If you’re like most homeowners, you’ve had to combat weeds in your lawn. But to properly remove and eliminate weeds from your yard (and keep them from coming back), you need to know what kind of weeds they are, and how to treat them. In this article I’ll provide a guide to lawn weed identification so you can efficiently clear weeds from your lawn.
Getting to Know the Weed Categories
To identify weeds in your lawn, and address the problem so they don’t come back, you need to understand what type of weed you’re dealing with. To do this, you must first understand that there are 2 main categories that weeds fall into:
- Grass-like weeds, and
- Broadleaf weeds.
And within those two primary types of weeds, there are some sub-categories:
- Annual weeds (weeds that grow from seed every year and die at the end of the growing season), and
- Perennial weeds (weeds that come back year after year).
A third type of weed (less commonly discussed in the lawn care community) is the biennial weed. These are weeds that complete their growth over a two-year period. These weeds have taproots that must be killed or removed for lasting control.
In this article I’ll profile the most common lawn weeds within the four primary groups (perennial and annual grass-like weeds, and perennial and annual broad-leaf weeds).
At the end of the article you should be equipped to identify the weeds in your lawn (and effectively treat and remove them).
Weeds: Why We Hate Them
Those pesky little plant imitators that seem to grow endlessly despite all efforts to eradicate … are back!
Weeds are often green, leafy, and sometimes they fit right in with the rest of the grass we grow in our yards.
But weeds are different than grass – they suck the nourishment out of even the best-looking lawns and gardens, and crowd out the soft, uniform grass we all strive to grow in our lawn.
Left unabated, weeds will take over your lawn, suffocate your plants, and make your lawn appear patchy, thin, and ugly.
I often find myself wishing that turf grass was as tough and resilient as lawn weeds. But I guess if it was easy to maintain a perfect lawn, everyone would do it.
Mowing too often, watering shallowly, improper fertilizing methods, and poor soil conditions, are all ways inexperienced homeowners foster the perfect habitat for various types of weeds.
So let’s get into my guide to lawn weed identification so you know what kind of a problem you have in your lawn, and how to solve it.
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Why Lawn Weed Identification is Important
Luckily, not all weeds cause harm to your plants, or your turfgrass.
Clover is a good example of this … it’s a legume that fixes nitrogen in the soil, converting it to a usable form such as Ammonium and Nitrate. But most people still want it gone from their lawns.
Yellow clover (Black Medic weed) is an annual legume that acts in a similar way.
With so many different types of weeds knowing how to identify lawn weeds and combat each species in your yard is crucial if you’re looking for a long-term fix.
Use the wrong product and you could end up killing your grass, not your weeds.
Common Types of Lawn Weeds
You’ve encountered these different plants in many ways. Whether in your lawn, on the sidewalk, or at the park, weeds have made their way in or around your life and it’s time to break things down.
Some weeds are annual, dying off after one season, and others are perennials, which will grow back every spring.
Below are two types of weeds and some common species, broken down by their seasonal patterns, life cycle,in and control methods.
Broadleaf Lawn Weeds
Broadleaf weeds can be identified by the shape of their leaves. In general, weeds in this category do not resemble grass, and they are easy to identify and locate within your lawn.
To help with lawn weed identification, I’ll highlight some of the most common annual and perennial broadleaf weeds below.
Annual Broadleaf Lawn Weeds
These are the most common types of annual broadleaf weeds you may encounter in your lawn.
Some are small with little white flowers and others don’t bear flowers. These summer annuals spread through seeds and will germinate quickly as the soil beings to warm up.
Control Methods – You can pull these weeds out by hand or with tools. When caught early on, hand pulling can be very effective, but as the infestation of carpetweed in your lawn grows it’s best to use chemical treatments to eliminate it.
When maintaining your lawn keep the grass dense and healthy. Herbicidal treatments to use for Carpetweed are; 2,4-D, MCPP, Dicamba or Triclopyr. I recommend the Southern Ag herbicide (Amazon link) for Carpetweed.
Make sure to read the instructions carefully and follow all safety procedures.
Common Lespedeza (Japanese Clover)
Common Lespedeza is a summer broadleaf annual weed that grows to 15-18 inches wide.
Japanese clover is very wiry and almost bush-like when present in a grouping of weeds. They grow low to the ground and will quickly crowd out and smother grass if left untreated.
Dark leaves are met with three smooth leaves and a singular pink and purple flower. These lawn weeds grow in under-fertilized, poor, soil.
Control Methods – Hand pulling and weeding tools can be utilized to catch an early onslaught of Japanese Clover in your lawn. It can be difficult to pull, so I recommend waiting until the soil is moist.
If you find Japanese clover in garden beds, 2- to 3-inches of mulch can help prevent further seed germination. Herbicides such as; Speedzone, 2,4-D, MCPP, Dimension Ultra, Dicamba, and many more, will help.
Again – I’ve had luck with Southern Ag’s herbicide for broadleaf weeds, which you can find on Amazon.
Knotweed is a summer annual broadleaf that loves to smother turf grasses and destroy lawns.
These plants grow low, long, and wide, with stems that create a carpet-like appearance. Often dark and thin, these plants can produce small yellow or white flowers at maturity.
Control Methods – Prostrate Knotweed can be mitigated by hand-weeding early before it becomes established. You must dig out its roots to ensure they’ve been dealt with, or Knotweed will keep coming back.
In garden beds, mulch will deter seed germination, and once it’s established, your best bet is to use chemical methods to eliminate Knotweed in your lawn.
2,4-D, MCPP, Dicamba, Triclopyr, Roundup, Gallup, and many other herbicides you can buy locally or on Amazon will prove effective against this broadleaf lawn weed. There are natural methods of weed control you can try as well if you’re trying to stay organic.
Prostrate Spurge is a common summer annual broadleaf weed that is easy to identify. It grows low to the ground with oval-shaped leaves, making Spurge a distinct and recognizable weed.
Flowers aren’t developed on Spurge, but there’s often a red spot where a flower would be located when Spurge reaches maturity.
These weeds can be found in lawns, sidewalks, and cracks of cement blocks.
Control Methods – Prostrate Spurges, like many other broadleaf plants can be taken out by hand. This is a time-consuming approach, but you avoid the risks that come with spraying herbicides, and it’s what I recommend for small groupings of Prostrate Spurge.
The thick stems make it easy to grab and pull out, as long as the soil is moist.
Herbicides are a great solution to eliminate advanced weed growth and substantial infestations of Spurge in your lawn.
Ferti-Lome Weed-Out (Amazon link) is what I recommend, but Dismiss Turf, MCPP, and other herbicides are also effective against Spurge.
A summer annual broadleaf, Purslane grows well with other abundantly growing weeds, plants, and thrives in compacted soils.
Purslane weeds branch outward, as far as 3 feet out from the root.
Leaves are blue-green with no flower. The stem is thin, red(maroon), and visibly protruding. Purslane weeds grow by seed and can produce little yellow flowers at maturity.
Control Methods – Pulling purslane is a pretty easy way to remove individual plants. The process is similar to Prostrate Spurge, as the stem allows for a good grip. Pull this weed when the soil is moist for best results.
If you have a lot of Purslane in your lawn, you may decide to treat it with herbicides. Use Roundup, Montery LG 5600, Hi-Yield Ferti-Lome, MCPP, or Dicamba. Most broad-leaf herbicides will be effective, and many won’t impact the health of your lawn grasses.
The Southern Ag broadleaf weed killer (Amazon link) is my choice. It works really well on all broadleaf weeds. Just be sure to follow all safety recommendations when applying it to your lawn to kill Purslane.
Perennial Broadleaf Lawn Weeds
These perennial varieties need to be controlled aggressively, or they can take over your lawn, as they come back year after year.
A short stalk with broad leaves and five veins at the base makes it easy to identify Broadleaf Plantain in your lawn.
The flower shoots erectly and appears almost prickly but the flowers are soft.
Broadleaf Plantain looks almost like a badly unfolded cabbage, with dark leaves that are thick and leathery, and a tower head.
Low fertilizer application and compacted soils will foster a great environment for plantain weeds, so fertilizing your lawn and aerating your turf are effective at discouraging its growth in your yard.
Control Methods – Manual removal (pulling) of Broadleaf Plantain is more difficult than annual broadleaf weeds. The root goes deeper, and the leaves grow near to the ground which makes it more challenging to pull the root.
You can use tools like the Fiskar’s Stand Up Weeder to uproot these weeds – they work well if you only have a few instances of weeds in your lawn and don’t mind keeping on top of them manually once a week.
Chemically, you can use herbicides such as Roundup, Hi-Yield Ferti-Lome, Broadleaf Weed Killer, 2,4-D, MCPP, and others.
I generally encourage homeowners to take a manual approach for low instances of weeds, and use herbicides to spot treat large weed infestations.
Summer perennials weeds like Buttercup masquerade as decorative plants. I know my daughter loves to pick them, and she also loves to pick dandelions, so when she was very young I accepted their presence in my lawn for a while.
But identifying these lawn weeds is easy. Flowers bear 5-7 petals and hang on to individual stems that rise vertically.
Buttercups are not quite as invasive as lawn ivy (purple or white flowers instead of yellow), but spread in much the same manner, and detract from the uniform green lawn most homeowners hope to achieve in their yard.
Control Methods – Because it’s a perennial weed, you must get buttercup roots out of your lawn. The bulb-like root can make it a little difficult to manually uproot so do your best to take care and pull these weeds only when the soil is moist.
Chemically, you can use almost any broadleaf weed killer to treat buttercups or lawn ivy. 2,4-D, MCPP, Dicamba, Scotts Ortho Weed-B-Gon (Amazon link), and many other herbicidal treatments for broadleaf plants will be effective.
Probably one of the more common lawn weeds that we’re all familiar with is the Dandelion.
Sometimes these weeds are left alone due to their alluring appearance (I mentioned how my daughter loves to pick them). But they spread like wildfire.
The flower is yellow and they mask themselves as miniature sunflowers, which are popular with pollinators.
Perennial dandelions return every year and can spread rapidly by wind, releasing up to 15,000 seeds per plant.
Control Methods – You can uproot dandelions by hand while the soil is still moist. Tap-rooted plants, such as dandelions, allow for easier pulling (on young plants), but it can be challenging to get the whole taproot from an established Dandelion plant.
Try to mow your lawn at the proper height, and don’t mow your lawn too short, as this favors further weed growth.
Many homeowners who don’t wish to deal with Dandelions apply chemical treatments. A good pre-emergent herbicide application in the spring can keep Dandelions from germinating early and give your lawn a head start to crowd out weeds, and post-emergent herbicide treatments are effective at killing established Dandelions in your yard.
Pennington UltraGreen Weed and Feed 30-0-4 (Amazon link) is a good choice to suppress dandelions, and any of the broadleaf herbicides mentioned earlier in this article will also be effective against Dandelions. Or you can look at my full list of the best weed and feed for lawns to find the right product for you.
Grassy Lawn Weeds
Annual Grass-Like Lawn Weeds
While Kentucky Bluegrass is one of the most popular types of turfgrass in the US, stringy summer annual bluegrass is considered a weed.
Annual Bluegrass can grow up to 2 ft tall and its leaves make it difficult to differentiate between it and other turf grass types.
The problem with annual grasses is they are very aggressive, and will crowd out your perennial lawn grass. Over time, this will create a thin, patchy lawn that will host countless other weeds.
Control Methods – Hand pulling bluegrass is difficult, although effective, and should be done with gloves.
To prevent further growth, make sure the lawn is cut at about 3-4 inches to prevent seed-heads from forming, and over-seed any empty spots in the grass with a good perennial turfgrass.
Chemical treatments can kill annual bluegrass as well. You can use; Pylex Herbicide, Selective Weed Killers, or Treflan.
My recommendation is to control annual bluegrass seasonally by applying a good pre-emergent in the spring. This allows your lawn grasses to crowd out and smother annual bluegrass seedlings by delaying their germination every year. I like the organic pre-emergent offered by Espoma (Amazon link) or this one from Jonathan Green which also contains fertilizer. Both are effective, and safe for kids, pets, and beneficial insects.
Apart from Dandelions, there is perhaps no other lawn weed quite as notorious as crabgrass.
This stringy summer annual grass with narrow leaves that protrude from a flat fringy base is easy to spot due to its light color relative to most turf grasses.
These weeds can produce up to 150,000 seeds per plant in a single season. While it is an annual lawn weed, identification and eradication is important. If left untreated it will take over and smother your lawn in a few years.
Control Methods – Hand pulling crabgrass is difficult, as it is with most grassy lawn weeds.
Chemically, you can use; Pennington UltraGreen Crabgrass Preventer, Pylex Herbicide, Selective Weed Killers, and Treflan.
The market is saturated with crabgrass preventer products since it is such a common problem in lawns.
In my lawn, the areas where I struggle with crabgrass every year are near the road, where the blow scrapes the turf bare every winter.
I over-seed those sections of my lawn each spring, and use Scott’s starter fertilizer and crabgrass preventer. This allows me to grow a nice thick lawn there every season while blocking the crabgrass. A lot of pre-emergent products will block grass seed from germinating. This one doesn’t, and it’s one product I swear by.
Goose Grass is a stringy summer annual that can grow up to 2 ft. tall. With this growth potential you wouldn’t think that it would spread outward from the base like Crabgrass, but it does.
This growth habit makes it damaging to lawns as it will quickly crowd out desirable turf grasses in your yard.
Control Methods – Like the other annual grassy weeds, Goosegrass is difficult to pull by hand.
It responds to most crabgrass preventers, and pre-emergent treeatment of your lawn in the spring is the best way to get Goosegrass under control on your property.
Pennington UltraGreen Crabgrass Preventer, Pylex Herbicide, Selective Weed Killers, and Treflan all work well.
Perennial Grassy Lawn Weeds
While annual grassy weeds get most of the attention from homeowners, perennial grass-like weeds can cause big issues over time.
Here is how to identify 3 common perennial grass-like weeds.
Lawn weed identification of Dallisgrass is pretty easy as its growth habit is unique.
Dallisgrass is a perennial grass that grows in clumps which quickly spread across a lawn if untreated.
Leaves are yellowy-green in color and less than half an inch in width. They can grow from 1 inch to 3 inches.
Dallisgrass can easily blend in with real grass if you have a poor quality lawn, but it has a faster growth habit, and will noticeably protrude above your lawn in the days after mowing while the rest of your lawn is still shorter.
Some people confuse Dallisgrass and Crabgrass, but the width of this plant and its growth habit is different (the base of Dallisgrass is typically wider).
Control Methods – Dallisgrass can adapt to areas with improper drainage systems very well, so you’ll often find it in wet areas of your lawn. It’s tough to pull Dallisgrass by hand to remove it, so this can be a good punishment for kids who have misbehaved (cheap labor!).
Most crabgrass preventer pre-emergent treatments are effective against this perennial, but post-emergent herbicides might be necessary if your lawn isn’t thick enough to crowd it out.
Pennington UltraGreen Crabgrass Preventer, Pylex Herbicide, Selective Weed Killers, and Treflan will all work well.
If you have Nimblewill in your lawn, it will be easy to identify. It’s different than Crabgrass and most other grass-like weeds, but it also will stand out from your standard turf-grasses.
Stringy, and often clumpy, Nimblewill develops a littler slower in color, making it noticeably visible in grassy pastures and lawns.
Nimblewill prefers to grow in shade. This means it will often be the first grass to go brown in hot sun or heat. This is a helpful lawn weed identification trick for this grassy perennial intruder.
Control Methods – Healthy grass can deter grassy weeds from germinating and spreading, but when weeds are present you can always do the natural labor of pulling it by hand. That said, if Nimblewill roots are left, the weed will grow back.
Chemically, you can use most crabgrass preventers to control Nimblewill; Pennington UltraGreen Crabgrass Preventer, Pylex Herbicide, Selective Weed Killers, and Treflan.
You may have Quackgrass in your lawn. This is a stringy perennial grassy weed that can grow up to 3 feet tall.
The leaves of Quackgrass are blue-green in color and thin with a rough texture. It resembles a lot of ornamental grasses you can buy at the garden center.
Control Methods – Poor lawn maintenance is a haven for grassy weeds, and applying a crabgrass preventer early in the spring is the best way to keep grassy weeds under control in your lawn.
Lawn Weed Identification is the First Step
Most of these weeds, whether broadleaf or grassy, can be controlled the same way across their specific types.
After your lawn weed identification questions have been answered, it’s time to get after them and use the proper treatment to remove them from your lawn.
Act quickly, so you don’t allow these weeds (especially perennial weeds) to gain a foothold in your turf.
Remember – whenever you’re using herbicides, read the product details before use and wear protective equipment to keep yourself safe.
Follow the manufacturer’s recommendations to protect your kids, garden plants, and animals, and pay attention to the weather so your weed treatment is effective the first time.
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