We see them in our neighbors' yards, along driveways, and sometimes along mountain roadways. Reed-stem epidendrums — orchids named for their long, slender stems — have been popular in Hawai'i for years. Easy to grow, they come in a wide array of colors (white, red, orange, pink, lavender, yellow, and even some multicolored forms), they bloom for a long time and are relatively inexpensive.

Three common epidendrum species cultivated in Hawai'i, where they're locally called epis, are E. radicans, E. ibaguense and E. cinnabarinum.

Native to the Central America, radicans has a low-lying growth habit that is freely branching, producing roots along the length of the stem. Flower spikes are upright, normally 6 to 15 inches high, with up to 10 vivid, reddish-orange, one-inch flowers that open in succession over several months.

E. ibaguense, a native of Colombia and Venezuela, grows like radicans, but has a growth habit that is more clumping, with roots on the lower half of the stem. Flower spikes are up to 18 inches long and end in a dense head of 1-inch reddish to yellow to purple flowers, up to 50 flowers per stem with 20 open at one time. Because of their sprawling growth habits, radicans and ibaguense (and their hybrids) are ideal for growing outdoors in ground beds.

E. cinnabarinum, from Brazil, is robust, erect and clumping in its growth habit, often growing to 4 feet tall. Thirty-inch-tall spikes produce dense heads of up to 40 flowers, with as many as 10 open at a time. The large flowers grow to 2 inches wide and are colored from red to orange to pink with a yellow lip.

Local hybridizers have combined the best characteristics of different species to produce modern reed-stem epis that have brighter colors, grow sturdier and bigger, with more flowers. A good example is Hokulea, which is a hybrid of Joseph Lii and cinnabarinum, created by Gavin Yamada of Puanani Orchids in Waimanalo.

A superior cultivar named Mackie, grown and displayed by Wayne Ajimura of Hana-pepe, won a first class certificate from the American Orchid Society. It had 331 flowers on five huge heads of reddish-orange 1-inch flowers that formed perfect balls. This giant orchid was more than 6feet tall — an epi on steroids!

Reed-stem epis are grown in a greenhouse or more commonly outdoors. In areas close to the mountains where there is natural cloud cover, they don't require shade. Hotter areas of the Islands would require midday shading to prevent the sun burning the foliage. Potting medium for outdoor planter beds can be made up of a peat-and-perlite-based potting mix blended with equal parts of black cinder. In pots, equal parts of medium or fine orchid bark, peat moss and perlite, would work fine, especially, if you are growing some of the cinnabarinum hybrids, which may require better drainage.

In all cases, epis require an even amount of moisture and don't like to completely dry out. Fertilize with a balanced timed-release fertilizer or twice monthly if you are using a foliar fertilizer. Well-fed plants will start flowering in the spring and stay in flower until the end of the year. There are not many pests that bother epis in Hawai'i. Watch for aphids and thrips on the flowers and treat with an insecticidal soap or any general insecticide. In the wetter months, treat the growing areas with metaldehyde bait for slugs and snails.

Epis are easy to propagate. Just snap of the keiki (aerial offshoots) when the roots are 1 to 2 inches long, plant in a small pot of sphagnum moss or into the potting mixture and the keiki can bloom within a year's time.

Anyone can grow reed-stem epidendrums in Hawai'i. There are few plants that can give such a riot of color all summer long for so little effort.

Scot Mitamura is a horticulturist and orchid specialist for the Honolulu botanical gardens. Reach him at hbg@honolulu.gov.