Common Weeds Classification

Common weeds classification includes sorting by life cycle and physical characteristics.

Life Cycle

Different weeds have different life cycles. They are classified as annual, biennial, and perennial.

1. 1. Annual - Of a single year duration. They grow, produce seed, and die in one season. The seeds from the plant germinate and grow the next year, continuing the cycle. Examples of annual weeds are crabgrass, foxtail, common chickweed, and annual bluegrass. These annual weeds must be killed before they begin growing from seed.
2. Biennial - Of 2 years duration. They generally only form leaves the first year and produce flowers and seeds the second year. Some biennial plants grow through rhizomes and stolens instead of seeds, so you have to be sure to kill the entire plant to control these weeds. Examples of biennial weeds are the bull thistle, burdock, and mallow.
3. Perennial - Of more than 2 years duration; reoccurring year after year. They may go dormant for part of the season, but they will come back. These stubborn weeds can endure indefinitely if left unchecked. Since they too can grow through rhizomes and stolens, be sure to kill the entire plant to control these weeds. Examples of perennial weeds are the dandelion, quackgrass, and white clover.

Physical Traits

The physical characteristics of common weeds classification includes grasses, broadleaves, and sedges.

1. Grasses. Narrowleaf or grassy weeds look and act like grass. The leaves are narrow, stand upright, and have parallel veins. When the seedlings sprout, they have only one leaf. Grasses grow from a point located below the soil surface, thus the growing point is sheltered. This is why grass can be mowed without killing the plant. Most grasses have fibrous root systems. Grasses have both annual and perennial species. Examples include annual bluegrass, crabgrass, and Bermuda grass (this is considered a weed in areas where it was not intentionally planted).
2. Broadleaves. Broadleaf weeds are any weeds that don't look and act like grass. Seedlings of broadleaves have two leaves that emerge from the seed. The veins of their leaves are netlike. They usually have a taproot and their root system is relatively coarse. All broadleaf plants have exposed growing points that are at the end of each stem and in each leaf axil. They may also have growing points on roots and stems above and below the surface of the soil. Broadleaves may be annual, biennial, or perennial. Examples include dandelions, clover, and chickweed.
3. Sedges. These are similar to grasses, but they have triangular stems and 3 rows of leaves. They are sometimes listed as grasses on the pesticide label. Sedges are often found in wet places, but are pests in fertile, well drained soils. Examples include yellow and purple nutsedge.