September through mid to late October is the timeline to apply fall pre-emergent herbicide to your lawn. For what it’s worth, the National Weather Service is predicting a cool and wet fall. With that in mind, pre-emergent herbicides must be active in the environment at the time of germination to be effective. Seeds follow Mother Nature’s schedule and are not concerned with what month it is. Three criteria must be met for seeds to germinate: correct moisture, correct temperature and a good location (soil). When these conditions are met the seed will sprout regardless of month. The first two weeks of September is the ideal time to apply pre-emergent.
The synthetics we carry are Dimension and Gallery. Dimension targets the grassy weed like the annual bluegrass. Dimension can be applied every 4 to 6 weeks. Gallery targets the broad leaf weeds like henbit and is applied once a season.
The all-natural solution is corn gluten meal. It is available in powder and granulated forms. The powder works faster than the granulated corn meal but is a mess to apply. I recommend applying corn gluten meal 2 times about 6 weeks apart.
Everyone should apply fertilizer this time of year. If you are using an all-natural fertilizer now is the time. For the synthetic folks, I would wait until the temperature drops into the lower 90’S. As always read and follow the label directions.