WATERING

Watering is another important thing to get right. Most orchids are epiphytic. They grow on trees or other plants, and obtain their moisture from the air. Nutrients are obtained from rain carrying decaying matter over the roots. This means that they never stand in water in nature (Disas and Phragmipediums being noteworthy exceptions... but if you're getting into growing those, you need a lot more detailed information than this page is designed to provide). Accordingly, your orchids should not be allowed to stand in water in your home.

Orchids must be watered somewhat differently from most other plants, the most noticable difference being orchids' intolerance of dissolved salts.

How much water you need to provide, and how often, depends on several things:

How dry your conditions are.
The size of the pot.
The material the plant is potted in.
The type of plant.
How hot the weather is.
How actively the plant is growing.
How much wind the plant is expose to.
There really is no hard rule for watering that can be applied across all orchids, particularly bearing in mind that some homes are drier than others, small pots dry out faster than large ones, and some plants prefer more water than others.

In general, watch the plants -- they let you know when they need water. Crinkled leaves and shruken pseudobulbs are signs that more water is needed. The roots will tell you if you have good watering habits, too. Healthy roots are white, firm, and fleshy, with green tips, in plants that are not being overwatered (this is for genera that have velamen... Paphs, Phrags, and terrestrials are not included in this description). Overwatered plants have few good roots, and many soggy, mushy, brown, dead and otherwise rotting roots.

One watering rule you can live by is that most orchids tolerate being too dry much better than they tolerate being too wet.

When you water, let the water run freely through the pot. This helps to wash away mineral deposits and avoid salt buildup.

sources:orchidmania.com
photo courtesy of aka fortex