Annual Grassy Weeds
Identification and Control
– Crabgrass and Foxtail Weeds –
Let’s look first at crabgrass. Most grassy weeds are undesirable weedy grasses that germinate and grow in lawns, but can lower turf quality and appearance. These weeds do not have the characteristics or growth habits that produce a quality lawn.
Annual grass-type weeds are those that germinate from seed each year and die at the end of the growing season. Annual weeds are prolific seed producers since seed germination is the method of producing the next year’s generation of plants.
Crabgrass (Late Spring Annual Weed)
- One of the most common and troubling grassy weeds.
- Yellow-green to a darker blue-green in color.
- Can be prostrate or upright growing.
- Multi-branched stems. Large crabgrass roots at the nodes.
- One plant can produce over 150,000 seeds.
- It doesn’t make a good lawn because it doesn’t take off until late spring or early summer and dies with the first heavy frost.
- Plants start off sparse but increase in number and size by end of the year.
- Can be difficult to stop once they start growing.
The U.S. and Canada have many grassy weeds with crabgrass being one the most problematic. There are two major species of crabgrass: smooth crabgrass (also called small crabgrass) and large crabgrass (also called hairy or common crabgrass). Smooth crabgrass is found mostly in the northern half of the U.S. and large crabgrass is found throughout the U.S. and southern Canada.
All crabgrass varieties are summer annuals that must come back each year by seed. It is a full sun grassy weed and will only tolerate very light, partial shade. It will not grow in shaded areas.
Crabgrass was originally introduced into this country as a possible forage crop. However, it easily escaped cultivation and is now widespread throughout the country. It is one of the most common and problematic weedy grasses in home lawns. It is also found on golf courses, parks, flower and vegetable gardens, athletic fields and any other place that seeds are able to germinate.
Crabgrass is most at home in areas of thin or poor quality turf. The plants grow quickly and can cover an entire yard by the end of summer.
Crabgrass is yellow-green in color with short, wide leaves. While the seedling look similar to other plants, they soon begin to distinguish themselves. In young plants, like the one in the photo to the left, the leaves are twice as long as they are wide. These young plants begin by growing prostrate with three or four stems branching out in a starfish pattern. As the plant matures the stems will curve in an upward direction. Each plant can produce as many as 700 new tillers (new leaf blades). At full maturity, each leaf will grow to be a few inches long. Crabgrass leaves have tiny hairs on both sides of the leaves.
The roots are shallow and fibrous and do not reach the depth of many other grasses. Large (hairy) crabgrass will root at the nodes and can produce long stolons. Smooth crabgrass does not root at the nodes.
The shallow root system works in their favor by absorbing as much water as possible before it reaches the deeper rooted plants. Frequent, shallow watering will cause crabgrass to flourish at the expense of other grasses. Less frequent, deep watering is better for your turfgrass, but will not neccessarily hinder crabgrass growth.
The photo above is of a mature crabgrass plant, while the photo below is of common bermudagrass.
The leaves of bermudagrass are much finer and are darker in color. Crabgrass seed heads are finger-like spikes that resemble common bermudagrass seed heads. However, crabgrass seed heads are somewhat thicker.
There are usually three to seven spikes that can either be folded up like a funnel or spread out in a whorl pattern. Each plant can produce as much as 150,000 seeds a year. Crabgrass germinates from seed each year when soil temperatures reach 55 degrees for five consecutive days. The blooming of forsythia in your area closely coincides with the germination of crabgrass seeds.
Once the seed has germinated, crabgrass becomes difficult to control. Because of the prostrate growth habit, crabgrass can produce seed heads at mowing heights as low as ½ inch. Mowing your lawn at a height lower than is healthy for your particular grass will only benefit and encourage crabgrass growth.
Cultural Practices that Help Prevent Grassy Weeds
Crabgrass, like many there grassy weeds, do not like competition from turfgrass. Crabgrass grows best in poor quality lawns, lawns cut and maintained too short, lawns with disease or insects damage, and in high traffic areas. Lawns with thin or deteriorating grass will give the seed plenty of sun, heat and space for seed germination. A poorly maintained lawn will guarantee that you will have increasing problems with broadleaf and grassy weeds.
If crabgrass is a problem, avoid fertilizing in late spring and summer. Especially avoid applications of high Phosphorus fertilizers. Phosphorus is essential for seedling growth and will only promote crabgrass establishment.
The best method of keeping crabgrass and other grassy weeds out of your lawn is to build a thick, healthy, vigorously growing turf. The first step is to ensure you have the right grass type for your area. Increasing the grass thickness can be accomplished by overseeding, plugging or laying sod, proper fertilization and irrigation. Until the lawn thickens, grassy weeds will continue to be a problem.
It is also important to mow your lawn at the highest recommend level for your specific grass type. This will shade the soil and make germination more difficult. Many cool season turf grasses can be mowed at a height of 3 to 4 inches. Depending on your grass type, see the Cool Season Grasses or the Warm Season Grasses Warm Season Grasses sections of this site for helpful mowing and planting information.
You may find it necessary to use a preemergent herbicide to prevent the seeds grassy weeds and other weeds from germinating.
The most effective and proven method of preventing crabgrass from starting is to use a preemergent herbicide. I can’t stress this enough. If you want to prevent crabgrass from ever starting, you have to use a preemergent.
Preemergents are an added ingredient in many spring fertilizer. The bags will be labeled “with Crabgrass Control” or “Crabgrass Preventer”, etc. Make sure you spread the fertilizer at the correct nitrogen (N) level for your grass type. For help developing a sound fertilizer program, read the page on Developing a Fertilizer Program.
A preemergent must be applied before the crabgrass seeds germinate in spring. Again, it MUST be applied before they germinate with only one exception, the use of Dimension preemergent will kill the crabgrass at very early seedling stages. I will describe this in better detail below.
A preemergent (also spelled pre-emergent or pre-emergence) herbicide works by preventing cell division on young plants. A preemergent doesn’t actually prevent the seeds from germinating, as commonly believed. However, once the seeds do germinate, the chemical prevents the cells from dividing and the seed dies. In this way, the seeds are destroyed. An important note: Preemergents will have the same effect on most lawn grass seeds as well. Do not overseed directly before or within a few months after herbicide application or your seed may be ruined.
If you have waited too long and the crabgrass begins growing, preemergents usually have no effect. However, there is one product with the trade name “Dimension” (Chemical name: dithiopyr) that will give some control of seedling plants for a few weeks after emerging from the soil.
The effectiveness of some homeowner type preemergent herbicides is questionable. Some brands don’t perform as well as others. The effectiveness is also related to how it was applied, the amount and frequency of irrigation, amount of rain received, etc.
Keep in mind, if applied too early, the chemical can breakdown too soon allowing mid to late season seeds to germinate. Other chemicals have a short life span and it must be reapplied in mid-summer. Therefore, timing of the application is very important. Outside temperature and soil temperature are important. Remember, crabgrass germinates when soil temperatures reach 55 degrees for five days in the top inch of soil. It is okay to water after the preemergent has been put down, but don’t over water or water too frequently. Frequent, heavy irrigation or heavy rain places maximum stress on these herbicides.
For Established Weeds
Once the weeds are established, they are very difficult to control. Post-emergent herbicides labeled for grassy weeds will need to be used. Most products will require several applications for complete control. Products with MSMA or DSMA will control crabgrass as well as other weedy grasses. The Ortho company makes a product with these active ingredients. Add the correct amount of a “sticker/spreader” to the herbicide mixture for better adherence and absorption into the plant.
There is also the herbicide quinclorac under the trade name “Drive”. This is now available to homeowners and sold by Ortho under the name “Weed-B-Gon MAX Plus Crabgrass Control Ready To Use”. It contains other ingredients to help control broadleaf weeds as well.
The most popular preemergent for crabgrass and other grassy weeds is Corn Gluten Meal. Nick Christians, a turf specialist and university professor in Iowa, holds the patent.
Corn Gluten Meal is sometimes marketed as an organic weed killer for broadleaf and grassy weeds. Although it actually holds little or no weed killing properties it is, however, an effective preemergent. It works by robbing the moisture from developing germinated seeds and seedlings.
One main difference between chemical preemergents and corn gluten meal is the amount applied. Corn gluten meal must be applied between 10 to 30 lbs 1000/sq.ft. Generally, 20 lbs/1000 sq. ft. is the average for most lawns. Use more for severe weed problems. It does not require a license to use.
Timing is important and it must go down near the time that seeds will germinate. After application, irrigate the corn gluten and allow a drying period. This is critical for effectiveness because it must absorb the surface moisture. In wet climates, such as the north western U.S., corn gluten meal may not be as effective. A second application can be made in the fall.
Keep in mind, with corn being used as fuel for vehicles, corn gluten meal is rising in cost. Shop for the best price.
Learn From the Mistakes of Others: Spraying your lawn with a a non-selective herbicide such as Round-up, etc is not an effective crabgrass control. It doesn’t harm the seeds in the soil. Although it will kill all the grass and weeds it touches, the following year you will still have the problem with crabgrass and other broadleaf and grassy weeds that start from seed.
For lawns containing 50% or more weeds with thin or very little grass, a non-selective herbicide can be used if you plan on seeding or sodding soon after. Don’t wait too long to renovate or the weeds will become established and you will have to do it again. Each grass type has a preferred time of year when it should be planted.
Read labels carefully and follow all label instructions. Note that MSMA and DSMA are not recommended for St. Augustinegrass, centipedegrass or carpetgrass.
Yellow and Green Foxtails (Summer Annual Weed)
Foxtails are a summer annual grassy weed. They get their name from the seedhead that resembles a fox’s tail. They can spread quickly in sunny areas but less so in shade. The same preemergents that control crabgrass will also control foxtails.
- Grassy weeds with characteristic cylindrical seed heads.
- Yellowish-green to blue-green leaves.
- Seed heads are 2-3 inch.
- Reproduces from seed only.
- Difficult to control once seeds have germinated.
- You will start to see foxtails as soon as the crabgrass weeds are well-established.
- The same preemergent that stops crabgrass also stops foxtails.
Foxtails are a species of warm season, annual grassy weeds that starts from seed. It grows in full sun, but can tolerate very light, partial shade. It will not grow in shaded areas.
It develops from a fibrous root system and has a prostrate to upright growth habit. With mature plants, it is common to see the stems branching out at the base, remain prostrate for an inch or two and then curve upward at a 30 to 70 degree angle. Each plant can produce multiple stems that can easily grow twice the height of the leaves.
The coarse leaves are a yellowish-green to a darker blue-green color. They can grow to 12 inches long and up to ½ inch wide. The leaves are flat and smooth. The widest part of the blade is at the base. The leaves have small silky hairs on the upper surface near the base.
Foxtails are known for their characteristic seed head that has a foxtail-like appearance. The seed head is at the end of the stalk and usually extends several inches above the leaves. Mature plant can have a dozen or more seed heads and can produce thousands of seeds each year. Seeds germinate when temperatures reach 68 degrees and will continue germinating through most of the summer. Foxtails will die at the first killing frost.
Giant foxtail is another foxtail species that grows 2-5 ft tall, but it cannot take repeated mowing. For this reason, giant foxtail is rarely found in mowed turf. Notice that the seed head of giant foxtail droops, while yellow and green foxtail seed heads do not.
The primary way of preventing the establishment and spread of foxtail is to maintain a thick, healthy lawn. Maintaining your lawn at the tallest mowing height recommended for your grass type will help slow seed germination.
Consistent, weekly mowing to remove the seed heads before they mature will also go a long way to deter spread. If you have only a few plants growing in your lawn, try removing them by pulling them up. The plant has a fibrous root system, however, some plants will root at the nodes near the base of the plant.
If you have had problems before with foxtails, the best way to stop their development is with a preemergent herbicide. These preemergents are added to spring fertilzers.
The same herbicides labeled for crabgrass will work on many other grassy weeds, including foxtails. Preemergents are added to spring fertilizer and will be labeled “with Crabgrass Control” or “Crabgrass Preventer”, etc. Always check the label before using, however. Once the preemergent had been applied, moisture in the soil will activate it. Fertilizers need to be applied correctly in the amounts needed for your grass type and time of year. Scotts fertilizer brand as well as a few others are good homeowner fertilizers. Bargain brands may not give you the control over grassy weeds that you would like. Since fertilizer applicatons are based on the Nitrogen (N) needs of the grass you will need to know how much to apply. Click on the link for helpful information on Developing a Fertilizer Program.
Most preemergents are designed to last a few months before they begin to lose effectiveness. Not all active ingredients work equally well or have the same duration and homeowner varieties tend to last the least amount of time. This means that your timing will be very important. Important Note: Foxtails will germinate a few weeks to a month later than crabgrass. Something to remember when applying a preemgerent.
Once the seed germinates, the herbicide chemical stops cell division within the seed, so the plant never develops. As a result, the seed dies.
The preemergent herbicide label may list other broadleaf and grassy weeds that it controls. However, most are not very effective with broadleaf weed seeds.
For Established Weeds
Post-emergence herbicides will be needed once the foxtails have become established. The herbicides containing the active ingredients MSMA or MSDA are labeled for many grassy weeds, including foxtails. Read the label carefully and follow all label instructions. MSMA and DSMA are not recommended for use on St. Augustinegrass, centipedegrass or carpetgrass.
There is also the herbicide quinclorac under the trade name “Drive”. This is now available to homeowners and sold by Ortho under the name “Weed-B-Gon MAX Plus Crabgrass/Grassy Weeds Control. It is a “Ready To Use” formulation, meaning it comes already pre-mixed. It contains other ingredients including 2,4-D and Dicamba to help control broadleaf weeds as well.
Nimblewill Grassy Weed
Nimblewill is a grassy weed that resembles bermudagrass. It is most prominent when growing in cool season grasses. Find information on identification, growth habits, and control methods.
Winter Annual Broadleaf Weeds
With each spring comes a surge of winter annual broadleaf weeds. Here you will find valuable information about these difficult weeds including growth habits, photos, and measures that can be taken to control them.
Summer Annual Broadleaf Weeds
Many of the most problematic broadleaf weeds are annuals. Here you will find specific summer annual weed information, with weed names, photos and control methods.
Perennial Broadleaf Weed Identification Page 1
Click here for weed identification and control of common broadleaf perennial lawn weeds. This page has detailed information on Canada Thistle, Mouseear Chickweed, White clover, Dandelion, Field Bindweed, Ground Ivy, and Common Mallow.
Perennial Broadleaf Weed Identification Page 2
This page contains more perennial broadleaf weed identification and control methods. You can find detailed information on Buckhorn Plantain, Broadleaf Plantain, Red Sorrel, Wild Violets, and Common Yarrow.
Yellow and Purple Nutsedge
Nutsedge is a summer perennial grass-like weed. They can be particular problematic since they cannot be controlled by broadleaf weed herbicides. Click here for weed identification, growth habits and control methods.
Lawn Weed Identification: Photos & Descriptions of Weeds
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 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).
In this article I’ll profile the most common lawn weeds within all four groups (both 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.
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 actually turns air into Nitrogen and feeds the soil in your yard. 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.
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 Jonathan Green (Amazon link). It’s 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.