Grow colorful Vireya types as indoor-outdoor plants

Jim McCausland,  –  June 22, 2006

Strung out over the equator, the vast Malay Archipelago is the birthplace of a remarkable group of rhododendrons. These Vireya rhododendrons (also called Malesians) are quite different from their large, spring-blooming cousins that are so popular in the Pacific Northwest. Many Vireyas, with flowers in shades of red, orange, yellow, and white ― often intensely fragrant ― are small enough to fit in a tabletop pot. They flower heavily in winter, when their color and scent are most welcome, with repeat bloom several times each year.

You can grow Vireyas indoors anywhere, setting plants outside during frost-free months.

Vireyas rise again

Around the mid-19th century, Vireyas were the subject of a big breeding push in England. But most of the early Vireya hybrids were lost during World Wars I and II, when the English directed their resources toward survival. Interest was rekindled in the 1960s when Vireyas came to the United States. Today breeding is scattered across at least three continents, and there are hundreds of named varieties. How do you sort through them all? Our chart of 15 easy-to-grow Vireyas lists 15 reliable bloomers, with flowers ranging from long trumpets to dainty bells.

Growing tips
• Use a fast-draining potting medium. Or create your own mix by blending 1 part peat moss, 1 part ground bark, and 2 parts perlite. Put plants in terra-cotta containers that are relatively tall and barely wider than the rootballs (Vireyas grow best when they’re slightly rootbound).

• Keep plants in a bright spot indoors during the winter, and move them out into the light shade of a tall tree or covered patio during frost-free months (temperatures below 28° can injure or kill them).

• Like orchids, Vireyas like to dry out between waterings. Water by weight, at least at first. Pick up the pot and feel how much it weighs when the soil is dry. Then drench the soil and pick it up again ― it will be much heavier. This will give you a sense of how light the pot should be before you water again. Water more often when plants are blooming.

• Like rhododendrons in general, Vireyas are light feeders. Twice a year, in spring and fall, apply liquid fertilizer (20-20-20) diluted to half strength.

• Most plants will eventually grow at least 2 feet tall in containers, increasing bloom as they mature. If they get leggy, occasionally pinch new growth tips to force branching.

• Vireyas aren’t widely sold at retail nurseries. One excellent mail-order source is Bovees Nursery (1737 S.W. Coronado St., Portland, OR 97219; 800/435-9250; catalog $2), which sells more than 150 kinds at prices ranging from $7.50 to $35, plus shipping, for 1- to 5-year-old plants.

• The Rhododendron Species Foundation (253/927-6960) in Federal Way, Washington, sells Vireya species on-site and by mail. Some of the best include R. dianthosmum (pink with peach throat, carnation fragrance), R. dielsianum (rose), R. laetum (yellow), R. macgregoriae (saffron yellow), and R. wrightianum (red).

• For further reading, check out Vireyas: A Practical Gardening Guide, by John Kenyon and Jacqueline Walker (Timber Press, Portland, 1997; $19.95; 800/327-5680).