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If you have noticed a sea of chartreuse in the roadside ditches, it's not flowers but rather leafy spurge. It is characterized by flower parts in threes with a milky latex sap, Maybe it's the reason it's also called wolf's milk.

Leafy Spurge is an invasive herbaceous perennial that spreads rapidly from seeds and rhizomes. Native to Eurasia, this troublesome weed has become widespread in the U.S. and is a particular problem in open rangeland in the Upper Midwest and Northern Great Plains states. It is present throughout most of Minnesota.

The yellow-green bracts open in May and June, and the flowers appear from June to August. The alternate linear leaves are about 1/2-inch wide with wavy margins. Leafy spurge may be mistaken for whorled milkweed, which also has linear, bluish-green leaves with milky sap. The smooth, 2 to 3 foot tall stems rise from a woody perennial crown.

The plants compete by utilizing moisture and nutrients, and shading other plants. Rhizomes may spread several feet a year. The many buds on the rhizomes make leafy spurge very difficult to eradicate. Vertical roots extend as much as 15 feet deep. In addition, plant toxins may prevent growth of other plants around them. Leafy spurge also spreads by seeds, which are explosively dispersed from the capsules and can be thrown up to 15 feet. The seeds are also spread by roadside mowing and haying. It prefers light, dry soils and full sun, conditions found at many roadside and construction sites.

Leafy spurge is found throughout the world, except in Australia.

It was first recorded in the U.S. in 1827 in Massachusetts, where it probably had been transported in a bag of seed. It reached North Dakota within 80 years of its arrival in the U.S.

The impact of leafy spurge on rangelands has been significant. The white latex sap is toxic to grazing wildlife and livestock, although goats and sheep eat it without harm. The latex sap can also cause minor skin irritation to humans and even cause blindness upon contact.

Leafy spurge is on Minnesota's list of prohibited noxious weeds, which means that landowners are required to attempt to control or eradicate the plant. If caught early, small infestations can be controlled with herbicides such as picloram or glyphosate. Due to its extensive rhizomatous root system, it is difficult to control through pulling or digging. Burning is sometimes used along with chemicals to control it.

One of the most promising long-term management strategies is the use of bio-control agents. The Minnesota Department of Agriculture reports they have imported several species of European flea beetles. These beetles feed almost exclusively on leafy spurge and a few related species. Flea beetles from established populations are actively collected and relocated to leafy spurge-infested sites.

If you are sure you have leafy spurge on your land, notify local government agencies so appropriate management can begin.

This information was taken from an article written by Nancy Rose, U of M Regional Extension Educator Horticulture. You can view the entire article at: http://www.extension.umn.edu/yardandgarden/YGLNews/YGLNewsJune152007.html#leafyspurge

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PLANT CLINICS: Volunteer Master Gardeners will be available Mondays, from 4:30-7 p.m., at the Extension Office in North Branch ,at 38780 Eighth Avenue to answer your gardening questions. You can also call 651-674-4417 during these hours to speak with a Master Gardener. Samples can be dropped off during the day on Monday if you cannot stop in during clinic hours.

Please note: MONDAY is the only day you can drop off samples, as there is no longer staff at the North Branch Office who can answer gardening questions.

VOICE MAIL: You can leave a question for a volunteer Master Gardener at 651-674-4417. Depending on the volume of calls, they try to respond within a couple of days. During office hours ask for the Master Gardener voicemail, after hours, select ext. 18. You can also get your question answered on the web at: www.extension.umn.edu/askmg.

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