Identifying Tall Fescue in Your Lawn and Dealing with Dog Urine Damage

Is It Tall Fescue?

A homeowner in Southern Ontario sees clumps of wide-bladed grass in a fine-bladed Kentucky bluegrass lawn. This is almost certainly tall fescue (Festuca arundinacea)—often confused with crabgrass. Key differences:

• Tall fescue: Perennial, coarse blades, deep roots, forms clumps, stays green in drought.
• Crabgrass: Annual, lighter green, spreads by stolons, dies at first frost.

Why Was It Planted?

Tall fescue is intentionally added to seed mixes for its wear tolerance (kids, dogs, parties), drought resistance, and weed suppression. It's not "cheap grass"—it's a premium trait. Some homeowners plant 100% tall fescue lawns.

Removal Options

1. Dig it out: Cut 2–3 inches deep around clumps, remove roots, patch with matching sod/seed.
2. Glyphosate spot treatment: Shield surrounding grass; reseed after 7 days.
3. Manage it: Mow at 3.5–4 inches (tall fescue prefers higher cut). It may blend in acceptably.

Dog Urine Damage: The Real Solution

Dog urine is high in nitrogen and salts—it burns grass like fertilizer spill. No grass is immune, but some tolerate it better:

• Best: Tall fescue (especially 'Kentucky 31'), perennial ryegrass, zoysia.
• Worst: Kentucky bluegrass, fine fescues.

Practical Mitigation

1. Dilute immediately: Pour 1–2 gallons water on spot within 8 hours.
2. Train dog to one area: Use mulch or gravel "potty zone."
3. Dietary supplements: Some claim to reduce urine nitrogen; evidence is mixed.
4. Reseed damaged spots with urine-tolerant variety.

Sugar Myth

One homeowner suggested sugar on urine spots. Sugar feeds microbes but doesn't neutralize nitrogen/salts. Water dilution is the only immediate fix.

Bottom Line

Tall fescue clumps are a feature, not a flaw—unless you demand a uniform bluegrass carpet. Dog urine damage is manageable with prompt watering and smart grass selection. Accept some imperfection; a living lawn will never be flawless.