Ever wonder what those pesky little weeds are in your lawn? Weeds, like all plants, require certain elements such as light, water, oxygen, carbon, etc. to grow, but some species can actually thrive where other plants may not. Weeds come in many different shapes and sizes, life cycles, growth habits, and more. Also, don’t forget that “weeds” are in the eye of the beholder. What one person considers a weed, another person may consider desirable. Weeds with colorful or showy flowers can attract pollinators, while weeds with spreading growth habits can hold disturbed soil in place where growth of other plants may be restricted. A dense healthy lawn is the best defense against common lawn weeds, but even the nicest lawns often have a few in them so don’t beat yourself up!
Consult the gallery of common lawn weeds below to learn more!
Weed Life Cycles
Weeds can be annuals, perennials, or biennials. Winter annual weeds germinate in the fall, grow throughout the winter and spring, and die with the summer heat. Biennials take two years to complete their life cycle while perennials such as Virginia buttonweed, sedges, and others live for more than two years, often indefinitely. Life cycles are important to understand because many products labeled as pre-emergence herbicides are only effective when applied prior to germination of annual weeds (crabgrass, annual bluegrass, chickweed, many others). These products often have several weeks or months of efficacy and will control germination of weeds throughout that time. Products labeled as post-emergence herbicides can be applied to weeds after germination and typically have a much shorter residual window of control. Consult the product label for more information on timing and application.
Types of Weeds
Weeds are often categorized into broadleaf weeds, sedges, or grassy weeds for control recommendations. This is because many herbicides that are effective on one type or not effective on other types. However, there are products available that will control various types of weeds, so consult the product label for information on specific weeds. Generally speaking, broadleaf weeds have netted leaf veins, various leaf shapes and arrangements, and highly variable flowers that are often colorful and showy. Sedges and grasses have narrow, linear-shaped leaves with parallel veins, and as a result they can often be confused with each other. They do have distinguishing features in their stems and flowers that make them easy to identify. Grasses have hollow stems that can be round or flattened and sedges have solid, pith-filled stems that are triangular in shape.
