It’s not possible to eliminate weeds with just one application of weed killer therefore you must set up a ‘management program’ that adjusts to the needs of your property on a seasonal basis.
Pre-Emergent Herbicide is designed to control germinating weed seeds, not to control pre-existing weeds. Meaning that treatment should begin before the weeds emerge from the ground. This is how you start a weed management program and doing this will keep your labor costs down while giving you the best results possible.
This herbicide barrier will kill the weed as soon as it begins to sprout. Remember not all weed seeds will sprout in the same season and a few will sneak thru the barrier which is why a management program is highly suggested.
A management program usually consists of 2 or more herbicide applications per year and with each successful season the need to spray Pre-Emergent Herbicides will lessen.