Gardening With Laurie: One of the good guys

Feb. 1, 2011 at midnight
Updated Feb. 2, 2011 at 8:03 p.m.

Laurie Garretson

Laurie Garretson

By Laurie Garretson

Mention the word nematode to many people, especially gardeners, and they immediately think of the little pest that wreaks havoc in vegetable gardens.

There are actually more than 20,000 different kinds of nematodes. Many of them are pests, but there are also many more types of nematodes that are very beneficial. Beneficial nematodes can be very helpful to people.

Nematodes are microscopic worms that live under the soil. Many of the beneficial types of nematodes kill unwanted pests before they even become adults. When the good nematodes find pests, they enter the pests through body openings. Once inside the host body, the nematode ejects a bacteria that multiplies and causes the pest to die. This all happens within about 48 hours. The same bacteria that killed the pest then converts the dead host's tissue into nourishment for the nematode. The nematode feeds on the dead remains and multiplies inside the dead insect until all the food source is used up. The nematode leaves the dead insect and then goes in search of its next victim.

Beneficial nematodes are present in our soils but usually only in small numbers. Why? Well, synthetic chemicals have killed off most of the life in all our soils. Man has used too many chemicals, for too many years, on the soil without adding any form of organic matter back to it. When you garden naturally, using only natural products, you add this life (organic matter) back to the soil and make it possible for nature to again "do her thing." Life comes back to the soil.

This is the time of year when beneficial nematodes can be a huge help at getting rid of many of the pests that overwinter in our soils. One of those overwintering in our soils right now are thrips. These tiny pests are the culprits that destroy so many of our beautiful flowers and other crops. Thrips damage is usually noticed on flowering shrubs such as roses. Thrips love to feed on flower buds. Of course, a damaged bud means a damaged flower. Applied to the soil now, the beneficial nematodes can help to get rid of these pests. Beneficial nematodes are easy to apply and are a totally safe biological pest-control method.

Fleas are so often a problem for pet owners. Having a good population of the nematodes built up in your soils will help to eliminate this pest.

For anyone who has ever had walnut caterpillars in their pecan or oak trees, you should apply a good amount of the nematodes to all the area under and around your trees. This caterpillar overwinters in the soil. While in the soil, the nematodes can get rid of them.

Beneficial nematodes are also effective against borers. This is another pest that overwinters in the soil, and your nematodes will also take care of them.

In the lawn, good nematodes will control grub worms and chinch bugs - two common lawn pests in our area.

Ticks are never fun to have around, especially if you have dogs. Female ticks will feed on an animal until engorged with blood and then drop to the ground to lay about 3,000 eggs at a time. Keep a large population of beneficial nematodes in these areas to help eliminate the tick larvae.

This is just some of the pests that good nematodes help to prevent. I think you get the idea though - beneficial nematodes are something we want to have in our soil.

Until next time, let's try to garden with nature, not against it, and maybe all our weeds will become wildflowers.

Laurie Garretson is a Victoria gardener and nursery owner. Send your gardening questions to or in care of the Advocate, P.O. Box 1518, Victoria, TX 77902.



Powered By AffectDigitalMedia