Anyone who has a lawn—or has even seen a lawn—knows that weeds are an inevitable issue. There are many ways to treat and eliminate weeds, but one commonly misunderstood method is the use of herbicides.

The most important part of herbicide use is understanding and following label directions – the label is the law when using these chemicals. When used properly, these products can control or eliminate weeds and be safe for other plants, animals and humans. Herbicides often get a bad rap, but most of the time, it is because it is used excessively or improperly. Below are some herbicide basics. Use these to inform your decisions in combination with label instruction and professional guidance.

Pre-emergence vs. Post-emergence. This is an indication of whether a plant should be treated before the plant has germinated (pre-emergence) or after germination, when the plant has foliage (post-emergence).

Contact, Systemic, Selective or Nonselective. These categorizations are used to describe the mode of action of the herbicide. Contact indicates that it controls only the portion of the plant to which the product is applied. Systemic means the product is moved within the plant’s vascular system to affect the entire plant. Selective herbicides kill or damage certain plant species without harming others. Nonselective herbicides kill or injure all plants.

Active Ingredients, chemical names and trade names.  The active ingredient is the chemical contained in the product that controls weeds. Chemical names are the complex active ingredients listed on the label. Trade names are what manufacturers use to market those chemicals.

The herbicide bottom line is that it is essential to understand the type of grass you have, the weed(s) you want to control, and which herbicide is appropriate. THEN you can use that product as indicated on the label alongside proper cultural practices.