Lawn Weed Identification: With Photos and Descriptions of Weeds


If you have a lawn, you have nearly definitely had to combat weeds growing in your grass. As they have adapted to become enduring, fast-growing, and overall, a downright pain to remove, there are a lot of things you need to know to properly remove, eliminate and prevent weeds from coming back.

This article will teach you all you need to know about identifying weeds that have sprung up in your lawn, and how you can then effectively clear them. 

Lawn weed identification

Weed Categories

First things first, you need to know your weed categories and understand what type of weed they are so that you can identify them and address the problem to prevent resurgence. There are two main broad categories that weeds fall into:

  • Grass-like weeds
  • Broadleaf weeds

But, just to complicate things, within those categories there are sub-categories of weeds:

  • Annual weeds = which grow from seed every year, produce and spread their own seed, and then die off at the end of the growing season. 
  • Perennial weeds – which is where the same plant comes back year on year. 

This article will look at all four types of weeds, i.e., both perennial and annual grass-like weeds, as well as both perennial and annual broadleaf weeds. After reading this article, you will be able to identify the weeds in your lawn, as well as effectively remove them long-term. 

Why Are Weeds So Bad for my Lawn?

They seem to spring up rapidly, and spread even faster, but why do we dislike weeds so much, and why are they so difficult for any amateur gardener to eradicate. 

Often, they’re leafy green and lush looking, and might even fit in well with other plants in your garden – but weeds are a lot different from the grass we have in our lawn. They have adapted to drain the soil of its nourishment and can have an impact on even the best looking, softest, and most uniform lawn. 

If left untreated, the weeds will totally take over your lawn, suffocate your plants, and make your lawn look straggly, thin, patchy, and ugly. Your lawn grass is not as hardy, tough, or resilient as the common garden weeds, and will come out of a weed infestation far worse for wear. 

There are a few conditions that make it easy for weeds to spring up, such as mowing your lawn too much, watering the grass too shallowly, improperly fertilizing, and poor soil conditions.

If you think that you have inadvertently cultivated a lawn full of weeds, then the reason for our extensive guide to types of weed, so we can help you find out what kind of problem you have in your lawn, and how to resolve it. 

Why is Lawn Weed Identification so Important?

Before you jump in all gung ho, and strip every single non-grass plant from your lawn, it is essential that you know that not all weeds will harm the plants in your garden or your turfgrass.

An example of a beneficial weed is clover (more officially known as yellow clover or black medic weed), which is a legume. These types of plants naturally turn air into nitrogen, which they then deposit in the soil. This means that the soil is enriched, and in turn feeds your plants. In spite of these benefits – most homeowners still want it gone from their lawns. 

With so many types of weeds, some of which are beneficial, it is crucial to know how to identify all of the different lawn weeds, so that you can combat them with a long-term fix. If you use the wrong product, you could harm your lawn’s mini-ecosystem, and end up killing your grass rather than the weeds. 

Common Types of Lawn Weeds 

You have probably seen all of the weeds that we will include in this list – whether in your lawn, on pathways, or at the parks, you just might not have realized what they were, or not had names to put to them. 

As we have already covered, some types of weeds are annual, dying off after living just one season, whereas others are perenials, which grow back when the weather changes every spring. 

Below, we have listed all of the common types of weed you are likely to find in your garden, broken down into sections by their foliage type, seasonal patterns, life cycles, and control methods. 

Broadleaf Lawn Weeds 

These weeds are identified by the unique shape of their leaves. They do not resemble grass, meaning they are some of the easiest to identify when they are in your lawn. 

1. Annual Broadleaf Lawn Weeds

  • Carpetweed (also known as chickweed and devil’s grip)= these plants, in the Mollugo verticillata family, are tropical and subtropical, which some botanists believe originated in tropical America.  It tends to be found in frequently disturbed areas, like a well mown/scarified or newly planted lawn, a much tilled garden, or alongside pathways, roads, and railways.

Carpetweed is usually found in dry, sandy soil, but can also thrive in more moist conditions. It does not compete well with plants that are taller, as it gets shaded out.

Regardless of its tropical heritage, it is now naturalized throughout all of America. You will see the summer annual germinate later in the spring, once the soil is a little warmer. Much as its name suggests, carpetweed will grow rapidly across the ground and form a mat, that stretches to about 2 feet across. 

To control this weed, you have to pull them out by hand, or with tools. So long as they are caught early on, hand pulling can be exceptionally effective, but if you see larger mats of the weed it is probably a better option to use a chemical weed killer to treat it.

Herbicidal treatments for carpetweed are 2,4-D, MCPP, Dicamba or Triclopyr. Before use, ensure that you have read all of the instructions carefully, and follow all of the necessary safety procedures. 

  • Common Lespedeza (which can also be known as Japanese Clovers) = this weeds is a summer broadleaf annual weed, that, like carpetweed, grows into a wide mat that tops out at around 15 to 18 inches wide. It can be very wiry, and almost bush like, especially when a few Japanese clover plants are grouped together.
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They grow low on the ground and will suck nutrients out of the soil, resulting in smothered grass if it is left untreated. In appearance, common lespedeza has dark green colored trifoliate leaves (arranged in clusters of three). The leaves themselves are oblong and smooth in shape, with parallel veins approximately 45 degrees from the more prominent mid-vein.

It flowers in late summer, producing single, tiny pinky-purple flowers. Areas of thin, under fertilized turf and poor soil, are particularly susceptible to Japanese clover. 

To control the growth of Japanese clover, you can start mechanically pulling them out with your hands or a tool. It is best to pull them up when the ground is moist, as working the tough, deep roots out is easier. This will work well for a small infestation, or on young weeds, but might be more difficult if it is a bigger cluster of well-established plants.

You can also spread 2-3 inches of much over the top, which will prevent future seed germination, although this is likely only an option if you have found them in flour or veg beds. If you would prefer to use herbicide, Speedzone, 2,4-D MCPP, Dimension Ultra, Dicamba and many others will help. Our personal preference is Southern Ag’s herbicide for broadleaf weeds.

We would like to remind you though that herbicide is a last resort, and you should only use chemical treatments as a last resort – as they have a myriad of potential risks for you, others, animals, the environment, and all of the other plants you have in your garden. If you have weeds in your lawn, you will have to spot weed kill them, to avoid killing off large chunks of your grass. 

  • Knotweed (we are specifically looking at prostrate knotweed, Latin name polygonum aviculare) = knotweed is an annual plant (though occasionally it slips into the short-lived perennial category), that is often found in gardens widely distributed around the US. They are spread by small brown seeds and require a period of enduring cold and moist weather in order to germinate.

After this, seeds will germinate, and tiny succulent-like seedlings emerge around late winter to early spring (and are usually one of the first plants to emerge in your garden). In their appearance, knotweed seedlings grow upright initially, with leaves that are lance or oblong shaped.

When they mature, the stems will slop over to form a mat, especially when you have mown it recently. They will also sprout branches, and take on a wiry texture, and exhibit longitudinal rib growth. It will sprout white flowers, with pinkish margins, which are all held in little clusters along the stem. 

To control prostate knotweed, you can pull it out by hand, whilst it is still a seedling if you spot it early enough, just be sure that you dig out the long, branching roots to make sure that you have dealt with it, or else the weed will continue to come back.

If you have had issues with knotweed in your garden, you can spread mulch over the garden beds, which will prevent any of the seeds from germinating. However, once it has already become well established in your garden, it is probably best to use chemical methods to eliminate the weed totally from your lawn.

Like many other mat-like prostrate weeds, to kill knotweed you will need herbicides like 2,4-D, MCPP, Dicamba, Triclopyr, Roundup, and Gallup, which can be purchased both online and in person.  

  • Prostrate Spurge = this weed is a commonly found summer annual broadleaf, that is one of the easiest to identify. It grows low to the ground, with dark green oval-shaped leaves that culminate in a soft point. A notable feature is their red stems, and the plant will grow very sweet looking tiny pink flowers.

The plant itself will grow outwards from where it initially comes up, protruding out in a very rough wagon wheel shape. Curiously, the whole plant also has a hair appearance. Together, these physical characteristics make spurge an easily recognizable weed. 

  To control an infestation of prostrate spurge, like many other broadleaf weeds, can easily be pulled out by hand. It can be a little time-consuming, but does bypass all of the risks that are associated with using chemical herbicides. As we have already established, moist soil will provide a better result when weeding, as the roots will come out.

If growth is a little more advanced, then herbicides could be the best course of action for more substantial spurge infestations in your lawn. We recommend you use Ferti-Lome Weed-Out, Dismiss Turf, MCPP, and other herbicides that are also effective against Spurge.

2. Perenial Broadleaf Lawn Weeds

These perennial varients require more aggressive tactics if they are to be controlled – otherwise they will take over your lawn, coming back year after year. 

  • Buttercups = the recognizable yellow flowers, though cute looking, are simply masquerading as a decorative plant. They are actually a summer perennial lawn ruiner. These plants are some of the easiest to identify on the list – the yellow flowers have five to seven petals, which are grown on individual stems that rise vertically.

They aren’t quite as invasive and life-sucking as their cousin, lawn ivy (which has purple or white flowers rather than yellow), though they do spread in much the same way, and detract from a plush, uniform green lawn that many lawn care enthusiasts are desperate to achieve. 

If you want to try to control an outbreak of buttercups in your lawn, you have to get all of the roots out of your lawn. Your best bet is it pull them out by hand, when the soil is moist, though do take care, as the bulb like root can make it quite difficult to fully pull them out of the ground.

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If you want to take the chemical path, then you can use nearly any broadleaf weed killer to eradicate buttercups (or lawn ivy) from your grass, nearly all of the broadleaf weed killers will work. Particularly 2,4-D, MCPP, Dicamba, Scotts Ortho Weed-B-Gon herbicides will be effective.

  • Dandelions – this is really the poster child for common lawn weeds – it’s durable, it springs up all over, and the long taproot is a nightmare to get out. You will be familiar with it, but in the small chance that you are not, they have a yellow flower, and sometimes can masquerade as mini sunflowers, and are pretty popular with pollinators like bees and butterflies. They do spread like wildfire, though, with each plant releasing an airborne 15,000 seeds every flowering season. 

To control dandelions, your best bet is to uproot them whilst the soil is damp. The taproots (if you aren’t familiar, think a rough mini carrot) are both a blessing and a curse – it can make it easier to pull up, especially when the plants are young, but it can be a challenge to get the whole plant root out of the ground when the dandelions become more established, which will let them regrow.

Herbicidal treatment is also difficult when dealing with dandelions. A pre-emergent herbicide can keep them from germinating come spring, giving you a little head start on your lawn upkeep. We recommend the use of Pennington Ultra Green Weed and Feed 30 – 0 – 4, to suppress any initial dandelion growth, or any of the previously mentioned broadleaf killing options will work for spot treatment. 

  • Broadleaf plantain = this plant has a short stalk, with flat, broad leaves. The leaf has five veins at the base, which makes broadleaf plantain distinctive and easy to identify when it sprouts in your lawn. The flower grows upwards, and has a nearly prickly look to it, though really the petals are soft.  

If you have compacted soil, or don’t fertilize enough, you will be particularly susceptible to broadleaf plantain. If you have an enduring problem with them, it might be useful to fertilize and aerate your turf, which will discourage its growth in the more long term.

To control broadleaf plantains, you will have to start with hand pulling – this can be a challenge, though, as the leaves grow flat to the ground. There are a few tools that you can utilize to help you pull them up, though – such as the Fiskar’s Stand Up Weeder, which will easily uproot these weeds.

These tools work particularly well if you have only a few weeds in your lawn, and don’t mind dedicating a quarter of an hour a weed to pulling them out manually. Alternatively, if you’d like to deal with them chemically, you can use herbicides like weedkiller Roundup, Hi-Yield Ferti-Lome, Broadleaf Weed Killer, 2,4-D, MCPP, and plenty of other options. 

Grassy Lawn Weeds 

3. Annual Grass-Like Lawn Weeds 

  • Bluegrass = contrary to its cousin Kentucky Bluegrass, which is one of the most widely popular types of grass for turf in the US, the stringier, summer, annual bluegrass is considered as a weed. The annual weed version of bluegrass can grow to a giant two feet tall, and its grass blade-like leaves can make it tough to differentiate between it and types of other grass in your turf.

Though it might sound as though it won’t be too much of an issue if it cannot be differentiated from your normal turfgrass, annual grasses are an issue because they are very aggressive, and will crowd out your lawn grasses. Eventually, this will create a scraggly, patchy lawn that is susceptible to countless amount of other weeds. 

To control an outbreak of bluegrass, you can pull the weed up by hand, which will be effective (though hard word, due to their deep roots), just ensure that you do it wearing gloves, as they can cut your hands. Once you have hand-pulled a population of bluegrass, then you should cut the lawn to around 3-4 inches tall, which will prevent further growth, as seed heads cannot form.

You can also use herbicidal weed killers on annual bluegrass, such as Pylex Herbicide, Selective Weed Killers, or Treflan. Our recommendation is a combined method of control – apply a good pre-emergent herbicide in the spring, which will allow your lawn grasses to crowd and smother any possible sprouting of annual bluegrass, as bluegrass germination will be delayed.

Then, if any seedlings do manage to get through, so in with your gardening glove to uproot them before their seed heads get a chance to form. The organic pre emergent herbicide from Jonathan Green is good for this, as not only is it effective, it is also safe for children, animals, and insects. 

  • Crabgrass = this is one of the most notorious of lawn weeds, as it spreads voraciously and is an absolute headache to get rid of. It is a stringly looking summer annual grass that will sprout along your turfgrass every spring. Crabgrass is distinctive for its narrow leaves, which protrude from a flat, fringed plant stem.

It is usually quite easy to an infestation of this weed, as it has a much lighter color than turfgrass. As each plant can produce 150,000 seeds in a single season, it is not shocking that once you have one weed, your lawn will be teeming with them in a few weeks. It is one of the most important weeds to identify and eradicate quickly, as if left untreated, within a few years it will take over and completely smother your lawn. 

 To control crabgrass, the best course of action is probably rapid identification, and spot treatment using a grassy weed killer, like the herbicides Pennington UltraGreen Crabgrass Preventer, Pylex Herbicide, Selective Weed Killers, and Treflan. You can try to hand pull it out, but this is difficult and pretty labor-intensive, as with many grassy lawn weeds.

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Due to how painful it is to deal with infestations of crabgrass, the market is filled with new and innovative products that will help homeowners deal with the grass.

We recommend that you use tried and tested ‘Scott’s starter fertilizer and crabgrass preventer’ spread in the early spring – with this one, you get what it says on the tin, and it will give you a thick lawn whilst suppressing the growth of crabgrass. Other pre-emergent products might block your turfgrass seeds from germinating, but thankfully this one doesn’t 

  • Goose grass = this weed is a stringly looking, summer-growing annual, then grows to a very large two feet tall if left untreated. In appearance, it has grass blade-like leaves, but its distinctive feature is that it spreads out from the base, in much the same way as crabgrass, rather than sending up individual blades of grass through the soil.

Because of this, it will damage all of the desirable grasses in your lawn rapidly and has to be dealt with speedily. 

**To deal with goose grass, we recommend all of the methods that we have discussed already in regard to crabgrass. Goose grass will respond to preventers and pre-emergents just like crabgrass does, so you can keep them both under control on your property at the same time. 

4. Perennial Grassy Lawn Weeds

Though grassy annuals get the most attention (and generate the most fear) from homeowners, perennial grass weeds can cause really big problems for lawn lovers over time if they are left untreated. 

  • Dallisgrass = this lawn weed is pretty easy to identify, as some of its growth habits are unique. It grows in grassy clumps, that will spread throughout your lawn if you don’t deal with them. The grassy leaves themselves are a yellowy green in color, and are about half an inch wide.

They are quite short grasses, usually growing between one and three inches tall. The concern with dallisgrass is that if you have a patchy or poor-quality lawn, it can easily blend in.

The way to identify dallisgrass if you think your lawn falls into one of these categories, to look in your lawn a few days after you have mown. Dallisgrass grows faster than other types of grass, and will noticeably protrude a few days after you have mowed, whilst the rest of your law lags behind a little shorter.  

**To control dallisgrass, you can use most pre-emergent treatments that work on crabgrass, which will be especially effective against dallisgrass when you have a thick lawn to crowd it out. If you have a thinner lawn, post-emergent herbicidal spot treatments might be the route to take.

Herbicides like Pennington UltraGreen Crabgrass Preventer, Pylex Herbicide, Selective Weed Killers, and Treflan all work well on this weed. Hand pulling is labor-intensive, because of its deep roots, but possible. If you have repeated emergence of dallisgrass, your lawn could be suffering from poor drainage, so see if you can fix that issue to prevent long-term regrowth. 

  • Nimblewill = if you have this weed in your lawn, you should be able to tell what it is right away – it is different in appearance from crabgrass, and most of the other grass-like weeds, but you will still be able to differentiate it from the rest of your lawn.

It tends to look stringy and clumpy when compared to the rest of your turfgrass, and will develop in color slower than the rest of your lawn, making it easily spottable in grassy pastures and lawns.

You will usually see nimblewill growing in shady areas on your lawn, and because of this is usually one of the first grasses to go brown in hot sun or heat (as it is simply not used or equipped to deal with the hotter temperatures. You can use this fact to help you spot nimblewill in the summer! 

**To control nimblewill, as with all grassy annuals, hand pulling the weeds will always be effective – just make sure that you totally uproot the nimblewill, or else it will come back. Having a healthy lawn can also help to deter nimblewill, preventing it from germinating and spreading, so keep your grass happy by fertilizing and mowing.

Alternately, you can use chemical herbicides such as Pennington UltraGreen Crabgrass Preventer, Pylex Herbicide, Selective Weed Killers, and Treflan to control nimblewill. 

  • Quackgrass = this is a distinctive annual lawn weed, notable for its height (it can grow to a gargantuan three feet tall) and unique blue-green color. The leaves themselves are thin and have a rough texture.

It looks like a lot of the ornamental grasses that can be found in your local garden center. Don’t be fooled, though – it is destructive, and can wreak absolute havoc on your beloved lawn if left unchecked. 

**To control quackgrass, we suggest that you stay on top of your lawn care, and apply a crabgrass preventer in the early spring months, which will act as a catch-all killer for grassy weeds in your lawn.

Final Thoughts: Identifying the weeds is only the first step… 

Most of these weeds, regardless of whether they are broadleaf or grassy, can be controlled in a very similar manner, that is universal across their specific categories. After you have used this guide to help you identify any weeds that have sprung up in your turf, you will need to act quickly to treat and eradicate them from your lawn.

Otherwise, weeds (especially perennial ones) can gain a foothold in your grass, and become impossible to remove in the long term. 

Remember to stay safe when you are using herbicides and pre-emergence treatments; always read the product’s instructions before you use them, and wear protective equipment to keep yourself safe.

Follow all of the manufacturer’s directions to keep yourself, your kids, your pets, and the rest of your garden plants safe, and keep a close eye on the weather, so that you maximize the effectiveness of weed treatment the first time.