Bumps on an Orchid's Root

Orchid Roots

• Orchid roots absorb water and nutrients but are also an important support structure. Some orchids such as Vandas have aerial roots which start as small bumps on the stem and grow out. They help the plant support itself in arboreal habitats and can also absorb moisture through the air. The roots are slightly woody and brown to gray. Underground roots are a healthy grayish white color and plump and fleshy. The ends of the roots are colored usually green but sometimes in hues that match the flower color. The only time you should worry about coloration on the roots is if they are black. New roots will form as white bumps on the stems or near the pseudobulb or base of the plant.

Orchid Root Fungal Diseases

• Because of the moisture and humidity needed by orchids they are prey to numerous fungal problems. Fungi need moisture to bloom and reproduce. Some common fungal diseases case the roots to distort with bumps and pits. They usually begin to rot shortly after becoming disfigured. Black rot and root rot are two different fungi that will cause the orchid to lose vitality and eventually can kill it when the root system is fully involved. Black rot occurs when the plant is left standing in water and root rot is characterized by brown and black blotches on the stems.

Pruning Diseased Roots

• Anytime there are abnormalities on the roots of an orchid they should be cut out to prevent the spread of the disease. Some texture including bumps is natural on orchid roots. You can tell if the root is in trouble by pinching it and squeezing as you run your finger down. If the root leaches water or the outside skin pulls off, the root needs to go. You should cut the infected part off plus 1/2 inch of healthy tissue to ensure you got it all. Sterilize any cutting tools you use between cuts with household alcohol or bleach.

Trimming Roots for Repotting

• You will most likely discover any root problems during repotting which is done every two years. Use a good quality fir bark orchid mix that has been soaked overnight. Pots should only be an inch larger at each repotting since orchid growth is slow. The dry sheath around old pseudobulbs should be cut off as well as any discolored or stunted roots. Excessively long roots may also be pruned off. The entire root system is trimmed so it reaches 1/2 to 3/4 of the way to the bottom of the pot. Place a little medium in the bottom and then put the plant in, filling in around the roots.