What is Epidendrum?

Epidendrum is a genus of flowering plants that includes hundreds of species of orchids. The name epidendrum is derived from the Latin word epi, which means on, and dendron, which means tree. This aptly describes the growing habit of most epidendrum orchids, since they are plants that grow on top of other plants. The genus also consists of some orchid species that grow on rocks and a select few orchid species that grow on the ground. Epidendrums are native to Mexico, Central America, states south of South Carolina, and some countries of South America, including Argentina.

Generally, epidendrums are durable plants that can be grown in flower pots, cork slabs, or raised flower beds. A wide range of arrangements can be created with the differing sizes, shapes, and colors of epidendrums. The flowers of epidendrums are generally between 1 and 6 inches (about 2.5 to 15 cm) in diameter and can appear as short bulbs, pseudobulbs, reed-like stems, or canes. Nearly all epidendrums have an attractive fragrance and most are brightly colored. Pruning typically involves the removal of old flower spikes and stems at the base to prevent the formation of short spikes and a tangled appearance.

Epidendrums can thrive in soil conditions that are less than adequate, so any type of planting mix will do. The key requirement for a healthy epidendrum is the fertilizer. A balanced fertilizer generally promotes thicker flowers, greener leaves and efficient roots. In certain growing conditions, such as reduced lighting, a fertilizer with a smaller percentage of nitrogen is generally recommended. Epidendrums grown in low-light conditions with fertilizer that contains a high amount of nitrogen typically produce thin, dangling growths.

Another consideration when starting an epidendrum flower bed is the temperature. Epidendrums are hardy plants that tolerate a range of temperatures. Generally, the daytime temperature should be 60 to 90° F (about 15 to 32° C), and the nighttime temperature shouldn't drop below 30° F (about -1° C). In northern climates, the flowers should be moved inside at the first frost and moved back outside after the final frost.

Pest infestation and fungal infections are additional concerns associated with growing epidendrums. Aphids, slugs, snails, ants, and scales typically damage the flowers and leaves of the epidendrum. The root fungus rhizoctonia and the tobacco mosaic virus are two infections that can severely damage epidendrums. Generally, insecticidal soap is used to protect epidendrums from insect damage and fungicides are used to prevent fungal spores from infecting the plant.