Healthy vs. Dead Orchid Roots

Healthy Roots

• Healthy orchid roots are very firm and fat, covered in white velamen with light green tips. They are easily broken during disturbances like repotting, so it is important to proceed slowly and with great care when transplanting an orchid to avoid unnecessary damage. Paphiopedilum, commonly known as Lady Slipper orchids, have brown roots with tiny visible hairs all over them that absorb water. The plant's roots are extremely delicate and react poorly to salts in water or in fertilizer. Always use weak fertilizer solutions on Paphs -- about a teaspoon per gallon of water.

Root Rot

• Roots that are too wet, overwatered or standing in water will rot. They look brown, soggy, limp and may even blacken and develop fungus. Avoid this by repotting the plant annually or every two years as the potting medium breaks down and becomes fine, not chunky. Old potting mediums hold too much water and can kill an orchid plant, so ensure the water flows through the medium and out of the pot during watering. Never leave an orchid in standing water. Some growers water potted orchids in a sink and then return them to their display area so there is never a chance for water to collect around the roots. Rotted roots should be cut away with a sterile knife when the plant is repotted. Cut at least a half-inch of the healthy root away above the dead part to ensure you have removed all of the rot.

Dried Roots

• Roots that are withered or hard with skinny tips are also in trouble or beyond help. The plant isn't getting the humidity it needs to thrive and the roots are dried and very likely dead. You can try cutting the dried part of the root away with a sterile blade and repotting. If enough roots are still healthy you may be able to save the plant. To keep orchids happy, their growing area should be between 60 to 80 percent humidity -- a good humidity level for most plants but higher than most heated homes provide in winter. Add a tray of water filled with pebbles beneath orchid plants to provide more moisture, but keep the plants above the water level.

Phalaenopsis Roots

• Phalaenopsis orchids, or "Moth" orchids, photosynthesize through both leaves and roots. The plants like roots exposed to the light so one way to keep them thriving is to use a clear pot that lets you see the roots and allows them to absorb sunlight.