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Lawn Problems

Lawn Pesticides

When maintaining a landscape, whether lawns or ground covers, there may come a time when you need some sort of pesticide. It's wise to understand some basics about pesticides, as well as some common sense tips for pesticide safety.

Pesticides are chemicals that are used to control pests. They include insecticides, herbicides, fungicides, and others. For a pesticide to be effective, it must interfere with the normal development of the pest without doing harm to the host. This does not mean all pests will be eliminated. In fact, your pest problem might not be severe enough to warrant the use of a chemical. For instance, a few dandelions in the lawn can easily be removed by hand.

Dandelions are a common problem throughout the United States.
Dandelions are a common problem throughout the United States.

One should only use pesticides as a last resort. Wherever possible, use organic pesticides. One possibility is pesticides containing Bacillus thuringiensis (Bt), a bacteria that kills some pests but is not toxic to other animals or plants. If absolutely necessary, use toxic chemicals with the greatest care.

Pesticide safety when handling, mixing, applying, and storing the chemicals is critical. Most poisoning occurs during the mixing process. Splashing concentrated chemical on the skin or in the eyes, for instance, can be prevented by wearing long sleeves and trousers, rubber gloves, and safety goggles.

Pesticides must be stored in their original containers; never store a diluted solution in a bottle or jar. And, of course, keep all pesticides out of the reach of children. Read the pesticide label and follow the directions each time the pesticide is used. Follow the directions precisely; the proper dose and calibrations have already been scientifically calculated for the most effective use.

Insecticides are pesticides that are used to control insect pests. You'll first need to accurately identify the pest because not all insects can be controlled with one insecticide.

Insect damage is done by insects that chew leaves and roots and by insects that pierce the plant and suck sap from the plant. Insecticides that control root-feeding insects may be applied as granules with a lawn spreader or with a sprayer in liquid form. Either way, it is important to wash the chemical into the soil and prevent children and pets and wildlife from resting on the lawn for the safety period specified on the pesticide label.

Top-feeding insects, which feed on the leaves of ground covers and turf, are best controlled by spraying the pesticide and allowing it to dry on the foliage. The pesticide's effectiveness is lost if it is washed off by rain or irrigation.

Herbicides -- pesticides that control weeds -- are chemicals you'll potentially use on your lawn and, to a lesser degree, in beds of newly planted ground covers. Weeds are divided into two main categories. Perennials, which may be broad-leaf or grassy, live for many years. Annuals, either broad-leaf or grassy, live for only one season and reseed.

Preemergent herbicides are used to prevent the germination of many weed species, mostly annuals. They are often used early in the spring to prevent weeds, such as crabgrass, from germinating in late spring.

Postemergent herbicides are directly applied to newly germinated or established weeds. Broad-leaf weeds and perennial grasses are most often treated with a postemergent herbicide. Postemergent herbicides are classified as either a contact herbicide, which kills the part of the plant that it comes in contact with, or a systemic herbicide, which translocates throughout the entire plant. Systemic herbicides are most effective for perennial weeds.

Herbicides are also grouped as selective or nonselective. A selective herbicide controls one category of plants (for instance, broad-leaf weeds but not grasses). Nonselective herbicides kill any green plant the chemical comes in contact with. Nonselective herbicides are useful for controlling weeds in paths, driveways, and patios.

Be aware, however, that the slightest breeze may cause the chemical to drift to nearby ornamental plants, causing damage or death to those plants. When using a nonselective herbicide, keep the spray nozzle close to the weeds and never apply during breezy or windy weather. The goal is to control the weeds while minimizing damage to non-target ornamentals and turf.

As you can see from the suggestions outlined in this article, establishing a healthy lawn is relatively simple if you follow some basic guidelines during planting and are sure to keep pests at bay. Keep reading to learn how to identify weeds and pests.

On the next page, you'll learn about lawn weeds.

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