How Often Should an Orchid Be Watered?

Watering Time

• Although orchids are native to tropical rainforests, it is a mistake to think that they need very frequent watering. Overwatering causes orchid roots to rot and the plant can die. Each type of orchid has its own moisture requirements, which can change with seasons and temperatures. To know whether an orchid needs water, the American Orchid Society recommends testing its soil with your finger. Push your finger into the soil, approximately 1 inch deep, to get near the roots. If the soil feels wet, the plant should not be watered. If you are uncertain whether the plant is dry, wait one more day to water.

Watering Factors

• Various factors affect watering frequency, notes Kent Kobayashi of the University of Hawaii at Manoa. When it is not growing season, orchids require less water than when they are growing or blossoming. Orchids with thinner foliage generally require more water than those with harder, more succulent leaves and thick fleshy stems or "pseudobulbs" that hold water, like those of epiphytic orchids. The type of medium orchids grow in also affects watering frequency. Bark typically dries out faster than other growing mediums.

Watering Instructions

• The American Orchid Society advises watering plants in kitchen sinks using lukewarm water that is not salt-softened or distilled; heavily chlorinated tap water can also be harmful. Rainwater is good. The society recommends watering the plant for approximately 15 seconds, thoroughly wetting the growing medium. Allow the plant to drain in the sink for about 15 minutes. The plant may then appear dry but does not require more water. Do not allow the plant to stand in water.

Epiphytic Orchids

• Most orchids are epiphytic orchids, which means they get water and nutrients from the air through white, thick, aerial roots. They also grow on the branches of tropical trees, absorbing moisture from bark surfaces covered with dew or rainfall. Epiphytic orchids require an orchid mix, such as those made of coarse bark chunks, that does not absorb much moisture. Many epiphytes have upright swollen stems called "pseudobulbs," which store food and water. If these epiphytes are planted in osmunda, which is a mix of roots from the osmunda fern, they might need water every 3 or 4 days. They may need more frequent watering if they are planted in bark. Epiphytes without storage structures might need water daily. Terrestrial orchids are potted in a more typical houseplant mix that holds some moisture but is well-draining.

Providing Humidity

• Orchids prefer humidity levels between 40 and 60 percent. Homes with enough moisture for common houseplants to thrive, will usually meet orchids' needs, according to Kobayashi. Orchid growers can always check information about their variety to determine the best humidity levels. If humidity is low, such as during the winter months, it can be raised by misting orchid leaves every morning or by using a small humidifier. Smithsonian Gardens recommends placing orchids in a tray filled with gravel and water, with the orchids sitting on gravel above the water level. The water will evaporate around the plants, creating humidity. Place plants far enough apart so air is able to circulate well, preventing disease.