According to the label, you will 0.73 oz of Quali-Pro Dithiopyr 2EW Pre-Emergent Herbicide per 1000 sq ft or 2 pts per acre. The gallon will cover up to 4 acres.
In general, Quali-Pro Dithiopyr 2EW Pre-Emergent Herbicide and other pre-emergent herbicides should ideally be put down 1-2 weeks before soil temperatures reach 55 degrees consistently.
For the best timing on when to apply Quali-Pro Dithiopyr 2EW Pre-Emergent Herbicide we would recommend contacting your Master Gardener at your local cooperative extension office as they will have information for your specific region. Please be sure to review the product label for more information and complete application instructions before use. Defender Herbicide is a post emergent herbicide best applied when weeds have just started to emerge and can be applied around the same time if listed weeds are actively growing.
The general rule for spring is to apply your pre-emergent herbicide treatment after the ground has thawed from the winter but before the temperature of your soil reaches 55 degrees, as that is when crabgrass begins to germinate. Other weeds will germinate when the soil temperature is between 55 and 65 degrees. You can use a soil thermometer to determine the temperature of your lawn/area. You will want to measure the temperature of the soil a few inches below ground.
The ideal time to apply a fall pre-emergent herbicide to your yard is between August and November when the soil temperature is below 70 degrees and dropping.
Generally, if the Quali-Pro Dithiopyr 2EW Pre-Emergent Herbicide is not stored correctly separation happens. It's like when you have a milkshake & you let it sit for too long.. the ingredients split & you see two layers. If stored correctly and it does split, you just need to shake it back up for them to remix.. but if it doesn't mix back up it wasn't stored correctly or it's too old. The shelf life of our concentrates is 3-5 years.
Yes, Quali-Pro Dithiopyr 2EW Pre-Emergent Herbicide is safe to use on St Augustine turfgrass as directed on the label.
