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will lawn fertilizer make weeds grow

But here’s the problem: Early spring probably isn’t the best time for you to fertilize your grass or apply herbicides unless you have a history of weed problems.

Trouble is, this assumes that you’ve got weed seeds in your soil ready to sprout. If you’ve been using pre-emergent herbicides regularly or otherwise doing a good job of controlling weeds and keeping them from going to seed, you may have exhausted the supply of weed seeds in the soil. If that’s the case, applying pre-emergent herbicides is like clapping your hands to keep the lions away.

Editors note: Rossi is a turf specialist and associate professor in the Department of Horticulture, Cornell University. This is the first in a series where Rossi debunks common lawn myths. His advice targets cool-season grass growing regions in the Northeast, but may be applicable in regions with similar growing conditions.

Then there’s the fertilizer. It should be mostly nitrogen, and I’ll admit that it can really green up the grass in a hurry. But it can also fuel lush top growth at the expense of roots, and you want those roots going deep for moisture so the grass can outcompete weeds during the hot, dry summer months to come. That lush top growth also means you’ll need to mow more often and deal with more clippings.

Will lawn fertilizer make weeds grow

Lawn fertilizers are engineered with the nutrients essential for grass root and blade growth. By applying fertilizer to your entire lawn, you encourage grass to grow thicker and faster. Fertilized grass will also reclaim bare patches in your lawn. A thick, healthy, well-fertilized lawn forms a carpet. Any weed seeds that try to sprout in thick grass will struggle to take root and are likely to die.

Standard fertilizer does not kill weeds. It provides nutrients to the soil that can be taken up by any plant growing in your yard, including weeds. However, if you kill weeds before you fertilize your lawn, your grass will grow thicker and healthier, discouraging new weeds from invading. Additionally, by adding nitrogen to the soil via fertilizer, you make soil conditions less inviting to many types of weeds. If you want to kill weeds and fertilize your lawn at the same time, you can use a Weed and Feed fertilizer.

Make sure to use the right weed killer to control the types of weeds on your lawn. A broadleaf weed killer will work to control non-grassy weeds, but crabgrass, sedge, and other grassy weeds require specialized weed control products.

Encourages Thick Grass Growth

If your lawn is plagued with spring dandelions and crabgrass that appear while your turf grass is still brown, it’s likely because your lawn lacks fertilizer. If your lawn turns green quickly in spring, it can help smother weeds and eliminate notorious spring annual weeds.

Fertilizer isn’t made of dangerous chemicals. The nutrients in fertilizer naturally occur in soil. However, if your lawn is left unfertilized, nutrients will be gradually pulled from the soil by plants and water runoff. Fertilizing is your way of giving back to the soil and ensuring good grass growth moving forward.

Kill Weeds Before You Fertilize

When applying nitrogen fertilizer, be cautious—too much nitrogen too fast can damage your lawn. Consult product label rates to find the correct amount of fertilizer to be spread per square foot of lawn. Additionally, it’s beneficial to follow a hybrid lawn fertilizer schedule that includes gentle fertilizers.

Once you have killed the weeds in your lawn, it’s time to keep them out with fertilizer. Although fertilizer won’t wipe out weeds on its own, it can prevent weeds from returning. With the right fertilizer program, you can grow a healthy lawn that remains weed-free on its own. This way, you won’t have to battle the same weeds year after year.