Weed Wackers vs. Weed Killers

Weed Management

• Weedwackers do not kill or eliminate weed growth, however, they can help to suppress weed growth and keep weeds from spreading. Chemical weed killers, or herbicides, are capable of killing weeds, but that doesn't always mean the weeds will not later sprout from their roots or seeds stored in the soil. Chemical weed killers usually require repeated applications to eradicate a weed species from the property.

Uses

• Weedwackers are used much like a lawnmower in places that are inaccessible to mowers -- steep slopes or rocky, uneven terrain, for example. Large gas-powered weedwackers are also capable of cutting extremely dense vegetation including the stems of woody plants that would have difficulty passing through a lawnmower. Thus, they don't make the weeds disappear entirely, but they do improve their appearance and discourage reproducing. For example, using a weedwacker before a group of weeds has a chance to flower and seed prevents them from spreading.

Weed Killers

• Chemical weedkillers are designed to kill plant tissues on contact. Some are specifically aimed at broad-leafed weeds, while others target grasses. There are also pre-emergent herbicides that can prevent the germination of weed seeds stored in the soil. Most foliar weed killers are applied as a spray, though pre-emergent herbicides come in a granular form. Herbicides can be used to treat invasive woody plants, like trees and shrubs, which weedwackers cannot. This method usually involves cutting the plant to the ground and applying the herbicide directly to the trunk to keep it from sprouting. Chemical weed control is also the better option to kill weeds growing in cracked pavement.

Disadvantages

• Weed killers have greater potential to harm the environment or human health than weedwackers. Some persist in the soil for long periods and can end up in groundwater supplies. Exposure of humans and animals to some of the chemicals contained in weed killers is known to cause serious health problems. It is important to protect the eyes, skin and lungs when using herbicides and follow all instructions and safety procedures indicated on the label. Weedwackers are not without disadvantages, as well. They are very loud and the gas-powered models emit polluting exhaust. The blades of a weedwacker are also very dangerous -- eye and ear protection, close-toed shoes and protective clothing must be worn at all times.