A selective weed killer is a type of herbicide that kills some plants, while leaving others unharmed. It is frequently used in agriculture and landscaping to eliminate unwanted weeds. While common among landscaping professionals and those who are licensed to use chemical pesticides, selective weed killer for lawns is also manufactured for use on residential properties and many types do not require special certification to use. In fact, selective herbicides are the most widely used form of pesticide, and are the most popular type of weed control.
Selective herbicides are divided into two main categories: organic and chemical. Those made commercially are often expensive and may not be available to the amateur home landscaper. Many, however, are made from ingredients commonly found in the home, such as vinegar, salt, citrus oil and some spices, and although it can be difficult to know what amounts to use, it is possible to make something that is both nontoxic and effective.
Due to their variety and their effectiveness, chemical herbicides remain the most popular. The 2, 4-dichlorophenoxyacetic acid was the first widely used chemical pesticide, and it is still in wide use today, due to its low manufacturing cost. As with many selective herbicides, it targets wide-leaf plants and leaves most grasses unharmed, making it a good option for the home landscaper. Glyphosate is another popular chemical herbicide that has a high level of selectivity.
Herbicides have been criticized for being hazardous to human and animal health, and harmful to the environment. Although many, when used properly, are not dangerous, direct contact with the skin can cause irritation and their consumption can cause sickness or even death. Contact with some herbicides over a long period of time has been shown to contribute to cancer and those that do not decompose quickly may find their way into ground water. That said, selective weed killer for lawns can be an effective option for weed control, so long as they are approached with caution and knowledge.