Ice Cubes


I was shopping recently and saw a display of orchids with a sign “Orchids are easy as 1-2-3. Just add 3 ice cubes once a week”. Does this really work? Sara N.


Buyer beware! If orchids were this easy, there wouldn’t be instructional books, videos, and classes…or orchid societies, shows, and specialists…

There are three basic problems with these care instructions: (1) the amount of water, (2) the temperature of the water, and (3) and frequency of the water.

Exactly how much water is in three ice cubes? Conduct a simple experiment by placing three average size cubes into a measuring cup to melt. Within a few hours, the results are in: 3/8 cup water.

Is 3/8 cup of water sufficient to wet the roots? Conduct another experiment by gently removing the root ball from the pot after ‘watering’. The potting medium, typically sphagnum moss, is damp only on the top inch. Therefore, the lower roots will forever be dry and perish.

Successful growers ‘drench’ their orchids such that the potting media is thoroughly wet. Several cups of water flow thru each pot. The Laws of Physics don’t allow the stacking of the 15 to 20 ice cubes necessary to provide enough water!

The effect that water temperature has on plants is substantial. Landscape exhibitors at local flower shows are sometimes seen watering their large evergreen trees with buckets of ice so that the ‘slow thaw’ will keep the roots alive while not flooding the convention centers. Ice melts at 33 degrees F so top roots will be subjected to very cold droplets – something that native Virginia shrubbery are used to.

Tropical plants, however, are sensitive to cold temperatures and commercial growers are conscious of this - sometimes installing hot water heaters so as not to shock the roots. Phalaenopsis, in particular, require a very warm environment - at least 65 degrees F for trouble-free growth. In the rainforest, orchids receive moisture from clouds, streams, and rain. The temperatures are moderate - never hot or cold. The effect of melting ice on a tropical plant is, well, complete shock…and disbelief!

Aside from the quantity and temperature of water, today’s orchids need a watering frequency of about twice a week, particularly those that don’t have watering-storing pseudo-bulbs like Paphiopedilums and Phalaenopsis. Otherwise, the leaves go limp and the blossoms close early as the roots can’t find the necessary moisture. The potting media should never get ‘crunchy dry’.

Care instructions that promote 3 ice cubes a week will hook the buyer but doom the plants to an ill-fated life similar to Poinsettias; the plants are discarded after the short-lived flowers fold. Yet the real thrill of this sport is re-blooming the same orchid for years and years. Just ask my father who has many of his original plants from the 1940’s!



I’m a little worried about the 15 orchids in my apartment. The sunlight is good but the windows are leaky. What’s the lowest temperature permitted? Miles Q.


It’s a safe bet to keep most orchids between 60 and 90 degrees F year round. At this time of year, Phalaenopsis need slightly cooler nights to encourage flower spikes – usually in the mid 50’s for a few weeks - then it’s back to normal household temperatures. Drafty locations can be problematic for orchids – perhaps adding weather stripping, plastic sheeting, or, ideally, storm windows would do the trick! The motto should always be, “Anything for the orchids!” Amen. 

Thursday, October 1, 2009 - 17:45