Lawn care tips from local expert, Zac Reicher
Professor/Turfgrass Extension Specialist, Purdue University
Springtime Dandelion Control Still Not as Effective as Fall Control
When the annual bloom of dandelions occurs in central Indiana, it marks the beginning of the second most effective period for controlling broadleaf weeds. The optimum time to control dandelions and other broadleaf weeds is in the fall and the second most effective time is in late spring, at or shortly after the flush of flowers. If only a few dandelions are present in the turf, consider spot-applying a herbicide rather than treating the whole lawn. It’s ineffective to use more herbicides than what is necessary on turf. Be extremely careful when applying any herbicides near ornamentals, because they can be easily damaged by these herbicides.
Choose Pre-emergence Herbicides with as Little Nitrogen (N) as Possible
Look for a product with low nitrogen and be sure the majority of the nitrogen is a slow release N. These are listed on the label as “slowly water soluble” or “water insoluble.” Applying too much fertilizer now will encourage too much growth and could lead to problems later this summer such as poor root growth and disease. Additionally, since spring rains play havoc with mowing schedules, nitrogen fertilization can further complicate your mowing schedule by causing grass plants to grow too fast.
Pre-emergence Control of Crabgrass
April 15-20 usually marks the end of the window for applying traditional pre-emergence herbicides in central Indiana, a week earlier in southern Indiana, and a week later in northern Indiana. Though most pre-emergence herbicides do have minor post-emergence properties that will burn back small crabgrass (one or two leaf stage), this is not always reliable.