The seeds of broadleaf weeds are naturally occurring in all soils. Some can persist for as long as 30 years if not properly eradicated and can turn an otherwise beautiful lawn into an eyesore. Broadleaf weeds, which are typically easy to spot in turf, can produce thousands of seeds per plant throughout its life cycle, and these seeds are capable of spreading over several miles. Controlling broadleaf weeds is essential to achieve a luscious, healthy turf, and is generally easier than controlling grassy weeds.
Differences Between Broadleaf Weeds and Grassy Weeds
Plants are divided into two major groups: monocotyledons (monocots) and dicotyledons (dicots). Monocots are flowering plants that have seeds that contain one embryonic leaf, or cotyledon. Dicots, on the other hand, are also flowering plants, but their seeds contain two cotyledons. Grassy weeds are considered monocots, which makes them more biologically similar to the grasses we grow in our lawns and landscapes. This makes grassy weeds more difficult to control than broadleaf weeds as herbicides are either broad-spectrum, which kills all growth, or selective, which eradicate certain broadleaf or grassy weeds. Broadleaf weeds have several ways of reproducing: seeds, clumping, running, cuttings, tubers, and root division are just a few of the ways broadleaf plants can spread throughout a lawn. Grassy weeds, on the other hand, typically only spread through clumping and running.
Controlling Broadleaf Weeds
Because broadleaf weeds are not as biologically similar to grass as grassy weeds and sedges, they are easier to control. There are several approaches to keeping these types of invasive plants at bay, and they consist of cultural and chemical measures. Both methods require due diligence as well as year-round attention to the turf to keep these plants at bay.
Cultural Control of Broadleaf Weeds
Cultural control methods involve maintaining a healthy lawn. When weeds appear, it may be an indication of poor growing conditions. The first step to eliminating weeds in turf is to review your lawn care practices and make adjustments as needed to promote a healthy and vigorous lawn that is resilient and resistant to weeds. When grass is strong and healthy, it is able to prevent and compete with invasive and unwanted weeds. Cultural control should include proper selection and establishment of turf, fertilization, watering, mowing, and thatch management. Removing leaves, acorns, fallen fruit, or other organic materials (or any materials) that cover any portions of grass and allow for shady or damp conditions should also be considered to avoid disease. Poor soil conditions, over-watering, improper fertilizing, soil compaction, and disease can make it easier for unwanted vegetation to take root and overrun your landscape.
Chemical Control of Broadleaf Weeds
Pulling weeds by hand is undoubtedly an acceptable means of eliminating them from your outdoor space. When removing weeds manually, it is essential to remove as much of the root as possible to prevent re-emergence. Manually pulling them is a labor-intensive and time-consuming process, however. Therefore chemical control measures are often a better choice for eliminating unwanted herbaceous growth. Herbicides can cover a broad range of weed species and provide a much more effective result.
As the name suggests, pre-emergent herbicides work by killing weeds before they sprout from the ground. While they don’t stop weed germination, they stunt the growth process of the plant before it emerges from the soil. With pre-emergent herbicides, timing is crucial to achieve the best result. Applications should be made before the weed seeds start germinating. However, applying them too early can make them completely ineffective. Weed germination begins once the soil has reached a specific temperature. The best way to time applications of pre-emergent herbicides is to contact local extension offices or master gardeners who have access to regional soil temperature data. When using pre-emergent weed killers, it is important to treat the entire lawn, and most of these treatments need to be watered into the ground to reach the seeds beneath the soil.
Post-Emergent Herbicides target weeds that have already made an appearance. Once a weed has already matured, however, multiple applications may be required to eliminate them. These herbicides are most effective on young, actively growing weeds. Additionally, an excellent time to apply post-emergent herbicides is early to mid-fall. Not only does this decrease the chances of lawn injury from the application, but weeds are naturally dying off and going into winter dormancy at this time. These plants are storing energy for the winter in their stems and roots at this time of year. Post-emergent herbicide applications at this time will carry the chemical into the food and energy stores of the plant and give a complete kill of the weed.
A Year-Round Endeavor
A lot of people think that caring for their lawns is only a summer chore. The truth is, maintaining healthy turf requires year-round diligence–especially when it comes to weed control. The healthier the landscape, the less likely weeds are to invade the outdoor space. Proper cultural measures to prevent weeds require attention through all four seasons–not just through spring and summer. The result is a gorgeous lawn that is thick, vigorous, healthy, and above all–weed-free.