The definition of a weed is a plant in an undesirable area. The majority of lawn weeds reproduce by dropping seeds. There are tens of thousands of weed seeds in your lawn soil and under the right conditions they will germinate. Typical weeds in the lawn are broken down into many different categories and have different life cycles making them a continual challenge to control. There are broadleaf weeds, grassy weeds, perennial weeds and annual weeds. Additionally, there are sedges and undesirable grasses that are difficult to control/eliminate. Annual weeds are broken down into cool season weeds and warm season weeds. Chickweed and Henbit are typical cool season annual weeds that germinate often during the fall seeding season and continue to germinate through the spring. When we treat these weeds in April they will die out; however, in the month of May you might see new weeds begin to germinate. These are often the start of warm season broadleaf weeds such as Lespedeza and Black Medic. These weeds don’t all germinate at once and will continue to germinate and develop throughout the summer. The number one annual grassy weed with which almost everyone is familiar is crabgrass.
Crabgrass will begin to germinate in late April and continue to germinate throughout the summer. Applying two applications of crabgrass pre-emergent is the best way to get a handle on controlling this aggressive weed. Anyone with a vegetable garden understands the persistence of these weeds as mechanical removal of newly emerging weeds is an ongoing chore. Weed seeds like to germinate best in bare soil when they receive enough sunlight and water. The best way to keep weeds from spreading is by having a thick stand of turf, maintaining the proper mowing height and employing proper watering practices. I will continue to write about certain weeds during the growing seasons. Stay tuned.