Question: What are nematodes and what signs should I look for?
Answer: Nematodes are microscopic, worm-like organisms that feed on the roots of plants and turf grasses. They are one of the most destructive pests that cause ornamental plants to decline. The microscopic organisms feed on the roots of plants and cause various types of damage.
Root-knot nematodes cause gall growth or swelling to occur. Once plant roots are affected by nematodes, they become weak and fungi and bacteria cause even further damage.
Possible signs of nematode affected plants include poor growth, yellowing or bronzing of the foliage, loss of leaves, stem die back, failure to respond to fertilizer due to root damage and eventually the entire plant will die.
Nematode damaged plants usually show poor quality and die over a period of several years.
To determine if you have nematode problems, samples of root and soil must be sent to a nematode-testing lab for evaluation. This service often costs a small fee to process nematode samples.
You may pick up your free nematode sample collection kit from your local North Carolina Cooperative Extension Center.
Currently, there are no nematicides that can be applied to ornamentals for controlling nematodes.
If you do have a problem with nematodes, plan before planting. Avoid planting highly susceptible plants. Plants such as azaleas, camellias, yaupon holly, nandina, and others will grow satisfactorily. In existing landscapes with nematode problems, keep plants mulched and watered adequately during dry periods, make lime and fertilizer applications as needed based on soil testing report, and be sure to remove any dead branches. Plants with half or more decline in the above ground growth need to be removed and replaced with less susceptible plants.
Reminder: Please call the Sampson County Cooperative Extension Center at (910) 592-7161 with your horticultural questions and to register for any upcoming events. Be sure to check out the Ask An Expert Widget at sampson.ces.ncsu.edu for any questions you may have.