanting.