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Wild madder is, like sweet woodruff, in the Galium genus. Wild madder is also called “bedstraw.” Apparently, people did actually once use this weed as a bedding material. Sweet woodruff is a creeping, mat-forming perennial that pretty clusters of white star-shaped flowers in spring and has very fragrant, lance-shaped dark-green leaves.
Ground ivy, a common lawn weed, goes by a number of names. For instance, it is also called “gill,” “gill-over-the-ground” and “creeping charlie.” Although considered a weed, ground ivy has a pretty flower and, when you mow this weed, it gives off a pleasing aroma. Ground ivy is also used as a medicinal herb.
Stinging Nettle (Urtica dioica)
The flowers of stinging nettle plants are inconspicuous. You’ll pay plenty of attention to its barbs, however, if you’re unfortunate enough to brush against stinging nettle! The discomfort these weeds can cause seems incongruous with the fact that stinging nettle is edible. But the young leaves of stinging nettle are, indeed, cooked and eaten by wild foods enthusiasts. Just be sure to pick at the right time and prepare properly to ensure safe consumption.
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Here are 17 types of weeds you might encounter in your garden.
Several of these weeds can cause rashes. Use proper clothing and gloves when working around these weeds, or enlist professional help to eradicate them.
A nonnative perennial herb containing sessile flowers and prominent venation on leaves. It is commonly confused with American plantain (Plantago rugelii) which has petioles that are red-tinged at the base instead of green.
Green foxtail (Setaria italica) grows 2 feet tall with a spikelet seedhead that contains bristles that are lightly tan colored or clear. Yellow foxtail (Setaria glauca) has similar characteristics but grows taller up to a height of 3 feet and its bristles are a tawny yellow color and it has more hairs in the collar region than green foxtail. I’ve found that yellow foxtail is more abundant in southeastern Minnesota.
6. Quackgrass (Elymus repens)
When most people think about weeds they probably think about plants in an abandoned field or on a roadside, but what is a weed? A weed can be defined as a plant that does not belong in a particular place. Different people have different perceptions and ideas of what should and should not be in a place so some weeds we included in this list are certainly not considered a weed by some. So, then why do roadsides have a lot of weeds? In general, roadsides contain a lot of weeds because there is a lot of disturbance. This disturbance creates pockets of available resources and light for weeds. Weeds are weedy because they produce large quantities of seeds and have excellent dispersal characteristics vegetatively and/or by seed. The movement of vehicles, people, and mowers also introduce and move weeds into new areas. Another reason why we may see a lot of weeds on roadsides is because the soil physical and chemical characteristics are often modified creating living conditions that only certain plants can tolerate.
A summer annual native weed that can grow up to 3 feet tall. Leaves are opposite on the bottom of the plant and then alternate above. There is some evidence that common ragweed grows especially well on roadsides and waste places because it can tolerate heavy metal enrichment of zinc, lead, and copper (Bae et al. 2015).
Summer annual grass that grows to a height of 2 feet with several seed stems branching out at the end of the stem. Roots can emerge from the nodes. Smooth crabgrass (hence the name) has a smooth stem with some small hairs in the collar region.
Species like Dog-Strangling Vine (Vincetoxicum rossicum and Vincetoxicum nigrum), Garlic mustard (Alliaria petiolata), Buckthorn (Rhamnus cathartica), and Japanese Knotweed (Reynoutria japonica) threaten biodiversity and have adverse effects on the environment. Species like European Water Chestnut (Trapa natans), Water Soldier (Stratiotes aloides) and Common Reed (Phragmites australis) have adverse effects on recreational activities like swimming, boating and fishing and on reproductive strategies of fish, turtles and birds. Species like Giant Hogweed (Heracleum mantegazzianum), Poison hemlock (Conium maculatum) and Poison ivy (Toxicodendron radicans) can be detrimental to human health with exposure causing allergic reactions and dermatitis.
Do weeds harm the garden?
What weed-killing options can you recommend?
JP: No, all weeds come from the kingdom of plants and all weeds will produce flowers (or equivalent reproductive organs). They're definitely the underappreciated relatives of some of our most beloved garden plants. For example, what may be considered a weed in British Columbia might be considered a garden gem in Ontario. On a larger scale, a beautiful culinary herb that is desirable in Europe and brought to North America for its desirable characteristics can become a menace — even invasive. Such was the case with Garlic Mustard (Alliaria petiolata) which is now a common unwelcome resident in many Ontario gardens.
What makes a weed, a weed?
JP: There are some commonalities which weeds possess in order to gain advantage over desirable ornamental plants. First, they reproduce in a variety of ways. They can spread sexually by seed as well as asexually via rhizomes — a stem that runs underground and shoots out roots like tentacles. Second, some weeds outcompete other species by leafing out earlier and blocking the sun to slower growers. Also, they often hold green leaves later in the fall as well, giving them more time for photosynthesis which ultimately provides them more time and energy to grow, create more seeds and reproduce. By thriving in a multitude of conditions, rapidly establishing and spreading, and by populating areas during droughts, floods and other extreme conditions, weeds have cornered the market on survival.
JP: Weeds can be detrimental in the garden in a number of ways. Some are aggressive and choke out expensive garden plants. Some are allelopathic which means they produce biochemical(s) that influence the germination of seeds and hamper the growth, survival and reproduction of other plant species, which gives them the advantage over more desirable plants. Others, such as Giant Hogweed (Heracleum mantegazzianum), an invasive species which can grow over 12 feet tall, are extremely dangerous in that they cause burns, blisters and even scarring on the skin when touched. And some, such as Water hemlock, Cicuta species are toxic and deadly when ingested.