Nematodes (also called roundworms or eelworms) are small, often microscopic, worms that are abundant in the soil and which may be either beneficial or damaging. There are thousands of different species, a few of which are sold as controls for garden pests while some are parasitic on plants, including daylilies. They may also spread plant viruses and rot pathogens. The presence of plant-parasitic nematodes may cause problems for daylily growers wishing to ship across state and international borders.
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