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Entomopathogenic nematodes nematodes under microscope

Nematodes: the Good, the Bad, and the Balance

June 08, 2017

Maybe you've seen beneficial nematodes for sale at your local organic gardening center. Or heard about nematodes attacking the roots of your neighbor's tomatoes. What's the difference? And what are nematodes, anyway?

Nematodes are round, threadlike organisms that eat organic material—from bad bugs and bacteria to plant roots—in your soil. Like the bacteria in our bodies, soil nematodes can be helpful or harmful, depending on the type and number present. A healthy balance of nematodes is key to the health of your soil's ecosystem.

Good nematodes:
• Break down soil nutrients so that plants can easily absorb them
• Eat pests like grubs, bad bugs, and fungus
• Harmed by synthetic fertilizers and pesticides

Bad nematodes:
• Eat plant roots

Want to make your soil friendly for beneficial nematodes? Make sure it is well-aerated; nematodes need plenty of space to move around. Kicking the chemical habit and adding compost to increase organic matter will help balance your soil's biology. When your soil biology is healthy, the less-desirable nematodes—and other pests—will be kept in check naturally.

Photo credit: D. Kucharski K. Kucharska / Shutterstock