Unusual Houseplants: Arboreum

Arboreum is a species of Aeonium, a family of plants that include a large variety of succulents. All of the plants within this family have distinctive "leaves" that form rosettes on the ends of their stems. Colors vary from a very light green to almost black. (There are also some variegated forms.) Heights vary, as well. Some species are so short that they look as if they have no stems. The arboreums, however, can grow to be 3-feet-tall.

Most people know this species of plants through their more popular cultivars. These include the following:
'Schwarzkopf': Has almost completely black foliage.
'Black Rose': Another variety with black foliage.
'Atropurpureum': Deep purple foliage

As you may have guessed by now, arboreums are grown primarily for their unusually shaped and colored foliage. They do produce flowers; however, this is not the main reason to grow these plants. In fact, it can take 4-5 years before an arboreum with flower -- if it ever does indoors. (You probably do not want your arboreum to bloom anyway, since the rosette from which the flower springs will die with the flower. Therefore, if your plant only has one rosette, you have lost the entire plant.) To encourage the growth of the foliage and to maintain its marvelous color, certain conditions need to be met.

Arboreums (like all Aeoniums) should be planted in a potting mix designed specifically for cactus and/or succulents. If you do not have such a mix on-hand, just add coarse sand or perlite to your standard potting mix -- generally one-part sand/perlite to two-parts standard potting soil. Arboreums also need lots of direct light, especially since cultivars in this group have such deeply colored leaves. Light is needed to bring out and maintain the color. (The color is not as vivid and intense if these plants do not get enough light.) The various arboreums also like warm temperatures in the summer; therefore, summering them outdoors is always a good idea. In the winter, they prefer cooler temperatures, which gives them a chance to rest. They also like low humidity, which means that the normal temperatures and humidity in your house will suit them just fine.

Do not over water these plants. They can easily succumb to root rot. (Providing good drainage is a must, which is why you should use a cactus/succulent potting mix, as mentioned above.) Instead, allow the soil to dry out slightly between waterings. In the winter when they go dormant, you will want to water them even less. A Seasonal Guide to Caring for Houseplants.]

Arboreums are easily propagated from seed or stem cuttings. Be sure to start in a cactus/succulent mix. These are extremely easy-to-grow plants and can add some real color and interest to your indoor garden.

References:

Horan, Anne and Robert G. Mason, eds. Foliage Houseplants. Alexandria, VA: Time-Life Books, 1988.

Huxley, Anthony. Success with House Plants. Pleasantville, NY: The Reader's Digest Association, Inc., 1979.