Edmonton’s cool, damp springs and humid summer evenings create ideal conditions for several turf diseases. Recognizing symptoms early and applying proper cultural practices can prevent minor outbreaks from devastating your lawn. Here’s what to watch for—and how to keep your turf healthy.
1. Brown Patch (Rhizoctonia solani)
- Symptoms: Circular, straw‑colored patches 6″–3′ across with darker “smoke‑ring” margins.
- Conditions: Warm (20–30 °C), high humidity, overnight leaf wetness.
- Prevention & Control:
- Mow at 2.5–3″ and remove clippings (see guide).
- Water deeply in the morning to allow blades to dry.
- Improve air circulation by pruning nearby shrubs.
- If severe, consider a fungicide labeled for brown patch.
2. Dollar Spot (Clarireedia jacksonii)
- Symptoms: Silver dollar–sized tan spots, often with reddish borders, in low‑nitrogen turf.
- Conditions: 18–27 °C with extended leaf moisture.
- Prevention & Control:
- Maintain balanced fertility (avoid nitrogen extremes).
- Increase mowing height slightly to shade the soil (see guide).
- Apply targeted fungicide only if large areas are affected.
3. Snow Mold (Typhula spp. / Microdochium nivale)
- Symptoms: Light gray or pinkish mats of mycelium under snow cover or after thaw. Grass stems matted together.
- Conditions: Prolonged snow cover on saturated turf.
- Prevention & Control:
- In fall, mow slightly lower than summer height to reduce matting.
- Rake leaves and debris before first snow.
- Ensure good fall fertility (a winterizer).
- Reseed damaged areas in spring.
4. Powdery Mildew (Erysiphe graminis)
- Symptoms: White, powdery patches on leaf blades and stems, often in shaded, poorly ventilated areas.
- Conditions: Cool nights (10–20 °C) and high humidity; shade.
- Prevention & Control:
- Trim tree limbs to increase light and airflow.
- Mow regularly and remove clippings.
- Switch to drought‑tolerant grass blends in persistent shade.
5. Rust (Puccinia spp.)
- Symptoms: Orange‑brown powder on grass blades; blades become thin and pale.
- Conditions: Cool days, warm nights, low nitrogen.
- Prevention & Control:
- Fertilize per schedule (see our fertilization guide).
- Mow at recommended height to remove spores.
- Water early to avoid overnight moisture.
Cultural Practices for Disease Prevention
- Proper Mowing Height: Keep grass at 2.5–3″ to reduce stress.
- Adequate Fertility: Follow a liquid fertilization program suited for Alberta’s seasons (see guide).
- Smart Irrigation: Water deeply in the early morning to minimize leaf wetness (see more watering tips).
- Core Aeration: Improve drainage and airflow—consider our deep‑core aeration service.
- Thatch Management: Dethatch if layer exceeds ½″ to reduce disease harborage.
When to Call in the Experts
If fungal symptoms persist or cover large areas, professional diagnosis and treatment may be needed. Neighbourhood Heroes offers comprehensive turf‑health assessments and targeted disease control as part of our full‑service packages.
👉 Contact us for a lawn health inspection and get ahead of disease this season!