How to Discourage Root Knot Nematodes in the Garden

Root Knot Nematode courtesy of www.mdinvasivesp.org

The nematode is a simple creature. It is an unsegmented worm and there are millions in our soils, many of which are beneficial. The root knot nematode lives in garden soil and can reek havoc on your plants. Particularly in the vegetable patch root knot nematodes can cause roots to swell, tangle, deform and severely weaken some plants like cabbage and Swiss chard. They will disfigure roots of others, like the carrot which can make them highly unappetizing.

Difficulty:

Easy

Instructions

1. Infected root courtesy of the Plant Disease Diagnostic Clinic, Cornell University

   The root knot nematode (Meloidogyne spp.) is a tiny worm-like creature that infests roots and causes them to deform into 'knots'.

2. The best way to avoid getting nematodes is to buy clean, healthy plants and keep your garden soil clean of old roots and debris. Mulching also helps.

3. Another way to avoid them is by rotating your crops so you won't attract them.

4. The French marigold is works as a supressive to this nasty nematode and these worms try to avoid it. That means that an attractive border of French marigolds will not only look great in the vegetable garden, but form a guard against the ravages of the root knot nematode.

5. If your soil already is home to these troublesome creatures, grow plants that are not susceptible.

6. Another way to deal with infested soil is to let it go fallow for a year or two until the nematodes are starved out. They live and grow in plant tissues.

7. You can also use soil sterilization by spreading black plastic out in the warm sunshine over the bare soil.

8. Since most pesticides that affect these nematodes are highly toxic and not readily available, you may need to remove and replace soil if none of these techniques work and root knot nematodes should become too much of a problem.

9. Obviously, the best way to deal with root knot nematodes is to avoid getting them in the first place. They are not uncommon, so I repeat, make sure plants and soil you bring in come from a safe supplier. They don't travel far in the soil so they have to be delivered to your site. There are many more beneficial nematodes in our soils that help keep soils healthy and actually prey on pests like the Japanese beetles. You can buy some of these nematodes from garden suppliers and retailers.

10. There are many more beneficial nematodes in our soils that help keep soils healthy and actually prey on pests like the Japanese beetles. You can buy some of these nematodes from garden suppliers and retailers.

Resources

• Gates & Croft Horticultural Design ideas and info