Why Is My Lawn Yellow? What Can You Do?

If you've been looking out your window and wondering why your once-green lawn is now tinged with yellow or brown, you're not alone. Many Ottawa homeowners are noticing the same thing this summer — and it's not due to neglect. In fact, this year’s lawn stress is largely the result of an unusual combination of weather patterns, insect activity, and common maintenance missteps. Below, we’ll break down the primary reasons your lawn might be turning yellow — and what you can do about it.

1. Drought Stress: A Dry Year with Hot Consequences

This summer has been significantly drier than normal. Lawns typically need about 25.4mm (1 inch) of water per week, or roughly 101.6mm per month, to stay healthy. Between April and July, that adds up to 406.4mm — the amount of water needed to sustain root health, growth, and colour.

Here’s how 2025 has shaped up compared to last year:

In 2025, we’ve only received 271mm — that’s 33% less than the necessary amount.

Now combine that with 11 days over 30°C in July 2025, compared to only 2 such days in July 2024, and we’ve got the perfect recipe for drought stress.

What does drought stress look like?

• Grass turns yellow, tan, or crispy brown
• Growth slows or stops altogether
• The lawn may feel crunchy underfoot
• Recovery is delayed without adequate water

What can you do?

• Water deeply, infrequently — ideally 1" per week in the early morning (increase during heat/drought periods)
• Let dormant grass rest — avoid traffic and mowing
• Apply Liquid Aeration and Overseed in the fall to help recovery

2. Chinch Bug Damage: Tiny Pests, Big Impact

Another major culprit behind yellow or browning turf this year? Chinch bugs. These tiny insects thrive in hot, dry weather — exactly the conditions we've had this summer. They feed on turfgrass by piercing the blades and sucking out moisture, releasing enzymes that block water movement within the plant. The result? Grass that looks yellow or brown and appears to be dying from drought, but is actually being attacked from within.

Kentucky bluegrass is especially vulnerable to chinch bugs, and their populations can spread quickly in stressed lawns.

Signs of chinch bug damage:

• Irregular patches of yellow or brown grass, often in sunny areas
• Damage starts near sidewalks, driveways, or garden edges
• Bugs may be visible at the base of the grass on close inspection

What can you do?

• Apply BioTitan, a targeted solution that helps reduce chinch bug populations
• Re-establish damaged areas with fall seeding services
• Maintain adequate lawn health to build natural resistance

3. Mowing Mistakes: Timing and Technique Matter

You might think mowing is a harmless chore, but during extreme heat and drought, it can actually do more harm than good. When grass is already under stress, mowing can cause further injury, especially if it's done improperly.

What happens when you mow in hot, dry weather?

• Scalping & Crown Exposure: Dry, brittle grass is more prone to scalping, which exposes the crown — the plant’s growth point — making it vulnerable to death.
• Moisture Loss: Mowing increases evapotranspiration, speeding up water loss and deepening drought stress.
• Injury to Dormant Grass: Many cool-season grasses (like bluegrass) go dormant to survive heat. Mowing during dormancy disrupts this protective mechanism.
• Dull Blade Damage: Dull mower blades tear grass instead of cutting it cleanly, leaving frayed tips that brown quickly.
• Weed & Disease Risk: A stressed or injured lawn is more susceptible to weed invasion and fungal infections.

Best mowing practices in drought conditions:

Avoid mowing if your lawn is dormant or brown. If mowing is necessary:

• Raise your mower blade to 2.5"– 3"
• Always use sharp blades
• Mow during early morning or late evening
• Leave clippings on the lawn to shade the soil and retain moisture

Final Thoughts: Yellow Isn’t Always the End

While a yellow lawn can be worrying, it’s often a temporary state brought on by environmental factors beyond your control. Grass is remarkably resilient — especially if you give it time, proper care, and the right fall recovery plan.

What can you do next?

• Avoid unnecessary stress on the lawn
• Hold off on overwatering or mowing during peak heat
• Make a plan for fall liquid aeration and overseeding
• Consider professional solutions like BioTitan for insect control

Your lawn may not be a lush green oasis right now, but with the right steps, it can bounce back beautifully by fall.

For these, and more tips, visit us at https://www.nutrilawn.com/ottawa.

If you are unsure about what is happening on your lawn, feel free to call us at 613-739-3399 or email ottawa@nutrilawn.com. Our experts will be happy to help you.

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