A monthly growers advice column by Courtney Hackney. Hackneau@comcast.net
Nothing is as basic to orchid culture as the orchid pot. There is more to the pot than just a container and selection of the best pot for your orchid plants can mean the difference between success and failure. The choice of growing container depends on the type of orchid being grown and the growing environment, i.e. your home or a greenhouse.
One of my favorite pots is the clear plastic type. They are generally produced using the same plastic and process as other orchid pots, but no color is added. Instead, a UV inhibitor is added to prevent sunlight from braking down the plastic. Occasionally, pots will be made and sold without the UV inhibitor and these pots discolor and disintegrate in just a few months in the sunlight.
Besides additional drainage, many plastic orchid pots have a raised bottom, which allows air to flow below and through the pot. All orchids hate stale air because it is depleted in oxygen. Orchids are now grown in just about every medium from those that retain water well, such as New Zealand or Chilean Sphagnum to various types of rock, including lava rock and Staylight.
The real beauty in a clear pot is the ability to determine the degree of wetness within the pot. I grow Paphs in lava rock. Paph roots prefer a constant moisture level. If their roots dry out the orchid suffers. In clear plastic, it is easy to tell when the moisture level drops because the inside of the pot can be easily observed. With lava rock there is never the chance that the medium will get too soggy as long as each rock is >¼” in diameter . It is also easy to observe the new roots because they like to grow along the inside of the pot where moisture precipitates from the change in temperature each night. Lava rock retains lots of moisture, but other types of rock typically do not.
Phals are often grown in clear plastic pots with New Zealand Sphagnum as the medium. Phals sold as pot plants often arrive in clear pots, the ones that degrade quickly in the sun. Phal roots will grow along the clear plastic side of the pot and seem to always grow best where the sun strikes the pot. Phals in this type of pot usually have big, fat roots that turn green if moist. If you purchase a phal in this medium and there are no roots growing along the inside of the pot you can be sure the plant was recently placed in this pot. Water only when the inside of the pot becomes very dry at least until new roots can be seen growing inside the pot.
In clear pots, Phal roots, which contain chlorophyll, can generate oxygen and aid root growth if watered properly. When moisture levels are low on the inside of the pot in the morning it is time to water. Often the surface will be so dry by this time that most folks would have already watered; which would have been too soon.
Most hobbyists grow in bark or some other organic medium. Clear pots allow an easy way to determine the degree of medium decomposition, which may vary greatly depending on the medium, fertilizer, and watering frequency.
Finding clear, plastic pots is not always easy and they can be prohibitively expensive compared to other plastic pots. My strategy is to try to have at least one plant of each orchid type, i.e. Phal, Paph, etc, in a clear pot on every bench to help me monitor the moisture condition in pots throughout the greenhouse. The only group of orchids that do not get this type of treatment are my cattleyas because they are all grown in clay pots. Does anyone know where I can get clear, clay pots? That would be ideal.
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