Velvetleaf (Abutilon theophrasti)
WEED ALERT
FAMILY: Mallow
OTHER NAMES:
Elephant-Ear, Indian mallow
DESCRIPTION:
Annual reproducing by seed
STEMS:
- 3 to 6 1/2 feet tall: occasionally taller much branched towards upper
portion of plant
- soft, hairy, velvety
LEAVES:
- large, heart-shaped (3 to 8 inches wide)
- soft, hairy and very velvety to the touch
FLOWERS:
- yellow to yellowish-orange
- 5 petals
- 1/2 to 1 inch wide when open
- flowers from late July to August
FRUIT:
- circular cluster of 12 to 15 seedpods 1/2 to 1 inch long
SEEDS:
ROOT:
- slender taproot with many smaller branches
CONCERN:
Velvetleaf was discovered in B.C. at Chilliwack in 1990 as a small infestation in corn and raspberry plantings. Rated as one of the worst weeds in the U.S. velvetleaf now infests extensive corn and soybean acreages in Ontario and Quebec.
Costs for control in the U.S. in one year alone were estimated at $343 million.
Prevention to reduce the chances of introduction into a clean field should receive high priority.
Velvetleaf causes crop losses by:
- severe crop competition - up to 70% reduction in corn yield
- hosting insects, disease organisms and nematodes
- producing chemicals which may reduce crop seed germination and root formation
Why is velvetleaf such a
successful weed?
- produces 700 to 17,000 highly viable seeds per plant
- seeds can remain viable in soil for over 50 years
- seeds germinate throughout the year
- high seedling vigour
- can still produce seed under competition
What Can You Do?
- Survey fields early! Look for small seedlings with velvety heart-shaped leaves and toothed edges.
- Apply pre-emergence herbicides followed by cultivation and post-emergence herbicides (prior to 2 to 4 inches in height). Contact the B.C. Ministry of Agriculture and Food for appropriate herbicide recommendations.
- DON'T rely on "one-shot" weed control! It won't work! Velvetleaf germinates over an extended period.
- Report sitings or suspicious plants to your District Agriculturist.
Velvetleaf Seedlings
Photographs courtesy of Dean Swan, Washington State University (retired)
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