White Sweet Clover

Melilotus albus

Description 4

Sweetclover is an annual or biennial plant in the pea family that can grow 2 m tall but is usually less than 1 m. It rapidly colonizes gravelly well-drained soils such as roadsides, waste areas and river banks and bars. A single plant can produce 300,000 seeds and the seeds remain viable in the soil or under water for many years (80% survival after 30 years). This is likely Yukon’s most invasive and problematic species. It is planted in agricultural areas to increase soil nitrogen.

Range in Yukon 4

White Sweetclover is widespread throughout southern Yukon. It is known along much of the Alaska, North Klondike, Robert Campbell, and Top-of-the-World highways and 30 km up the Dempster Highway. It has proven to be highly invasive along the La Biche River in southeast Yukon. The only sites known on the Yukon River in Yukon are Whitehorse, Carmacks and Dawson; although it is a serious problem on Alaskan waterways including tributaries of the Yukon River.

Similar Species 4

Yellow Sweetclover (Melilotus officinalis), the yellow coloured relative, is widespread throughout southern Yukon, though not as abundant as its cousin

Ecological Impact 4

White Sweetclover readily invades open areas and forest clearings as well as on river banks. It can form large monospecific stands, overgrow and shade native species. It will degrade natural grasslands.

Control 4

Plants should be pulled or cut before or during flowering. First-year plants may re-grow and can be cut again. Pulling or cutting will have to be repeated over a number of years to deplete the seed bank. If mature seed is not present, plants can be left where they are pulled. The plants quickly die once removed from the soil.

For more information visit: Yukon Invasive Species Council

Sources and Credits

  1. (c) Steve Chilton, some rights reserved (CC BY-NC-ND), http://www.flickr.com/photos/73779416@N00/812318237
  2. (c) Andrey Zharkikh, some rights reserved (CC BY), https://www.flickr.com/photos/zharkikh/6659902267/
  3. (c) José María Escolano, some rights reserved (CC BY-NC-SA), https://www.flickr.com/photos/valdelobos/4798267201/
  4. (c) L.G. Johanson, some rights reserved (CC BY-SA)

More Info

iNaturalist.ca Map

Plant Pea Family (Fabaceae)
Color white