Hot Summer Growing


Can orchids take the blazing hot summer days we have been having lately? Max C.


For the most part, epiphytic plants of all kinds love the Virginia summers with their high humidity, gentle breezes and warm temperatures. But this year might be the exception as triple digit thermometer readings have become the norm. Orchids are commonly found in tropical cloud forests that rarely exceed 90 degrees F.

Cultural extremes can cause ‘botanical stress’ whose symptoms vary from yellowing leaves to shriveled pseudo-bulbs to droopy flowers. Though permanent damage is not likely to occur, plants may get ‘stunted’ for a year or two before they regain their vigor again. Orchids are slow growers to begin with so it’s always advisable to give them optimum conditions so that they will bloom annually. Daily temperatures of 105 degrees F for weeks at a time will certainly stress most orchids.

There are several options available to novice growers when summers get unbearably hot. The first is to keep the plants in the shade during the heat wave. Although the light levels may be lower than normal, the far more dangerous temperature threat will be reduced. Another idea is to spray the leaves down with tepid water several times a day (cold water will ‘shock’ plants) being careful not to let any Phalaenopsis crowns remain wet at nightfall. Also, increasing the air movement around the plants can significantly lower leaf surface temperatures. Hanging plants from tree limbs or using an outside fan can assist with this effort. As a last resort, bring the plants inside until seasonal weather returns.



Is it possible to identify an orchid from a photo? I have a plant that my mother left me when she died 30 years ago and I have never known its name. Norman H.


Plants with lost name tags are a common occurrence in the orchid world. Though the original grower always puts a ‘genera/hybrid/variety’ identification label on each plant in production, it seems that this important information often gets lost along the way. Over the years, the orchid may be re-potted and split into pieces but the owner doesn’t write a new tag for each division. Before long, there are nameless plants in circulation everywhere.

Some orchids are immediately identifiable by an expert upon sight of the flowers. Occasionally, the foliage alone yields the name. The vast majority of ‘no names’, however, remain as such due to the literally hundreds of thousands of possible hybrids in the world. A rank novice can determine the genera of common orchids strictly from the foliage. Cattleyas, Dendrobiums, and Oncidiums all have tell-tale pseudo-bulb shapes while Phalaenopsis and Paphiopedilums have uniquely tapered leaves. Even less common types such as Cymbidiums, Miltonias, and Vandas are easy to identify.

The exact hybrid name is much more challenging unless the plant was mass produced by cloning (exact duplication) in which case the variety name might also be known (Example Oncidium Sharry Baby ‘Sweet Fragrance’).

Orchids that have been out of circulation for three decades likes your mother’s plant would require an ‘expert in advanced years’ to identify. I’ll forward your picture to my father who just turned 80 and tends to his collection daily... 

Thursday, July 1, 2010 - 17:30