Root-knot nematodes (Meloidogyne spp.) are major pathogens of vegetables throughout the United States and world, impacting both the quantity and quality of marketable yields. In addition, root-knot nematodes interact with other plant pathogens, resulting in increased damage caused by other diseases. To date, only the northern root-knot nematode (NRKN; Meloidogyne hapla) has been found on vegetables grown on organic or mineral soil in New York, as it is able to survive the extreme low temperatures during winter. The NRKN has a wide host range consisting of more than 550 crop and weed species, including weeds common to muck soils such as dandelion (Taraxacum officinalis), purslane (Portulaca oleracea), mallow (Malva rotundifolia) and plantain (Plantago major). The increasing occurrence and damage of this nematode to onions, lettuce, and carrots grown on organic soils in New York was recently documented.