Watering Basics

Probably more orchids are killed by improper watering, usually by OVER watering, than by any other cultural practice. Discovering how to properly water orchids is one of the more challenging aspects of growing orchids.

“How often should I water my orchids?” This question never has an easy answer. There are so many variables involved in watering. The following sections cover some of the factors that affect how often you should water.

  • Type of Pot

Orchids can be grown in clay or plastic pots. The potting material dries off much more slowly in plastic pots than it does in clay pots. With plastic, the potting material dries out from the top down, so even though the potting material may be dry on top, it may be damp just below the surface. With clay pots, the potting material dries out more uniformly. Clay pots are porous, so they “breathe” and allow water to evaporate through the walls of the pot.

Either type of pot will grow orchids, they merely have different watering requirements. For orchids that do best when they’re always slightly damp, like Miltonias, Paphiopedilums, and Phalaeonpsis use plastic pots. For those that need to dry out more between waterings like Cattleyas and most Dendrobiums, use clay pots.

The bottom line: If you’re using a plastic pot, you’ll want to water less often than if you’re using a clay pot.

Of course some orchids prefer to be hung in baskets or mounted.  These orchids often require a higher level of humidity, and more frequent waterings as they have little or no medium surrounding the roots.

  • Potting Material

Potting materials vary dramatically in terms of the amount of water they retain. Sphagnum moss, for example, is highly water-absorbent, and usually stays wet much longer than typical tree fern bark, which comparably is far less water-retentive. If you are using a potting material that is highly absorbent, you’ll want to water less frequently than if you use a potting material that is not water retentive.

To determine whether the potting material is absorbent or not, soak some of it in water for a few hours. When you remove the material, squeeze it. If the material is absorbent, under the pressure it will release this water, like a sponge.

  • Age of the Potting Material

Fresh potting material requires much more frequent watering for the first few weeks, until it gets properly wetted. As it gets older, it retains water longer.

  • Whether the Orchid is Pot-Bound, or not…

An overgrown orchid, often referred to as an orchid that is pot-bound, will dry off much more quickly than one that has plenty of space in the pot. When pot space is limited, there is less potting material to hold onto the water, so the overgrown plant quickly uses it up.

In general, most orchids need to be repotted every one to two years.

  • Growing Environment

Are you growing your orchids in high humidity or low? In a area that has low humidity, the air that is more dry, and quickly absorbs the moisture from both the plant and the potting material.

  • Temperature

Warmer temperatures increase water evaporation because warmer air absorbs more moisture. Plants growing in warmer temperatures tend to require more water. If you’re growing orchids in a cooler temperature, you should not need to water as often.

  • Amount of Ventilation

The more ventilation your orchids get – especially if air is vented to the outside, or if the air is hot and dry, as found in most centrally heated homes – the quicker the water in the potting material evaporates. Gentle air movement is ideal as it will keep the air fresh without excessively drying out the plants or potting material.

  • Whether the Orchids are Growing or Dormant

Certain species of orchids require a winter rest period, and at this time should be given very little water. When they regain active growth in the spring and summer, they require copious amounts of water.

  • Type of Orchid

Some orchids, like Cattleyas, like to dry out between waterings; others, like Paphiopedilums, Phalaenopsis, and Miltonias, prefer to always be slightly damp. This difference has a lot to do with the natural environment of the particular species. If the orchid naturally grows in an area where it is devoid of natural rainfall on a regular basis, it will not need watering as often as orchids that grow in areas of frequent rainfall.

When you buy an orchid remember to obtain a label with the genus and species information. Species of orchids can have widely different needs than other species found in their same genera. This information is necessary to determine the exact needs of the plant.

The above is a modified excerpt from the book Orchid for Dummies.

About

Welcome to Jardim Therapy my blog about orchids and Brazil. Here you will find a few useful references, and some tip & tricks, along with posting of my own personal experience. I absolutely love orchids, and I want to help everyone interested in learning about these unique plants.

As guests of Jardim Therapy you are welcome to browse the home page, post comments, and access the archives. You can also send me a message if you have any questions.

Enjoy!

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