Last week, I wrote about the frustrating task of weeding the garden and discussed some methods of prevention and management. This week’s column will examine several common garden and lawn weeds and focus on identification.

The never-ending battle for eradication begins as soon as the first weeds appear in the garden in early spring and continues into the fall. The gardener’s first task is to learn to identify the weeds in order not to pull up desired plants by mistake.

Weed identification can be confusing to the novice gardener because some species of certain weeds are planted in garden beds. Yarrow (Achillea spp.), speedwell (Veronica spp.), and vervain (Verbena spp.) are examples of annuals and perennials that can be classified as ornamentals, wildflowers, and herbs, as well as weeds.

Common weed categories include grasses and sedges; broadleaf annual, biennial, and perennial weeds; vining and woody weeds; lawn weeds; and invasive weeds. To complicate matters, weeds also ar...