Proper Watering Practices
Orchids thrive in unusual circumstances in the wild. They adapted to cling to trees, rocks or make a home in leaf litter on the forest floor. They receive water wherever it happens to fall - down the side of a tree, dripping from the leaves on a branch, sliding down the side of rocks.
But, unlike most plants, where they don't usually receive water in nature is from the dirt. The media they grow in is not earth, though some will bloom in very sandy soil.
Those natural conditions provide clues to the proper watering practices, which will vary somewhat depending on the species category in question. Epiphytes, for example, cling to trees, while saprophytes grow in leaf litter. But one thing is true of all orchids, overwatering is a much greater danger than underwatering.
Most orchids will do well with modest weekly watering. How 'modest' is modest depends, of course, on the size of the pot and plant, along with the specific species. Beyond water in the medium, it's important to keep some moisture in the environment.
Most enjoy humidity between 40-70%. A more accurate number can be gained by considering the plant's native habitat. Those from the jungles of Hawaii will enjoy a bit more than the more temperate and dryer regions.
That amount of moisture - in the growing media and in the surrounding air - is a lot easier to maintain than it might seem.
Provided you allow for good drainage by using the correct type and size of bark chips, lava rock and other media, any excess will drain away. Giving them a good porous medium to grow in helps prevent excess watering and also gives good air flow.
The roots should not sit in any excess, but that's easily obtained by the proper type of pot. To keep the air humidity level just right, simple automatic humidity trays, misters and so forth are easy to obtain. You may have seen one in the pot of your favorite bonsai tree display.
Terrestrial orchids that grow in sand can tolerate a bit more than other types, but here too care is needed. Sandy soil provides very good drainage but it can easily plug the holes in a pot. That puts the roots continually in a shallow layer of water. That will lead to root rot. Be sure the holes have small screens.
Watering needs will also vary with the season. During the active growing season a little more is called for. During the late Fall and Winter, a dry season of six to eight weeks is not harmful. It begins after the plant has had its growth spurt for the year. At that time of year, water should be reduced but not entirely eliminated. That will aid in initiating flowering.
Watering can be done regularly, but should be done lightly. Unlike bonsai, orchids do not usually thrive when drenched then left to dry out. But they do enjoy the occasional spraying with water or a weak water/fertilizer mixture, beyond the water in the medium.
