A more natural way to grow orchids?

Thursday, February 4, 2010

Harry Phillips, who with his brother Andy operates Andy’s Orchids in Encinitas, Ca., made a strong case for growing epiphytic orchids mounted on hard wood when he spoke at the Orchid Society of Coral Gables this week: it’s easier to water; roots grow longer; plants grow best when in situations that imitate nature.

Orchid roots exposed on mounts benefit from good air circulation. The only orchid that doesn’t like good air movement around roots is the ghost orchid, he said. It prefers humid, close conditions like those deep within a swamp.

When watering, the entire mounted orchid should be irrigated for a long time, not just the roots on the lower part of the wood. “Typically people under-water orchids for fear of over-watering. But you usually cannot over-water orchids [on mounts].”

An orchid mounted on
hard wood.

The daylong rain that fell Monday was wonderful for orchids, which plump up their water-storing pseudobulbs during such events, and fatten their water-storing roots. “The duration of watering is the key,” he said.

In the summer rainy season, when does most rainfall occur? he asked. In the afternoon or evening. So Phillips recommends watering late in the day during warm weather to give plants on mounts a chance to stay wet longer. When watering in the morning in the summer, he said, exposed roots dry too quickly to fully absorb as much water as they need. (Most of us water early in the morning in South Florida and, in the hottest months of summer, mist orchids once or twice more in the afternoon to cool them. There could be a danger of fungal disease spreading if our orchids stay wet too long overnight.)

Phillips suggested mounting orchids on cedar or other hard woods, even upside down clay pots.  He also said that melaleuca branches are great for epiphytic orchids that will tuck roots into the papery bark.

The media between orchid roots and the wood should either be sphagnum, which holds water for a long time, or green moss, which drains better. The choice depends on the type of orchid being mounted. Cattleyas that need to dry their roots between waterings should be mounted using green moss; bulbophyllums and other orchids that like their roots to stay wet longer should be mounted with sphagnum. The exception, he said, are Phalaenopsis orchids. “Phals don’t like sphagnum,’’ he said. (Many South Florida hobbyist orchid growers use sphagnum for phals, repotting annually.)

To tie the plants onto the moss and mount, use 12-pound-test fishing line.

Buy a light meter to check how high or low the light conditions are; use a thermometer to keep track of temperature; use a single-edge razor blade when removing old roots and leaves. Use one blade per orchid, discarding each after use to avoid transmitting viruses and other diseases.

If some of these recommendations fly in the face of the way we grow orchids, perhaps they could be tested on a few plants in the coming months. Seems like a worthy effort.