Stop Noxious Weeds, by Land and by Seeds!
Noxious weeds are sneaky. Each one has its trick for taking over: many spread by seed, while others use stem and root fragments, underground rhizomes, or aboveground runners. Anytime you’re out around a noxious weed, make sure you know how it reproduces, and don’t let it use you to invade!
One of the main methods of weed dispersal is via seeds and other propagules that latch onto boots, pant legs, pet fur, tires, and other moving objects. Some, like the infamous garlic mustard (Alliaria petiolata), are really hard to see once they’re mixed in with mud and dirt. When you’re working around these plants, always use a boot brush to clean seeds and soil off of you, your pet, and your friends before leaving the site.
Garlic mustard (Alliaria petiolata), a Class A noxious weed, has black seeds that are almost invisible in soil. Photo by Weed Specialist Maria Winkler. Brush your boots to keep weed seeds on-site! Kiwanis Ravine workers use this log to brush their boots after walking through garlic mustard. As these garlic mustard rosettes show, it really works! For extra fun and friendly boot-brushing, try this buddy system brought to you by Erin Haley and the rest of the King County Noxious Weed Control Program’s Riparian Team! Featuring Riparian Specialists Justin Brooks and Sayward Glise.
When it comes to many weeds that spread by stem and root fragments (and those going to seed), don’t toss them in your backyard compost pile. They can re-root and grow right out of it. Instead, put them in your city-provided yard waste bin or in the trash, depending on the species. For disposal tips and other information on a specific noxious weed, visit our website.
Yellow archangel (Lamiastrum galeobdolon) spreads via stem fragments, forming dense patches in forest understories and other shady areas. Do not throw this plant in your backyard compost pile; instead, place it in a city-provided yard waste bin. Photo by Sasha Shaw.
Many of King County’s noxious weeds are going to seed right now, so it’s crunch time to control them. Good luck out there—drink water, wear sunscreen, and don’t forget to brush your boots!
Weeds can be never-ending headache
In the weather forecast last week, the meteorologist stated that we have had 33 straight days of above average temperatures. I believe it – May was hot! We also had quite a bit of rain, so between the water and heat, the weeds have gone berserk. I swear I pull one out and two more show up in its place. It is like a B-grade horror movie.
What is a weed? I like this definition from www.dictionary.com: “A weed is any undesirable or troublesome plant, especially one that grows profusely where it is not wanted.” I want grass in my lawn but not poking out between the bricks in my sidewalk and patio. My woolly thyme and pink chintz thyme are growing in the bricks, but I think they look attractive. What I am saying is, what constitutes a weed is sometimes dependent on where it is growing, kind of like that statement, “Beauty is in the eye of the beholder.”
While weeds are definitely annoying and eliminating them feels like a never ending battle, they are not merely a cosmetic issue. Weeds interfere with the plants we do want growing in our farm fields, lawns, flower beds and vegetable gardens. Weeds steal water and nutrients. Weeds can shade the desirable plants so that they do not get sufficient sunlight. Some weeds even emit a toxin which harms neighboring plants.
Weeds can do all these evil things and drive us insane due to several common attributes. They are very hardy and can survive in a wide range of conditions. Some have waxy leaves that prevent water loss so they are more tolerant of drought and heat; purslane is a good example. Some like Canada thistle have very deep rooting systems, allowing them to access water that more shallow rooted plants cannot reach. Weeds produce lots of seeds, sometimes thousands. One bedstraw plant can bear 100 to 3,000 or more seeds. Many weed seeds can survive years in the soil. The nasty and invasive wild garlic mustard seeds can remain viable for seven years or more! And lastly, weeds have creative ways of dispersing. When disturbed, the seeds of the hairy bittercress can shoot out 16 feet from the mature plant. Dandelion seeds drift through the air, and the cockleburs and burdock seeds stick to clothing and pets. Many weeds have seeds that float on water and wash up in a new location.
Take heart. Diligence and dedication are key to surviving the war on weeds.
• Pull early and often. Pull weeds with the roots intact. Many weeds can reproduce via rhizomes or stolons, what many refer to as runners, so getting all of that plant material out is critical. Ground ivy, yellow nutsedge, and johnsongrass fall into this category.
• Wear protective clothing. Plants such as poison ivy, wild parsnip, and stinging nettles, just to name a few, can cause skin irritation, blisters or worse.
• Mulch is very helpful as it shades the weed seeds and can reduce the number that germinate. Mulch also keeps the soil moist when it gets hot and dry, which makes it easier to pull weeds.
• Landscape fabric and plastic can be used as well.
• Herbicides can be another option or a supplement to weed pulling. Know your weeds, so you know the appropriate product to use and when to use it. Read and follow all label directions!
• Timing is important. Never let the weeds go to seed. As Benjamin Franklin said, “an ounce of prevention is worth a pound of cure.”