Before we list common landscape weeds in Chicagoland (and Northern Illinois), we should define what a weed actually is. The description might not be what you’d expect:
What is a weed?
A weed is defined as any plant that is growing where it is not wanted. The plant is usually vigorous in nature and may rob resources from desired plants. Robbing resources often allows the unwanted plant to choke-out the desired plant.
According to the Weed Science Society of America, “Many invasive weeds are non-native plants first introduced in North America as ornamentals. Examples include tamarisk (Tamarix sp.), Japanese barberry (Berberis thunbergii) and Scotch broom (Cytisus scoparius).”
However, a weed doesn’t have to be non-native. Any plant can be considered a weed if they create health problems for humans or animals. In some areas of the country, one plant might be listed as a weed since the conditions are right for it to grow all over. But, in other locations, that same plant might be regularly purchased and planted by homeowners without becoming a garden bully.
Landscape weed #1: Bindweed
Sometimes known as wild morning glory, this weed is a beast to contend with. Flowers are usually white or pink and are trumpet-like, and you can spot its thin vines growing around objects or other plants. Once its leaves mature, they’ll be arrowhead or shield shaped.
These vines can grow quickly, often forming its initial runners within one day. After a week or more, they can form large tangled mats that grow along the ground. Bindweed is so quick and dense growing that they’ll choke out other plants (and even trees if left to it).
The true morning glory plant is an annual that will self-seed, rather than re-grow from a root. But bindweed is a perennial and spreads underground through rhizomes. So, trying to hand-pull these is pretty futile, since they’ve already got more babies waiting to sprout underground. Also, hoeing the soil where you find bindweed will only help it spread, and its tiny rhizomes can live for as long as 50 years.
How to Get Rid of Bindweed
Bindweed truly is a haunting garden weed. It’s tenacious and vigorous and will take more than one attempt to get rid of it. The longer bindweed is around, the more it’ll get established and will be harder to eradicate. So, once you notice you have this landscape weed, take action.
If you want to remove bindweed organically, there’s mainly one option: boiling water. But, boiling water is not going to target the bindweed alone. It will destroy any plants you’re looking to keep. Even with this route, it will likely take more than one application to eradicate.
PRO TIP: When applying any chemical during the growing season, it’s important to apply it at the right time of day. The time of day you apply can lessen the impact of the chemical on pollinators. Apply only at times when honeybees have left for the night. Or, apply the treatment early enough in the morning that it can dry by the time pollinators are waking up.
For a chemical solution, use a non-selective weed killer like Bonide’s Weed Beater Ultra (concentrate or ready-to-use spray). Or, try Bonide’s lawn-protective weed killer called Weed Beater Lawn Weed Killer (concentrate or ready-to-use spray). Platt Hill Nursery’s plant pharmacy is well supplied and has everything you need to beat bindweed.
Landscape Weed #2: Black Medic
Black medic weeds can be identified by its teardrop-shaped leaves and is similar in appearance to clover. It’s a low-growing crawling annual that is often confused with clover. But, this yellow-flowering weed is an indicator that your soil has a problem that may need to be addressed. It’s most often found growing next to a sidewalk, driveway, or road but can also be found in lawns.
Black medic is classified as a legume. In fact, it’ll grow black kidney-shaped pods after flowering. Like many legumes, it has a talent for capturing nitrogen from the atmosphere and converting it to usable and plant-available nitrogen in the soil. While this is a beneficial and soil-fixing process, a single plant left untended can form a thick mat that crowds out lawns and other garden plants. A single plant can produce thousands of seeds.
How to Get Rid of Black Medic
Because this plant is an annual that reproduces through seeds, the easiest method of controlling black medic is to pull it out by hand. This is especially effective if you do it before it develops seed pods. It grows a long taproot and can be more easily managed manually with tools, like a fulcrum weeder.
Because black medic needs compacted soil to root properly, you can also get rid of it by using a machine to aerate the soil. To help prevent black medic from returning, add a generous amount of organic matter and till that in during aeration. Platt Hill Nursery’s specialists are able to helps select the best compost for your garden.
In the case of black medic, it’s best to go with a chemical control as a last resort. However, if you’re looking to control black medic and a variety of other weeds in your lawn or garden, try Bonide’s Weed Beater Fe. This is an organic option that is derived from iron and is effective while also greening your lawn. It’s also safe for people and pets when used according to the instructions on the label. Platt Hill Nursery’s plant pharmacy is well supplied and has everything you need to beat black medic.
Once eradicated from garden beds, suppress the opportunity for new plants to germinate by applying a thick (2-3 inch) layer of mulch. Fall is a great time to apply mulch, but it can be helpful for weed suppression at any time during the growing season.
Landscape Weed #3: Common Chickweed
This common weed can be identified by its tiny white flowers atop stems of smooth, egg-shaped leaves growing opposite one another. The leaves are pointed at the tip and the stems are a little hairy or fuzzy-feeling.
Chickweed’s nuisance level is often determined in the eye of the beholder. From a positive perspective, chickweed is actually considered an herb and is said to have a mildly floral, grass-like flavor. Some may value it for its nutritional and herbal medicinal uses, and some may find that it detracts from the beauty of other plantings. Because of its shallow, spreading root system, some may enjoy the weed’s ability to reduce erosion in a landscape.
However, it’s easy to feel haunted by this weed. Any weeded debris like leftover roots or stem parts will regenerate into new plants. It also competes vigorously with other plants, quickly robbing them of nutrients and moisture. And, it’s a known host plant for pests like spider mites and thrips, and diseases that impact tomatoes and cucumbers.
Perhaps the most haunting fact is related to chickweed’s ability to re-seed. Each plant can produce over 800 seeds that have the ability to lay dormant for up to 10 years. They’re also able to produce seeds a mere five weeks after germination.
How to Get Rid of Chickweed
Because of chickweed’s propensity to regenerate from its root and stem parts, hoeing and tilling are not recommended. It’s best to hand-pull these weeds.
Chickweed thrives in lawns that are mowed closely because they need light to germinate. In order to reduce the likelihood of chickweed problems in spring, raise your mower deck in the fall. (An exception to this is the last mow of the season.) This will help provide an early cover during the vigorous spring growth period. Suppress the opportunity for new plants to germinate in garden beds by applying a thick (2-3 inch) layer of mulch. Fall is a great time to apply mulch.
This weed also loves soil that is regularly moist. It often thrives in damp shade gardens and loves cool, wet conditions. So, if you find your lawn overrun with chickweed, try increasing your watering interval period. This would mean more infrequent germination opportunities during the growing season.
But, if these tactics aren’t enough to remove chickweed from your lawn or garden, try Bonide’s Chickweed Clover & Oxalis Killer, available at Platt Hill Nursery.
Landscape Weed #4: Crabgrass
Easily one of the most troublesome and prevalent weeds in lawns and gardens, crabgrass is a rapid-growing course-textured grass. Stems spread out from a center point, but it develops roots at each node or joint in the grass’ stem. Its stem is tinged light purple and can be found in both hairy and smooth varieties. They are warm-season plants that thrive during hot summers when turf grasses typically struggle.
How to Get Rid of Crabgrass
The easiest way to manage crabgrass is to prevent it from re-infesting your yard or garden with seeds. In lawns, this means rigorously maintaining a healthy lawn management plan will be particularly useful. Crabgrass can produce seed with mowing heights as low as ½ inch tall. This is much lower than recommended mowing heights, so be sure not to scalp your lawn in an effort to control this weed. Instead, find a fertilizer that contains chemicals to target crabgrass while feeding your lawn.
Hand-pulling is the best option for garden bed crabgrass management, but Bonide’s Weed Beater Plus Crabgrass is also an option. It’s particularly useful if crabgrass is vigorous around the border of your beds, as it’ll spare turf grasses. Spring prevention can also be helpful, here. Add Preen, corn gluten or Scott’s Halts Crabgrass & Grassy Weed Preventer. Platt Hill Nursery’s experts are ready to help you find the best product for your situation.
Landscape Weed #5: Nightshade
There are many plants in the nightshade family, some of which we cultivate in our gardens like potatoes, tomatoes, and eggplant. But, the varieties that come to mind when mentioning nightshade likely aren’t the delicious kind. Rather, the poisonous and weedy. Three particularly toxic varieties include: black nightshade, bittersweet nightshade, and deadly nightshade. These all have varying levels of toxicity; some in the leaves alone, some in berries, and some in the stems and sap.
According to Illinois Wildflowers, the most commonly found variety in Chicagoland and Northern Illinois is bittersweet nightshade. Its toxicity is particularly potent in both its spear-shaped lobed leaves and the berries themselves. Identify bittersweet nightshade from its purple, 5-petaled flowers with a yellow center. These develop into green, then red, and sometimes deep, dark red berries. The stems are partially woody, which help it grow up and over nearby structures like fences or other plants. If no such structure is nearby, they’re happy to crawl along the ground.
How to Get Rid of Nightshade
Nightshade has a particularly aggressive growth habit and is almost as tough to eradicate as bindweed. This garden nuisance has brittle roots. So, when attempting to pull by (gloved) hand, it’s possible for a small part of the rhizome to be left in the ground. And, this leftover piece would provide the potential to sprout a new plant.
If trying any organic method of removal (such as boiling water), it’s likely to take several applications in order to remove the threat of regrowth from your future. Because this is a particularly toxic plant for humans and pets alike, one may decide to take it out with a swift hit from an herbicide.
The most selective herbicide to try on nightshade includes Triclopyr. Bonide’s Brush Killer, BK32 includes this chemical, which is selective to broadleaf plants and is the least likely to harm nearby plantings or grass. Because Triclopyr is absorbed into stems and roots, however, this may require extra caution when applying near trees or other woody plantings. As always, follow all instructions on the label. If Bonide’s Brush Killer, BK32 doesn’t work to stop nightshade from haunting your landscape, the experts at Platt Hill Nursery are there to help.
If possible, several sources recommend burning nightshade to be sure its berries won’t be snatched by a bird and re-planted elsewhere. This also helps ensure that all toxic portions of the plant are eliminated.
Landscape Weed #6: Nutsedge
Nutsedge is easily identifiable in your landscape or garden bed due to its vigorous growth habit, even when mowed. Plants that have been left to flower and seed are topped with three leaves arranged in a broad star pattern around a cluster of flower stems. The flowers are wheat-y looking and are either yellow or tinted a purple-red. Like all sedge-type grasses, the central stem that supports the flowers has a distinctive triangle shape. It’s distinctive shape is even noticeable in the hand.
If pulling the weed manually, you may also find a dead give-away that you’re working with nutsedge: When analyzing roots that are pulled out with the plant, you may see small tubers, or bulge-looking parts of the root. These are called “nutlets” and are what gives this weed its name.
Nutsedge grows best in areas of the landscape or garden with poor drainage or when over-watered. The leaves of the plant that form at soil-level around the central stem are particularly noticeable after lawn mowing, as they’re much wider than turf grass.
How to Get Rid of Nutsedge
Nutsedge is a perennial weed, meaning it will grow back year after year. But, each time it grows back, it’s likely germinating from the many nutlets it produced the year prior, in addition to the first planting. But, it can also spread through the air when allowed to seed.
Because of all of these factors, it’s best not to pull nutsedge by hand. Pulling by hand would be beneficial to stop the plant from going to seed, but will result in needing to pull several more in a matter of days or weeks.
Instead, try Bonide’s Sedge Ender product. It’s rainproof once dry, so it’s guaranteed to cling to this broadleaf weed without damaging turf grass. And, because it kills down to the root, this chemical will prevent those roots and nutlets from growing.
Landscape Weed #7: Plantain
An initial Google search will likely bring up the benefits of this common landscape weed. It’s true: it does have many benefits. In fact, it was cultivated in Pre-Colombian Europe for its nutty, asparagus-like flavor. Then, it was brought to the US once settled. Perhaps this was due to its compounds that help reduce inflammation, improve digestion, and help wounds heal.
Now, it’s a plant that most have seen but may not have been able to name. But, their tap root allows them to grow just about anywhere, including in garden beds, lawns, cracks in sidewalks, or even in compacted soils.
How to Get Rid of Plantain
Though potentially beneficial, the most haunting fact about plantains is their ability to produce 14,000 seeds per year. Additionally, their seeds can stay in the soil and be ready to sprout (given the opportunity) for more than 60 years.
Controlling these weeds is possible with hand-pulling, but you may want to ensure they won’t return with a neighboring plant to the one you pulled. In that case, choose a selective herbicide that will target broad-leafed weeds while keeping your lawn looking great. Bonide’s Weed Beater Fe is a great organic option for removing broadleaf plantain varieties. A more aggressive chemical option also includes Bonide’s Weed Beater (non-Fe), which is not organic and will target both broadleaf and buckhorn plantains.
As with most annual weeds, it’s possible to suppress the opportunity for new plants to germinate using mulch. Fall is a great time to apply it, but it can be helpful for weed suppression at any time during the growing season.
Landscape Weed #8: Purslane
Identifying purslane in your garden or landscape is typically easy due to its distinctive features. The reddish stems radiate outward along the ground from a single taproot. Those stems carry many succulent fleshy leaves and commonly have yellow flowers. (Though there are also a few less-weedy ornamental varieties that have other flower colors.)
Purslane is actually cultivated in gardens around the world due to its health benefits. In the mediterranean, many gardeners or chefs add it to salads or soups. In Mexico, it’s occasionally added to omlettes. Health-conscious consumers may also juice it or add it to smoothies. Why go through all this trouble for a common weed? Well, it offers seven times the beta carotene of a carrot, six times more vitamin E than spinach, and 14 times more omega 3 fatty acids than any other leafy land plant.
How to Get Rid of Purslane
Understandably, not all will want to harvest this weed and start adding it to our meals or snacks. What makes purslane so haunting is its succulent-type ability to create new plants from parts of old ones. The University of Illinois Extension offers this tongue-in-cheek description: “Running a tiller through purslane is called purslane multiplication.” So, manual removal may be an option to help control small populations.
However, purslane that is manually pulled and laying on the ground can still ripen its seeds and distribute them when disturbed. Or, if not picked-up, you’ve just helped purslane start a new crop.
To be sure the freshly cleared area is free of purslane going forward, try Bonide’s Weed Beater Fe. This is a great organic option for removing unwanted purslane. Also, try blocking existing seeds from germinating using mulch.
Landscape Weed #9: Thistle
Thistle plants (specifically, Canada Thistle in Northern Illinois and Chicagoland) seem to pop up just about anywhere and everywhere. They grow in gaps between sidewalks or curbs, in lawns, in garden beds, and more.
These perennial weeds have creeping roots and prickly-edged leaves. The oblong leaves, sometimes similar in appearance to some lettuces are irregular in shape and appear crinkled. The top of the leaf is a dark green, and the underside is light green and a little hairy. The stalk is surrounded by each leaf, making the stem feel spiny too. These plants can grow as much as five feet high and end in flowers that develop wind-carried once dry.
How to Get Rid of Thistle
Many regard thistles as one of the most feared species due to their ability to quickly establish entire colonies of plants. Colonies can extend several feet across due to their rhizome-like root system. Because of this, it’s considered a noxious weed by Illinois law due to its ability to impact natural areas.
Small populations may be controlled by hand-pulling. But, larger populations may require herbicide use. Bonide’s Weed Beater Ultra product in a ready-to-use spray or concentrate can be effective when used according to the label.
Landscape Weed #10: White Clover
White clover is easily identifiable due to its leaves being a common shape to most schoolchildren. This variety develops tiny white flower stalks that sit a mere inch or so above the leaf cover.
Just like chickweed, white clover is a weed that has the potential to offer a benefit. Clover can help a gardener identify areas of a lawn or garden bed that need more nitrogen in the soil. This plant is actually a legume that converts air nitrogen into plant-consumable nitrogen. White clover even used to be included in grass seed because of this (though, it’s not a common practice today).
Many homeowners, however, see a clover-filled lawn as weedy and look to eradicate it.
How to Get Rid of White Clover
While it’s easy to manage clover populations with hand-pulling or herbicides, the more difficult element to control is their seeds. The GardeningKnowHow blog describes the seeds: “The seeds can survive high heat, low temperatures and can stay dormant for years before germinating. Whichever method you choose for getting rid of white clover, you can expect to be doing it once a year to control the white clover plants that emerge from the seeds.” In garden beds, seed germination opportunities can be greatly lessened with a thick layer of mulch.
If you’re looking for a chemical treatment option, try Bonide’s Chickweed Clover & Oxalis Killer, available at Platt Hill Nursery.
Platt Hill Nursery is Chicago’s premier garden center and nursery.