Ask Burton: Q: I hear that using a pre-emergent herbicide will help me to keep weeds from coming up in my lawn grass during the fall and winter. What do you recommend and when should I apply it?

A: To head off weed issues while they’re still a non-issue, late August is the time to start applying pre-emergent herbicide!

The best time to apply pre-emergent for the fall season runs from the last week of August through the first two weeks of September. Apply Dimension herbicide to prevent grassy weeds like annual bluegrass and crabgrass, and Gallery to stop all of our most troublesome broad leafed weeds from popping up all through the cool season – and you can apply both of these products on the same day.

Our 35 lb bag of Dimension will cover 7,500 square feet at the Southern lawn listed rate on the bag, and our 10 lb bag of Gallery will cover 2,000 square feet per bag. If you know your lawn size accurately, that’s ideal! If you don’t know,  I can tell you that our customers in town often need most of a bag of Dimension, and between 2 to 3 bags of Gallery to cover their lawns. Calculate it as accurately as you can and use common sense adjustments if you have a large swimming pool or other reason your turf area is a different size, (such as a larger than normal lot or a zero lot line home.)

Do water in your pre-emergent herbicide in a controlled fashion, rather than depending upon rainfall, whenever possible. Rain tends to come in the flavors of “too much!” and “not enough!”, and your valuable herbicide does no good washing off your lawn into the storm drains.

Burton specializes in diagnosing and solving plant problems. If you have a question for Burton, please email him at and include photos showing the problem.