15 of the worst offenders and how to control them

Some of the most common and hard-to-control garden weeds are profiled here. For each, we first suggest nonchemical controls. Appropriate chemical controls are also noted; these may include pre-emergence herbicides, post-emergence products, or both. Before using any chemical control, always check the label to make sure the product is safe for any desirable plants growing in or near the area to be treated.