The answer to 'lawn fertilization has weeds' is that fertilizing your lawn can sometimes lead to an increase in weed growth. This is because the fertilizer provides nutrients that can also benefit weeds, causing them to thrive alongside your desired grass.
Common causes of weeds after fertilizing include applying too much fertilizer, using the wrong type of fertilizer, or not properly preparing the lawn before fertilizing. Symptoms may include an abundance of broadleaf weeds, grassy weeds, or other unwanted plants in the lawn. To solve this issue, you may need to adjust your fertilization schedule, apply targeted weed control treatments, or overseed with grass seed to outcompete the weeds.