Perhaps you've moved into a new house and don't know which plants in the flower bed are weeds and which are perennials. Perennials are a valuable asset to any flower bed, but take several years to become established. Once mature, though, they provide care-free blossoms all summer long. Many perennials need little water or fertilizer and thrive with only occasional maintenance. So, before you start pulling plants, identify the perennials and mark them with a garden marker or stick. Come summer, perennials will reward you with their prolific blooms.
Examine your garden in early spring for signs of growth. Many perennials begin growing before weeds emerge. If you notice growth early in the spring, the plant is most likely a perennial.
Examine the entire yard once weeds begin to sprout. If you find the plant in question growing in other areas of your yard, it is probably a weed. If the plant is only growing in the flower bed, it is probably a perennial.
Consult a gardening resource book or online source with good photographs to identify your perennial. Consider the foliage's color, shape, and growing pattern. Look at the flowers. Consider the color and petal pattern. Does the flower bloom alone or in a cluster? What shape are the flowers?
Cut a 4-inch portion of your plant, preferably including a bloom, to a local nursery where a perennial expert can help you identify it.