London Free Press March 11, 2014
Go ahead: plant a milkweed, save a monarch.
The milkweed plant soon will be yanked from the province’s “noxious weed” list that would ordinarily require it be destroyed on crop-land.
Taking its place on the bad-plant list will be the quirkily named dog-strangling vine.
That’s a double score for butterfly lovers, who say the mandatory destruction of milkweed and the invasion of dog-strangling vine have contributed to an alarming population drop the queen of the butterflies.
Milkweed “is very, very important to monarchs. Their caterpillars eat only milkweed,” says Ann White of London, who is the butterfly count co-ordinator for Nature London.
But the plant has been vanishing from farm fields, field fringes and pastures, assisted by a provincial weed law that encourages herbicide treatment to prevent its spread.
White and other vocal lepidopterists have been lobbying the Ontario Agriculture Ministry for the changes.
Ministry spokesperson Mark Cripps said the proposed move is also an effort to improve the Ontario’s biodiversity.
Farmers so far haven’t objected, although the province is still receiving public comments to its environmental registry until April 14.
The invasive dog-strangling vine – a perennial that can grow as high as two metres but, despite its name, poses no threat to dogs – crowds out other plant life and is a menace in its own right.
Monarchs often lay eggs on its leaves but their larvae can’t survive on the plant, Cripps said. “It interrupts the monarch life cycle,” Cripps said.
Monarchs breed in Canada and the U.S. but migrate to a small forest in a mountainous area of Mexico, where they over-winter. There, their habitat is also being destroyed and the over-wintering population last year was calculated as the smallest in 20 years.
Defined as plants harmful to living things (crops, livestock) and injurious to health.
- 23 plants in Ontario on the list. Milkweed has been included because it can reduce crop yield and can be poisonous to livestock. Usually controlled by herbicides.
- On current list are: common barberry, European buckthorn, bull thistle, Canada thistle, wild carrot, Colt’s foot dodder, goat’s beard, Johnson grass, knapweed, milkweed, nodding thistle, poison hemlock, poison ivy, proso millet, ragweed, yellow rocket, Russian thistle, Scotch thistle, sow thistle, cypress spurge, leafy spurge, tuberous vetchling, giant hogweed.
- Everyone who owns crop land must destroy noxious weeds on it.
- Everyone who has land near enough to farmland that noxious weeds could affect crops must also rid the property of those weeds.