Common causes of orchid death include insufficient water, improper temperature, inadequate or excessive lighting and root rot. Many of these problems are easily corrected when discovered early. Root rot is the most severe problem and usually kills the plant.
The appearance of a dying orchid holds valuable clues as to the underlying problem. Orchids with wilting or falling blooms often need more water and a stable environment free from temperature extremes. Graying roots and green petal patches indicate that the plant needs more water.
Orchids with serious problems often display "bud blast," a phenomenon in which the plant jettisons new buds before they open. The causes of bud blast include inadequate lighting, temperature changes and touching the buds with bare hands. Orchids displaying bud blast must be moved to a brighter location and not touched without washing and drying hands.
Root rot occurs when the orchid's soil drains poorly and becomes flooded with water. Symptoms of rotten roots include gray coloration, softness and a powerful musty odor. The only way to salvage an orchid with rotten roots is to remove it from the wet soil so that the roots gradually dry. This process often takes more than a week. Once the roots are dry, plant them in clean soil.