Every year, many people stop by the N.C. Cooperative Extension, Sampson County Center with a plant sample in hand and a familiar question: “Is this a weed?” The answer is rarely as simple as yes or no.

A weed is generally defined as “a plant out of place.” NC State University Extension expands that definition by describing weeds as plants that interfere with the intended use of a landscape, crop, or managed area. A plant may be considered desirable in one setting but a nuisance in another. Bermudagrass is a great example. In a sunny home lawn or athletic field, bermudagrass is a durable, attractive turf choice for our region. But when it spreads into flower beds or vegetable gardens, that same grass becomes a problem—an aggressive invader that competes for nutrients, sunlight, and water.

The Many Kinds of Weeds

There are thousands of plants that qualify as weeds in North Carolina lawns, gardens, and flower beds. They are classified in several ways:

• By life cycle
  • Annuals complete their life cycle in one year, such as crabgrass or chickweed.
  • Biennials grow for two years, often forming leaves the first year and flowering the second, like wild carrot (Queen Anne’s lace).
  • Perennials live for multiple years and are the most difficult to control because they reproduce by both seed and underground structures such as rhizomes and tubers. Examples include nutsedge, dallisgrass, and Virginia buttonweed.
• By plant type
  • Grassy weeds resemble turfgrass species with narrow leaves and parallel veins—examples include crabgrass and bahiagrass.
  • Broadleaf weeds have wider leaves with net-like veins, such as dandelion, henbit, or clover.
• By growing season
  • Winter weeds germinate in fall, grow through winter, and mature in spring.
  • Summer weeds sprout in spring and grow through the warm season.

Fall Weed Management

Fall is one of the most important times of year for weed control. The steps you take now directly affect how many weeds you’ll see in the spring. According to NC State Extension’s TurfFiles, early fall is ideal for applying preemergence herbicides that target winter annual weeds before they germinate.

Winter weeds such as chickweed, annual bluegrass (Poa annua), wild garlic, Carolina geranium, henbit, and several clover species begin sprouting from seed as soil temperatures drop into the 50s. These weeds grow slowly during winter, then surge in early spring, often forming dense mats that shade and thin desirable turf.

Timing and Product Selection

For most of eastern North Carolina, the first preemergence herbicide application should be made in September, when soil temperatures consistently drop below 70°F. A second application around late November or early December helps catch any late-germinating seeds.

Products containing benefin, pendimethalin, prodiamine, or dithiopyr are effective for most annual grassy and broadleaf weeds. These products create a barrier at or near the soil surface that prevents weed seeds from sprouting. Always read and follow label directions, especially regarding turf type, reseeding intervals, and application rates.

To activate the herbicide, water the treated area within 24 to 48 hours of application with about a half inch of irrigation or rainfall. Skipping this step is one of the most common reasons preemergence herbicides fail to perform.

Good Cultural Practices Matter

Chemical control works best when combined with good cultural practices. Keep your lawn healthy by mowing at the proper height for your grass type, fertilizing based on soil test recommendations, and watering deeply but infrequently. A dense, vigorous lawn shades the soil surface and naturally suppresses weed germination.

In garden and flower bed areas, mulch plays a similar role. A two- to three-inch layer of pine straw, bark, or composted mulch helps reduce weed seed germination while improving soil moisture retention and temperature regulation.

When in Doubt, Ask for Help

If you’re unsure about a plant or the best control method, bring a sample to the Sampson County Cooperative Extension Office. Extension agents can help identify the weed, explain its growth habit, and suggest the most effective management strategy for your situation. With proper timing and care this fall, you can enjoy a cleaner, healthier landscape next spring.