Herbicide Guide

Pre-emergent Herbicides

• Pre-emergent herbicides are frequently the herbicide of choice for lawn care applications. Pre-emergent herbicides don't kill vegetation. Instead they prevent the seeds of undesirable plants from growing. Since the seeds of some weeds may remain viable up to 50 years, a pre-emergent herbicide must be reapplied yearly.

Selective Herbicides

• Selective herbicides are used in lawn care or around nursery or garden plants once weeds emerge. A selective herbicide is used to kill weeds, but does not kill the valuable plant. Some selective herbicides facilitate this by using chemicals that resemble plant hormones. The weeds respond to the hormone, while the desirable plants do not. Other herbicides are classified as selective herbicides because they must be applied directly to the weed in order to be effective.

Unselective Herbicides

• Unselective herbicides are the herbicide of choice for people who want to kill all vegetation in an area. These types of herbicides are generally used in building projects, near fences and within industrial complexes. Because they kill all plant life and leech nutrients from the soil, these herbicides are also known as soil sterilizers. Chemical poisons and toxic substances are both considered to be unselective herbicides. More natural compounds, such as clove oil, vinegar and citric acid have been used in unselective herbicides. However the vinegar and citric acid in these herbicides are of a higher acidic content than common household versions.