6 Reasons Why Weeds Grow in Your Lawn (2024)

If your lawn looks like a jungle with weeds popping up all over, there’s probably a reason why. Mowing mishaps, improper watering, poor soil health, pests and diseases, compacted soil, and too much shade can give weeds the perfect opportunity to thrive. Learn more about the top 6 reasons why your lawn might be sending an invitation to weeds.

Reasons for Weeds to Grow in Your Grass

These are six common reasons weeds grow faster than grass in your lawn.

1. Bad Soil Health

Weeds love unbalanced soil and will fill in the gaps where your grass struggles. When the soil is missing essential nutrients or has an off-balance pH, weeds are ready to take control. Weeds prefer acidic soil, which means a pH that ranks below 7.

Pro Tip: To get a clear picture of what your soil needs, perform a soil test. If your soil lacks nutrients, soil amendments and fertilization are the key. But be careful! Fertilize only during your grass type’s growing season. Otherwise, you’ll end up feeding weeds instead of your lawn.

2. Compacted Soil

Compacted soil is another reason your lawn ends up covered by weeds. Compacted soil is like a dance floor at a crowded party: everything is squished together, leaving no room for grass roots to spread out and grow. While your grass is struggling to breathe, weeds are partying it up, having adapted to thrive in cramped conditions.

Pro Tip: The solution? Lawn aeration! Prepare your lawn for aeration and create space for air, water, and nutrients to reach the grass roots so healthy grass can grow and outcompete weeds.

3. Diseases and Pests

When your grass is thin and struggling because of diseases and pests, weeds see their chance to swoop in and take over.

Common lawn diseases like brown patch or dollar spot can cause your grass to die. Meanwhile, pests like grubs and chinch bugs munch on your lawn, leaving it weak and vulnerable. This leaves weeds ready to move in and take over those bare spots.

Pro Tip: To keep your lawn strong, stay vigilant against diseases and pests. With the right treatments, your grass can fend off these invaders and keep weeds at bay.

4. Improper Watering

Your lawn needs just the right amount of water to look its best. Under water your lawn and it will struggle to grow, opening the door for weeds to swoop in. Drought conditions can have a similar effect. Overwater it, or let drainage issues create a swampy mess, and your grass will suffer while some weeds thrive like they’re at a pool party.

Weeds that grow in dry environments:

• Black medic
• Common yarrow
• Crabgrass
• Prostrate spurge
• Red sorrel

Weeds that grow in wet environments:

• Common chickweed
• Curled dock
• Dandelion
• Ground ivy
• Purslane
• Yellow nutsedge

Pro tip: To keep your lawn in good shape, make sure it gets about an inch of water each week during its active growing season. Here’s a guide on “How Often Should I Water My Lawn?“.

5. Mowing Mistakes

Improper mowing is a major reason why weeds take over your lawn. When you mow your grass too short or scalp the edges around hardscaping, you create an inviting environment for weeds. Weeds thrive in the thinned-out areas of your lawn, where they can soak up plenty of sunlight.

It is also important to mow at the recommended height for your grass type and make sure the mower blade is sharp to cut cleanly.

Here are some guides on proper mowing:

• “Lawn Mowing Tips: How to Mow a Lawn the Right Way”
• “How to Prevent Grass Clumping When Mowing”
• “Mowing Height Debate: Last Mow of the Season Low?”
• “When to Stop Mowing the Lawn Before Winter”

6. Shady Areas

Most turfgrass species need at least 6 hours of direct sunlight to grow well. If your lawn isn’t getting enough sunlight, it’s not going to thrive. Meanwhile, plenty of weeds have adapted to shady conditions and will happily take over dimly lit spots.

Weeds that grow in shady areas:

• Ground ivy
• Poison ivy
• Quackgrass
• Wild violet

Trimming or cutting back trees to increase sunlight can help. But if you love your shady areas and don’t want to part with your trees, there are alternative solutions. Try adding flower beds with shade-loving plants, hardscaping, or extending tree mulch rings.

You can also consider planting shade-friendly turf options like fine fescue varieties or shade-tolerant groundcovers such as wild ginger or mondo grass.

FAQ About Why Weeds Grow in Your Lawn

What are the best weed killers on the market?

The best weed killers on the market are:

• Ortho WeedClear Lawn Weed Killer for Northern Lawns
• Ortho WeedClear Lawn Weed Killer for Southern Lawns

How can I tell if I touched a poisonous weed?

If you suspect you’ve touched a poisonous weed, watch for signs or symptoms on your skin. Within a few days of contact, you might notice a red rash, bumps, red patches or streaks, or even weeping blisters.

How can I make a natural remedy to kill weeds on my lawn?

You can make a homemade weed killer by mixing 1 cup of salt, 1 tablespoon of liquid soap, and 1 gallon of vinegar.

When to Hire a Professional

Having a beautiful lawn means keeping a watchful eye on weeds that are always ready to appear. By understanding why weeds invade your lawn, you can take steps to avoid or get rid of them before they take over.

If it ever feels like taking care of your lawn is too much, call a lawn care professional to help you with the job. With a little vigilance and the right help, you can keep your lawn looking amazing!

Main Photo Credit: Mike Mozart / Flickr / CC BY 2.0