Weed of the Week: Leafy Spurge
🌿 Weed of the Week: Leafy Spurge (Euphorbia esula)
📸 Quick Visual ID Leaves & Stems:
- Smooth stems growing in clumps, with narrow, waxy leaves that are blue-green and turn reddish orange in late summer.
- Flowers: Small yellow-green flowers in clusters near the stem tips; seed pods can “pop,” dispersing seeds several meters.
- Roots: Deep, extensive root system, up to 9 m deep and 4.5 m wide, that produces new shoots from fragments.
⚠️ Why It’s a Problem
- Designated noxious in Alberta: landowners must control or destroy it under the Weed Control Act.
- Invades rangelands, croplands, and natural areas; its toxic sap deters livestock and displaces native species.
🧠 Identification Tips
- Look for dense clumps 0.2–1 m tall with milky sap if stems are broken.
- Observe leaf colour shifts, from blue-green to reddish hues, later in the season.
- Watch for seed pods drying in late summer/fall; pods can burst and spread seeds.
🛠 Control Methods
Integrated Management is Essential:
- Cultural: Maintain competitive forage cover; avoid overgrazing.
- Mechanical: Regular mowing or tilling can deplete root reserves, mow before seed set and dispose of plant material carefully.
- Chemical: Use registered herbicides during the growing season; always follow label directions.
- Biological: Flea beetles (Aphthona species) can help reduce plant vigour over time.
- Grazing: Goats can safely graze leafy spurge and help reduce density.
✅ What You Can Do Today
- Scout fields in spring and summer for early detection.
- Mow before seed production to prevent spreading.
- Combine methods, cultural, mechanical, biological, and chemical, for long-term control.