Agronomy •  2023-07-05

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Identify & Control: Leafy Spurge (Euphorbia esula) & Common (Yellow) Toadflax (Linaria vulgaris Mill.)

Invasive plant species such as Common Toadflax and Leafy Spurge have cost North America an estimated $26 billion annually since 2010, according to a study conducted in 2021.1 The extensive root systems of Common Toadflax and Leafy Spurge have resulted in them both becoming a significant issue along Canadian roads, railways, and utility lines.

Identifying Leafy Spurge

Arriving in North America in the 1800s as either an ornamental or crop seed contaminant, Leafy Spurge has long been difficult to control. This invasive weed can spread locally through reproduction of its root system, which can reach up to 9 metres deep and 4.5 metres wide, as well as through the transportation of seeds.

Growing in a range of soil types, Leafy Spurge forms dense stands that can produce up to 130,000 seeds. In late summer and early fall, seed pods dry out then explode, shooting seeds up to five metres away from the parent plant.2

Standing up to 1-metre tall, Leafy Spurge stems are smooth, hairless, arranged in clumps, and contain a milky latex. The plant’s many narrow, waxy leaves are blue-green in colour until turning yellowish or reddish-orange in late summer. Its flowers are small, yellowish-green, lack petals and sepals, and form clusters at the tips of stems. Flowering occurs late June through July.

leafy spurge plant    leafy spurge bush

Identifying Common (Yellow) Toadflax

Brought from Europe as an ornamental plant over a century ago, Common Toadflax has become a significant problem along roads, railways, disturbed soils, and waste areas3. Adapted to a wide range of soil types, Common Toadflax prefers sandy-gravelly soils where its extensive, creeping root system can easily flourish, even from seeds two-to-three weeks old. One plant can produce up to 30,000 seeds4, which are small, flat, brown/black in colour and winged to be carried by wind.

Common Toadflax can grow up to 1-metre tall with a slim hairless stem and light green leaves. Unlike Leafy Spurge, Common Toadflax stems do not contain a milky sap. Its snapdragon-shaped flowers have a long spur that point backwards and are about half the length of the flower. Flower colour is mainly butter yellow with orange petal tips, and flowering occurs from June to October.

common toadflax flower     common toadflax plant next to railroad

Powerful solutions for controlling Leafy Spurge & Common Toadflax

Tordon™ 22K herbicide is proven to be the most effective and trusted control option against Common Toadflax and Leafy Spurge. Applied to actively growing weeds, Tordon 22K translocates into the root system to provide extended control of deep-rooted perennials as well as other broadleaf weeds. An easy-to-use liquid formulation packaged in convenient 10L jugs, Tordon 22K can be applied as either a broadcast or spot treatment.

If you are looking for a more economical control option, Aspect™ herbicide is cost-effective for season-long control of Common Toadflax and Leafy Spurge.  Combining two active ingredients formulated into one easy-to-use liquid formulation, Aspect controls deep-rooted perennials like Common Toadflax and Leafy Spurge as well as brush and other broadleaf weeds commonly found on rights-of-way. To increase plant uptake for more effective control, use Gateway™ adjuvant at 0.25 - 0.375% v/v with Aspect. Subsequent treatments may be required in following years.

Application Timing:

Leafy Spurge: Tordon 22K and Aspect herbicide should be applied when leafy spurge is actively growing in the full true flowering stage, prior to seed set. True flowering stage occurs with green flowers are present inside of the yellow bracts.

Common Toadflax: Tordon 22K and Aspect herbicide should be applied when common toadflax is actively growing and the majority of the population is flowering and prior to seed set.

Trust both Tordon 22K and Aspect herbicides to help you get control of these deep-rooted perennial species.

Corteva Agriscience™ has a portfolio of solutions to fit professional vegetation manager's needs. For more information visit or contact your Corteva Agriscience IVM Expert.