How to Identify Lawn Problems ASAP—Before Pests or Grass Diseases Take Over

The amount of care, attention, and money that goes into keeping a beautiful lawn isn’t small, so when things start to go sideways, it may feel like all you can do is throw your hands up and ask, “Why me?!” The good news is that there’s a fix for almost every type of lawn nuisance, but first, you’ve got to pinpoint the cause. How can you tell if the issue is disease or pest-related? We asked a couple of experts how to spot the differences. 

Types of Lawn Pests 

Lawn pests typically fall into two categories: bugs and rodents. Some of the most common insect culprits are white grubs, chinch bugs, sod webworms, armyworms, and mole crickets. 

“Grubs chew roots, leaving brown patches that pull up like a rug, while chinch bugs dry out sunny spots and make grass look like it needs water (but more  watering doesn’t help resolve),” says Teri Valenzuela, natural science manager at Sunday Lawn Care. “Webworms and armyworms chew grass blades and leave small brown patches or droppings. You might also see tunnels or soil mounds from pests like mole crickets.” 

As for rodents, the most common nuisances are voles and moles, though field mice and groundhogs can disturb lawns and gardens in some areas, as well. Voles create shallow surface tunnels and chew on grass and plant roots, often leaving behind narrow, snake-like trails in your lawn. Moles, on the other hand, dig deeper tunnels and push up soil into noticeable mounds, which can disrupt grass and garden beds. 

Field mice create small burrows or use existing tunnels from other animals, and their damage usually involves nibbling on roots, seeds, and bulbs. Groundhogs (or woodchucks) are larger rodents that dig extensive burrows with large entry holes and leave behind tell-tale dirt piles. 

Signs of Lawn Pests

To sum it up, these are the most common signs of lawn pests from either insects or rodents: 

• Brown patches that pull up like a rug
• Dried out spots that don’t get better with water 
• Chewed or ragged grass blades
• Thinning grass or bare spots
• Uneven ground or soft, spongy areas from underground tunnels 
• Visible disruption of soil/grass with shallow tunnels 
• Plants or vegetables disappearing or having gnaw marks 
• Feces 
• Soil mounds 

How to Treat Lawn Pests 

Start by identifying the pest, which you can do with a DIY soap flush. “Mix dish soap with water and pour it over a small patch of lawn,” Valenzuela says. “If bugs come to the surface, it helps you know what you’re dealing with.”

For most pests, good lawn care goes a long way: Mow high, water deeply, and don’t overfeed. If damage is spreading or intense, Valenzuela says that a broad-spectrum, lawn-safe insecticide may be needed.  

As for rodents, you can try a repellent or poison, advises Lou Manfredini, home and garden expert for Ace Hardware. “Poisons like Sweeny’s poison peanuts can be quite effective,” Manfredini says. “And Bonide Sonic Spike is a battery-operated repellent that sticks in the ground and can have good results repelling the rodents without killing them.”

Types of of Lawn Diseases 

Lawn diseases are typically caused by fungi, not insects or rodents. Common ones like brown patch, dollar spot, and red thread leave discolored or thinning patches. “Unlike pests, which chew or dig, fungi infect grass blades directly,” Valenzuela says. “You won’t see the fungus, but you’ll see the spots, fuzz, or odd discoloration it leaves behind.”

Manfredini adds that lawn disease is often caused by poor conditions. For example, if you water too little or too much, have unhealthy soil, or mow with dull blades, you could be setting the stage for lawn disease. Compacted soil, poor drainage, and heavy thatch buildup can also create an environment where fungus thrives. 

Signs of Lawn Disease

• Yellow, brown, or gray patches that spread over time
• Thinning or dying grass despite adequate watering
• Grass blades with lesions, streaks, or unusual color changes
• Whitish, pink, or red fuzz or thread-like growth (especially in morning dew)
• Affected areas that don’t pull up easily like grub-damaged spots
• Patches that seem to worsen after rain, high humidity, or overwatering
• General decline in lawn health despite regular care

How to Treat Lawn Diseases 

To keep the lawn as healthy as possible, start by zeroing in on your soil condition. “Compacted soil is an evil empire for lawns,” Manfredini says. “Core aeration and then removing the dead thatch is job one for loosening up the soil and allowing the grass to breathe better.”

He adds that using soil amenders (like Scotts Foundation or Milorganite) can then help loosen the coil along with peat moss and topsoil. Also, identify and correct low spots in your yard so water doesn’t accumulate, and avoid overwatering these areas, as well.  

Before applying any treatments or fungicides, you must first identify the exact issue, Valenzuela adds. Misdiagnosing can lead to wasted time and money. When in doubt, take a lawn sample to your local extension office for help.

Some more ways to keep your lawn healthy and thriving include mowing with sharp blades and not cutting more than ⅓ of the grass height, watering deeply but infrequently (ideally in early morning), and keeping a tidy yard free of lawn clippings and debris. You can also rotate your mowing direction each time to reduce stress on the grass.