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weed killer or grass seed first

Fertilizers containing pre-emergent herbicides selectively prevent certain kinds of weeds from finishing their germination cycle. There is no point applying this type of weed-and-feed mix after weeds are growing on your lawn. You have to apply it early in the growing season before weeds appear. Make sure the pre-emergent herbicide in the fertilizer kills the kind of weeds that have plagued your lawn in the past. You might apply a starter fertilizer containing a pre-emergent herbicide before you sow your lawn seeds.

Post emergent herbicides kill weeds after they appear. Some post-emergent, systemic herbicides that you can apply directly on lawns only kill weedy grasses, while others only kill weeds with broadleaf weeds. Contact herbicide such as those including the active ingredient glyphosate kills on contact. To use one of those on a lawn without killing the grass you have to daub it on individual weeds.

You can sow grass seeds now and kill weeds later with a post-emergent herbicide or kill weeds now with a pre-emergent herbicide and plant the seeds later. Weed-and-feed fertilizers are specially formulated combinations of turf fertilizer and herbicides that you apply either before you plant grass seeds or on established lawns.

Pre-Emergent Weed-and-Feed Fertilizer

You apply pre-emergent herbicides before weed seeds germinate, typically in the spring. Pre-emergent herbicides do not prevent weed seeds from germinating; they suppress the development of weed roots as they germinate. They’re usually effective for two weeks to three months, depending on the formulation, and you have to water the lawn after applying for the herbicide for it to be effective. There are pre-emergent herbicides to kill both broadleaf weeds and weedy grasses. You can apply them before you sow your grass seed. If you apply a pre-emergent herbicide that kills weedy grasses, you have to delay sowing your lawn seed.

Post-emergent weed-and-feed formulations kill selective weeds that are already growing in your lawn. Make sure that the herbicide in the formulation you buy kills the type of weeds that are growing in your lawn. Most weeds make their appearance in the spring, the best time to apply weed-and-feed fertilizer.

This depends on the time of year. Weeds tend to really thrive and spread during the middle of summer. The middle of summer is also the worst time to plant grass seed.

If you do see any weeds pop up in the grass seed area, pull them right away! Don’t use a weed killer quite yet. Your new grass can’t handle an herbicide at this stage.

How can I prevent weeds when planting grass?

We’ve all heard the saying, “An ounce of prevention is worth a pound of cure!” This is true of weeds, as well. There are several easy ways to prevent weeds when planting grass.

You may have a few weeds. It happens to everyone. Will grass seed still be able to thrive and grow amidst a few weeds?

Look for a reputable brand of grass seed. It should list “weed seeds 0%” and “other crop seeds 0%”.