Although now grown throughout the world, aloe plants origins can be traced to the African continent. The plants are native to sub-Saharan Africa, the Saudi Arabian peninsula and many islands of the western Indian Ocean, including Madagascar. With more than 400 species, aloes range in size from small houseplants to 30-foot trees.
The most commonly known aloes is aloe vera (Aloe barbadensis). Although hardy in U.S. Department of Agriculture plant hardiness zones 10 through 12, it is normally grown indoors. As a houseplant, it thrives in well-drained potting soil, tolerates some shade, but does best in full sun. The spiral aloe (Aloe polyphylla), a 6- to 12-inch tall and wide plant, has spine-tipped leaves that grow in a spiral. Mature plants have five rows of leaves growing either clockwise or counterclockwise. Hardy outdoors only in USDA zone 11, the plant thrives in well-drained potting soil in full sun or light shade.
At 1 to 3 feet tall and wide, the red aloe (Aloe cameronii) provides a unique color blend for your landscape. The plant's foliage varies from green to a deep burgundy depending on sun and water. When it matures, it has red-purple mounds with orange flowers, and is hardy in USDA zones 9 through 11. The spider aloe (Aloe humilis) is only 4 to 5 inches tall and wide. In the spring, it produces a 1-foot long spike topped with tubular red blooms that attract hummingbirds. This plant thrives in light shade and is hardy in USDA zones 9 through 11. It is also used as a bonsai plant.
At more than 8 feet tall, the yellow torch aloe (Aloe "Yellow Torch") adds a bold visual texture as a backdrop to any bed. Its torch-like clusters of yellow flowers bloom from late fall through late winter and provide a stark contrast to the plant’s upright gray-green leaves. The yellow torch is hardy in USDA zones 9 through 11. Planted for its striking form, tree aloe (Aloe arborescens) is a slow-growing plant adorned with pink or orange tubular flowers. Reliably hardy in USDA zones 10 and 11, it is sometimes grown in zone 9b. The tree aloe gains greater cold tolerance as it matures.
The gel from aloe vera is used is cosmetics. Aloe vera is considered non-poisonous to humans, but it can be harmful to dogs or cats if ingested. If you suspect your pet has consumed the plant, immediately contact your veterinarian, the ASPCA advises.
- The University of California Davis Botanical Conservatory Botanical Notes: The Genus Aloe
- Missouri Botanical Garden: Aloe Vera
- Fine Gardening Plant Guide: Spiral Aloe (Aloe Polyphylla)
- Fine Gardening Plant Guide: Red Aloe (Aloe Cameronii)
- Fine Gardening: 10 Outstanding Succulents
- Botanical Journey Plant Guide: The Architectural Aloe Tree
- ASPCA: Aloe
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