Orchids Problems and Solutions

Environment

• Orchids are fussy when it comes to their environment. Like Goldilocks, they like every element of their habitat to be just right. This means a bright location spared from direct sunlight, 50 to 70 percent humidity and diluted fertilizer applications on a weekly or monthly basis -- but each type of orchid has slightly different needs than the next. If you provide the perfect environment for your particular type of orchid, you'll minimize the odds of experiencing many orchid problems.

Sunburn

• Sunburn is a major problem for orchids that sit in direct sunlight. In the wild, they usually grow beneath a canopy of jungle trees, where light is bright but dappled. Orchids experiencing a heavy beating from the hot sun have yellow, bleached leaves or crispy black spots. Move these orchids a foot or two away from the window or shade with a sheer curtain when the sun hits.

Overwatering

• Orchids prefer to dry slightly between waterings. Overwatering causes leaves to yellow and roots to rot. When orchids stay wet from watering or even high humidity, fungal diseases may develop, which leave markings on orchids and sometimes attract fungus gnats. You can prevent or eradicate these problems by cutting off rotten roots and repotting orchids. Water once or twice a week in the mornings, letting orchids dry before nightfall to prevent fungus.

Pests

• Orchids are prone to pests, including aphids, scales, mites and mealy bugs. They feed on orchids, leaving spots and sometimes causing blooms to die. In many cases, you can run water over the orchid to wash away bugs. Afterward, mist or lightly coat orchids with rubbing alcohol -- no other type of alcohol is safe -- to keep pests away. If you're growing orchids outside or in a greenhouse, introduce predatory insects into the orchids' habitat, such as wasps or ladybugs that attack aphids and mealy bugs. Carnivorous plants can help devour flying pests, such as fungus gnats. To battle a severe infestation, you can use an insecticide that has been tested on orchids, but only as a last resort.

Fertilizing

• Orchids are sensitive to over-fertilizing, especially as they require a diluted fertilizer. Fertilizer that is too strong -- a quarter-strength is recommended -- or too frequently applied can scorch orchid roots. On the other hand, gardeners who fail to fertilize their orchids may find that their plants don't bloom. Horticulturalist Kent Kobayashi recommends a monthly or bimonthly application of fertilizer on the University of Hawaii website. Most orchids prefer a fertilizer with an equal ratio of nitrogen, phosphorus and potassium -- such as 10-10-10 -- but orchids growing in bark need extra nitrogen.