What is the best strategy for controlling dandelions in late July?

Using a postemergence herbicide is the best strategy for controlling dandelions in late July because this timing aligns with the growth cycle of the plant. Dandelions are typically active during this period, making them vulnerable to herbicides that target established weeds. These postemergence herbicides are designed to be applied directly to the foliage of the weeds, allowing for absorption and effective control of the dandelion population.

In contrast, applying a preemergent herbicide would be ineffective at this time, as preemergent products are intended to prevent weed seeds from germinating and are most effective when applied before the weeds emerge in the spring. Additionally, simply watering the lawn frequently won't control established dandelions; rather, it may help promote the growth of both desirable and undesirable plants. Increasing mowing frequency can help manage dandelions to some extent by preventing them from flowering and producing seeds, but it won't eradicate the existing plants. Therefore, using a postemergence herbicide is the most effective approach for controlling dandelions at this stage.