Among the pests that can plague a garden are tiny little organisms that live in the soil, attacking plant roots and seeds. Not that all creatures that live in the soil are harmful-many of them are essential in fact-but some of them can do plenty of damage when you have a serious infestation. These include such pests as:
* Lesser cornstalk borers
* Mole crickets
* Plant parasitic nematodes
* Seedcorn maggots
What measure works best against these intruders will depend on many factors, including the soil type, the pest, the degree of infestation, and more. But here are some of the actions one can take:
1. Prepare the soil
Almost all soil pests build to large populations on grass roots. If you start a new garden where previously grass was growing, you’re already putting yourself at a disadvantage. To prepare a new area for planting, till or spade thoroughly, and don’t plant until the area has been free of grass for at least thirty days.
2. Keep the soil healthy
The use of compost and fertilizer can make for healthier soil with fewer pests. Keep the area properly watered-not overwatered-as some pests like the lesser cornstalk borer thrive in drought conditions.
3. Alter what you plant and when
Rotating plants can be effective, as the pests that like to feed on one kind of plant will suddenly be confronted with something they have no interest in, and by the time new pests that like the new offering gather in significant number, that plant will have been replaced by something else.
Another thing you can do is learn the life cycle of the particular pest who’s giving you a problem, and then change the time of your planting to take it out of sync with this cycle.
4. Wall off your plants
Pests such as cutworms can sometimes be blocked from your plants by creating sleeves from something like a paper cup with the bottom removed and placing it around the plant with the bottom edge pushed down into the soil.
5. Use baits
Pests such as mole crickets and cutworms can sometimes be controlled with the use of baits. The bait to use and the best time of day to put it out will depend on the pest you are countering.
6. Use predators and parasites
There are “good” insects that eat organisms that attack your plants. There are “good” nematodes, available commercially, that can be especially effective in infecting and killing off pests found in the soil.
7. Plant marigolds
Marigold roots release chemicals that kill bad nematodes. You can plant marigolds, or even till them into the soil and let them decay.
8. Use pesticide
If you’re not going for strictly organic, pesticide-free growing, pesticides such as chlordane can eliminate pests like grubs for years with one application. But strictly follow the directions when using any pesticide, or you could also kill off “good” bugs, or build up insecticides in your soil that could be dangerous to higher animals and humans.
9. Solarize your soil
When soil pests are really out of control, one way to basically wipe the slate clean and start all over is to solarize the soil by raising its temperature to 150 degrees to kill off the disease-bearing nematodes and other intruders.
In the hottest part of the summer, dig up all plants and till the soil to a depth of 12 inches. Remove rocks, twigs, and other debris. Keep the soil moist but not soggy to a depth of two feet. Cover the plot with a sheet of clear plastic, kept in place with soil or rocks around the perimeter. Leave it covered like that for three to four weeks. If you’re in an area that does not get very hot in the summer, you may need to use a second layer of plastic, and leave the area covered for double to triple this amount of time.
Using a combination of these methods should keep any soil pest problems in check.
Vern Grubinger, “Nematodes for Insect Control.” University of Vermont Extension.
Betty Barr Mackey, “How to Prevent Garden Pests and Diseases.” TLC.
Susan E. Webb and Freddie S. Johnson, “Insect Management in the Home Garden.” University of Florida/IFAS Extension.
“Harmful Soil Insects and Other Pests.” Garden Soil.
“How to Rid Soil of Pests and Disease.” eHow.