Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. Growing Requirements for Golden Loosestrife Plants Golden Loosestrife are easy to grow, undemanding plants that are hardy in USDA zones 5-10. Apart from the heavy garden loosestrife infestation and reed canarygrass (Phalaris arundinacea), the slough has remarkably few invasive plants. Yellow archangel can be managed using specific herbicides. Garden loosestrife was introduced to North America from Europe as an ornamental in the 1900’s and is now naturalized in wetlands and lakeshores in parts of the northwest, midwest and eastern United States and Canada. It looks very pretty when the purple leaves first come out in the spring. You can find their recent results in this presentation. Yellow loosestrife’s flowers are more pointed than those of garden loosestrife. Whatever the reason, King County’s garden loosestrife is a beast of a plant, and it’s really hard to get rid of. However, the noxious garden loosestrife has branched flowering stems with flowers clustered near the top of the plant (not just in the leaf axils), less than ½ inch wide, with distinct orange margins along the edges of the sepals, and it is more likely to be found in wetlands than gardens. The following provides both cultural and chemical control options for common weeds found in Minnesota lawns and landscapes. As with garden weeds, control of these plants includes mechanical removal such as digging the plants out by hand, and use of a systemic weedkiller. Garden loosestrife infestation at Marymoor Park on Lake Sammamish. Soak the soil down several inches. Shouldn't your neighbors have some say in whether to have this sprouting all over their yards? We map all known locations of regulated noxious weeds such as garden loosestrife in order to help us and others locate new infestations in time to control them. Remove faded flower stems for a neat appearance. Garden loosestrife has two major look-alikes: purple loosestrife (Lythrum salicaria) and yellow loosestrife (Lysimachia punctata). Weed Specialists Sayward Glise and Ben Peterson surveying Rutherford Slough. Glyphosate herbicides are very effective for killing loosestrife. I have Gooseneck Loosestrife that has really taken over in my flower garden. It is important to dispose of the plants away from the water. Yellow Loosestrife Lysimachia punctata. “It’s popping,” says Weed Specialist Sawyard Glise, who joined Ben Peterson for a survey of the slough earlier this month. The pondweed can quickly destroy other plants in the pond due to its fast-growing rate. The edges of the petals don’t have the same fringe of hairs as seen in L. punctata, and sepals are hairy with a conspicuous orange margin The flower spreads through rhizomes to form colonies and does not usually produce seeds. The bushy plant can grow up to six feet on top of the water. We’ve since made a big dent in the southeast part of the slough, which we’ve treated almost every year for the past eight years, as the below before and after photos show: Rutherford Slough in 2003. Mowing can help to slow a population’s growth, especially its spread by seed, but won’t eradicate it. Dig it up as best you can and then treat the area with boiling water. This product comes with a hand held sharpener, a 25 foot polypropylene rope and folds up for easy storage. Vigorous plants can be divided in the spring or fall. Pulling purple loosestrife by hand is easiest when plants are young (up to two years) or in sand. Most gardeners are aware of the problems caused by weeds, but there are garden plants - readily available to buy - that have the potential to become a nuisance. Garden loosestrife spreads primarily through its red rhizomes, which can extend up to 10 ft. Garden loosestrife also produces seeds in egg-shaped capsules, each of which holds a few seeds. Governments are aggressively trying to get rid of yellow loosestrife in various regions. How To Get Rid Of Purple Loosestrife. After this, keep a sharp eye out for any stray sprouts and pull these as soon as you spot them. There are also populations of garden loosestrife in the Snoqualmie Valley including one large infestation around the edges of a oxbow slough near Fall City, scattered along the shores of the Snoqualmie River and its tributary the Raging River, on Lake Alice, and in a few other isolated wetlands and roadside locations. Aggressive plants can take over even the most meticulous garden. Watch for slugs and snails. These days, garden loosestrife infests the shorelines of Lake Washington, Lake Sammamish, and the Sammamish River, with smaller populations on Lake Burien, Rutherford Slough, the lower Snoqualmie River, the Raging River, and a few other locations. The branched stem bears tapering leaves in pairs or whorls and terminal clusters of deep-yellow flowers. We first controlled the site in 2002, when garden loosestrife formed an 11 acre monoculture in the slough. At around 4 ft. tall, it’s also shorter than garden loosestrife. Property owners in King County are required to control this plant. Our program’s Aquatic Weed Specialist, Ben Peterson, is currently collaborating with Washington State University’s Tim Miller on a study about the effectiveness of various herbicides and herbicide combinations on garden loosestrife. Watch for rust and leaf spots. Yellow loosestrife’s flowers grow all along the stem. Smoke exuded by the burning yellow loosestrife is used by people to keep off snakes. No spraying necessary, it took me no more than 4 minutes to gather them. Now one might think that a loosestrife with the species name terrestris was more terrestrial than most, but it seems to be like most loosestrifes – they like boggy ground around water. Post was not sent - check your email addresses! It usually grows 3-6 feet tall—sometimes reaching 10 feet—with round, erect stems covered in soft hairs. Often loosestrife is taller than the surrounding vegetation, so you can spray the top of the plant. The weed ended up being much more widespread, and harder to kill, than we’d expected. Education Specialist Sasha Shaw holds a garden loosestrife plant on the Raging River. But this weed hangs on. For more information, see Noxious weed lists and laws. Good question! Yellow loosestrife (Lysimachia punctata) is a more closely related species that can be harder to tell apart from garden loosestrife. Home › Program News › Garden Loosestrife – August 2017 Weed of the Month. When using herbicides, always read and follow label directions for rates, spraying conditions, personal … The trouble with trying to get rid of Canada Thistle lies in the extensive root structures the invasive weeds extend into the soil. Garden loosestrife’s flowers appear in clusters at stem ends. Run a sprinkler or drip system for 20 minutes to a half hour every 5 to 7 days when rainfall is sparse. If you see a regulated noxious weed in King County, there are three ways to report it: You can call us at 206-477-WEED (206-477-9333), email us at, or fill out our online “report a weed” form. Education Specialist Sasha Shaw holds a garden loosestrife plant on the Raging River. Glyphosate is available under the trade name Roundup. To contact staff, see the Noxious Weed Control Program Directory, send an email, or call 206-477-WEED (206-477-9333). Leaves and stems are finely downy. Gardeners may buy these 'thug' plants unaware that, once established and given the right growing conditions, they can run amok. Apply Herbicide: Wet about 1/4 to 1/2 of the leaf areas of each plant (a "clump" of loosestrife is an individual plant), taking care to avoid spraying other species. Sorry, your blog cannot share posts by email. Categories: Program News, Weed Control, Weed Identification, Weed of the Month, Tags: garden loosestrife, King County, loosestrife, Lysimachia punctata, Lysimachia vulgaris, noxious weeds, rivers, Rutherford Slough, Snoqualmie River, Weed Control, wetlands. Even if … Purple loosestrife can be cut or pulled without a permit in Minnesota. You can also find information on herbicide treatment, as well as ID and control methods, at the following pages: Garden Loosestrife Best Management Practices. The plant has square stems with lance- to oblong-shaped, smooth-edged leaves. But we continue to battle the infestation, especially in the northwest half of the slough, where control has been intermittent for external reasons. Krishona Martinson, Robert Mugaas and Karen Vydimar. ... (get rid of) strife’ implication in its common name. Control methods: 1) Physical removal is an option for seed and root reduction. The invasions are especially worrisome because the plants can clog shallow waterways and displace native vegetation, reducing habitat for waterfowl and fish—including several important salmon species. First, although it shares habitat and invasive tendencies with purple loosestrife (Lythrum salicaria), it looks very different and is not even related to this other noxious wetland invader. As the name implies, its flowers are purple or magenta, appearing clustered in tall, dense spikes. For flowering mature plants, you can also cut the plants at the base to prevent seeding. Purple Leaved Loosestrife is perhaps the worst offender, of the two. Enter your email address to follow this blog and receive notifications of new posts by email. Prescribed Burning Burning is thought to not be an effective control method because purple loosestrife is typically found in a wet soil condition and the rootstock of the plant is well-protected. In the distant past these and several other kinds of ‘loosestrife’ plants were also used to get rid … They can reroot if you leave them behind. Identifying garden loosestrife (also known as yellow loosestrife) can be confusing, especially by its name. The key is to be vigilant and patient. Both have bright yellow 5-petaled primrose-like flowers on tall, softly hairy stems. Purple loosestrife spreads through seed, producing up to 2.5 million seeds per plant, as well as via roots and vegetative growth. Many plants require only … Garden loosestrife (Lysimachia vulgaris), a Class B noxious weed from Eurasia, has managed this impressive takedown. The first, purple loosestrife, is easier to identify. Yellow Loosestrife is generally not subject to serious pest or disease issues. Rutherford Slough’s garden loosestrife infestation has been partially controlled, but we’re still trying to find the best way to eradicate the plant. Rutherford Slough, near the Snoqualmie River in Fall City, has been a particular focus area for our program. 1 Response. Leaves and stems are softly hairy. Please notify us if you see garden loosestrife growing in King County. The Eurasian yellow loosestrife (Lysimachia vulgaris), an erect plant 0.6 to 1.2 metres (2 to 4 feet) high, is common on riverbanks in England and grows in eastern North America. In 2007, our program received a grant from the Washington Department of Ecology to control garden loosestrife along the Snoqualmie River, thinking the plant had spread into the river from Rutherford Slough. Garden loosestrife was introduced to North America from Europe as an ornamental in the 1900’s and is now naturalized in wetlands and lakeshores in parts of the northwest, midwest and eastern United States and Canada. Garden loosestrife’s flowers appear in clusters at stem ends. Garden loosestrife is a Class B noxious weed in Washington. (In its native range, garden loosestrife tops out at about 4-5 feet) Its 3-5 inch long, ovate leaves occur in whorls of 3 (sometimes 2 or 4) and have hairy undersides. What plant is so tough that it can outcompete common cattail (Typha latifolia), purple loosestrife (Lythrum salicaria), and even Himalayan blackberry (Rubus armeniacus) along King County’s shores? A layer of mulch will help keep soil moist (see below). And it spreads. The Eurasian yellow loosestrife (Lysimachia vulgaris), is an erect plant about 2 to 4 feet high. Garlic mustard and purple loosestrife are both well publicized no-nos, but always good to see recurring advisement to rid them from your patch of planet. While not commonly referred to as a loosestrife, another Lysimachia that is an invasive plant is Lysimachia nummularia. And spreads. Purple loosestrife’s lance- to oblong-shaped, smooth-edged leaves. Yellow loosestrife (Lysimachia vulgaris) is a lovely tall British native perennial with whorls of broad lanceolate mid-green almost stalkless leaves and clusters of bright yellow cup-shaped flowers with pointed petals 1.5 – 2cm across throughout July and August. new loosestrife seedling development. Like most loosestrifes that I am familiar with, it has yellow flowers, so the common name Yellow Loosestrife is a bit useless. Showy, yellow, 5-petaled primrose-like flowers appear in clusters at stem ends between July and September. Searching for "Loosestrife eradication" on Google, I see that this is not uncommon. We look forward to hearing from you! While taking Yellow Loosestrife care, its diseases should be taken into consideration as it affects the health of the plant. Garden loosestrife displaces native vegetation along streambanks, wetlands and shorelines and reduces habitat needed by waterfowl and fish, including several important salmon species. As always, if you have any questions about garden loosestrife identification or control, feel free to call us at 206-477-WEED (206-477-9333) or email us at Flower bases are ringed by green sepals with distinct orange-brown edges. Control options for common Minnesota lawn and landscape weeds. Garden loosestrife is a perennial plant that grows in wet areas such as river and stream banks, lakeshores, and wetlands.