Unraveling the Mystery: The Various Kinds of Crabgrass

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Closeup of crabgrass that has overtaken a lawn


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Crabgrass is a common weed that plagues lawns and gardens worldwide. There are many different types of crabgrass, each with its characteristics and habits.

In this blog, we will explore the various types of crabgrass , so you can recognize them and take appropriate steps to eradicate them from your landscape.

Whether you’re an experienced gardener or a novice lawn enthusiast, understanding these different types of crabgrass can help you maintain a healthy, beautiful outdoor space.

So let’s dive in and discover everything you need to know about the different varieties of this pesky weed!

Closeup of crabgrass that has overtaken a lawn

Introduction to Crabgrass Species

One of the most common lawn weeds is crabgrass, which belongs to the genus Digitaria. Crabgrass is an annual grass species reproducing by seeds that can become easily dispersed due to foot traffic and maintenance equipment.

There are nearly 35 species of crabgrass, but the two most commonly found in North America are smooth and hairy crabgrass. Another species, southern crabgrass, can be found in warm southern regions.

It’s essential to understand the different types of crabgrass to identify and manage them effectively.

So, as we dive deeper into the physical characteristics and comparison of the three species, you will learn how to identify them and avoid common mistakes.

Physical Characteristics of Crabgrass

After learning about the different types of crabgrass, it’s crucial to understand their physical characteristics to differentiate them from other grasses.

Crabgrass has thin, sprawling stems that resemble crab legs, and is typically light green in color. Smooth and large crabgrass, the two most common species in North America, have short membranous ligules, with jagged tips for large crabgrass.

Crabgrass plants can range from a tall 10 inches to 1-2 inches if frequently mowed or growing in unfavorable conditions.

Multiple tillers contribute to the clumpy appearance of crabgrass. While similar to other grasses like quackgrass, foxtail, and dallisgrass, knowledge of a crabgrass plant’s jagged ligule can aid identification.

Understanding the distinct physical characteristics of crabgrass is vital for prevention and control of their growth in lawns.

Common Crabgrass Species in North America

When it comes to crabgrass in North America, the two most common species are the smooth crabgrass and hairy crabgrass.

These types of crabgrass can be easily identified by their physical characteristics. Smooth crabgrass is small, with stems that lie close to the ground, while hairy crabgrass has thicker stems that can grow up to 2 feet tall.

Another species of crabgrass found in the southern United States is southern crabgrass. Though less common than the other two species, it can still cause problems for homeowners.

It’s important to understand these different types of crabgrass to identify them and prevent their spread accurately.

Species 1: Hairy Crabgrass

Hairy crabgrass, also known as Digitaria sanguinalis, is one of the most common crabgrass species found in North America.

This species is easily identifiable by its long, coarse hairs on the leaf blade and sheath, which gives it a hairy appearance.

Hairy crabgrass can grow up to 3 feet tall and has a spreading growth habit. It prefers areas with full sun to partial shade and is often found in lawns, gardens, and agricultural fields.

It is also known to be a significant weed problem in these areas, as it can quickly dominate and outcompete desirable grass species if left untreated.

Understanding hairy crabgrass’s physical characteristics and growth habits is crucial in preventing and controlling its spread in lawns and landscaping areas.

Species 2: Smooth Crabgrass

Species 2: Smooth Crabgrass is a warm season summer annual grass that commonly infests lawns, golf course turf, athletic fields, parks, and institutional grounds.

It is found in many habitats, such as small fruits crops in New York State, and other landscapes.

Smooth crabgrass may be mistaken for other types of grasses, but it’s identifying characteristic is its flattened stems that grow horizontally along the ground, with alternating leaves that are light green in color.

This crabgrass species can be controlled through proper lawn maintenance practices such as regular mowing and timely application of pre-emergent herbicides.

Prevention is also key, as smooth crabgrass thrives in areas that are not well-irrigated or where soil nutrition is poor.

By understanding the different types of crabgrass and implementing preventive measures, lawn owners can keep their lawns healthy and free from weed infestation.

Species 3: Southern Crabgrass

Southern crabgrass is an annual warm-season grass that grows up to 3 feet tall. This type of crabgrass is similar in appearance to the other species commonly found in North America, but its leaves are wider and coarser.

Fortunately, control methods for southern crabgrass are generally similar to those used for other types of crabgrass.

In addition, lawn owners should be aware that this species can easily be mistaken for other weed grasses such as quackgrass, foxtail, and dallisgrass.

Any of these species can cause problems for lawns and gardens, so it’s important to know how to identify them and take action before they have a chance to spread.

Homeowners can keep their lawns and gardens healthy and beautiful all year round by understanding the different types of crabgrass and other weed grasses.

Comparing the three species

When it comes to the most common species of crabgrass in North America, there are three that tend to be found in lawns: hairy crabgrass, smooth crabgrass, and southern crabgrass.

Comparing these three types of crabgrass involves looking at a few key characteristics. Hairy crabgrass and southern crabgrass tend to have wider blades than smooth crabgrass, which has blades that are narrower and shorter.

Hairy crabgrass is also typically larger than the other two species and has a more upright growth habit.

Regarding growth patterns, southern crabgrass tends to emerge later in the season than the other two.

All three species of crabgrass can be challenging to control, but understanding their differences can be helpful when considering prevention and control measures.

Identification of Crabgrass

Identification of Crabgrass is crucial to prevent it from damaging lawns and garden beds. Crabgrass is a weed that can grow in almost all types of soil and climates.

The key identifier of crabgrass is its membranous ligule and stiff hairs on the blade and sheath.

Crabgrass has two different types, smooth and hairy, which their physical appearance can distinguish. Smooth crabgrass generally lacks hairs on the stem and sheath, while hairy crabgrass is identifiable by its longer hairs.

Southern crabgrass has wider blades and grows faster than the other types of crabgrass.

It is essential to accurately identify which type of crabgrass invades the lawn before deciding on the appropriate control method.

Quackgrass, foxtail, and dallisgrass are some of the weed grasses often mistaken for crabgrass.

Types of Weed Grasses Often Mistaken for Crabgrass

In addition to crabgrass, there are several types of weed grasses that can be mistaken for this common lawn invader.

Quackgrass, foxtail, and dallisgrass are all often confused with crabgrass due to their similar appearance.

Quackgrass, a fast-growing perennial, is frequently mistaken for its annual twin due to its similar appearance.

Foxtail, on the other hand, has spiky seed heads that appear similar to those of crabgrass. Dallisgrass, a coarse perennial with deep roots, can also be an issue for homeowners.

Understanding these other types of weed grasses is essential for properly identifying and treating all lawn invaders.


Quackgrass is often mistaken for crabgrass due to its wide-bladed appearance, but it’s actually quite different.

As a cool-season perennial with deep-lying roots made up of rhizomes, quackgrass can be especially difficult to eliminate from lawns as it doesn’t die off each season like crabgrass.

It’s essential to identify the clasping auricle on the leaf blade that wraps around the stem to differentiate it from other weed grasses properly.

long with quackgrass, other types of weeds often mistaken for crabgrass include foxtail and dallisgrass.

Understanding the differences between these weed grasses can help with proper identification and effective control measures to ensure a healthier lawn.


Foxtail is another annual grassy weed that is often mistaken for crabgrass. It is a common invader of thin lawns and can easily be confused with its look-alike cousin.

Like crabgrass, foxtail has a distinctive seed head, but its leaves are typically shorter and thicker with a more bluish-green color.

Additionally, foxtail seeds have a bristly, brush-like appearance, which can help differentiate it from crabgrass.

While foxtail may not be as aggressive as crabgrass, it can still be a nuisance in lawns and gardens, especially if left untreated.

As with most weeds, prevention and regular maintenance are key to controlling foxtail.


Dallisgrass is another common weed grass that is often mistaken for crabgrass. It is a taller and more upright weed with thick, coarse leaves.

Dallisgrass also grows rapidly under nitrogenous fertilizers, making it a prolific weed in over-fertilized lawns.

Like crabgrass, dallisgrass can be identified by its bunched-up appearance and clumpy growth pattern.

It is important to differentiate between these two weeds because controlling dallisgrass requires a different approach than treating crabgrass.

Fortunately, various preventive measures and treatment options are available to combat both crabgrass and dallisgrass and keep lawns looking healthy and lush.

Effects of Crabgrass on Lawns

When it comes to lawns, crabgrass can have a significant impact. These invasive grasses compete with desirable grasses, spreading quickly and overtaking lawns.

Crabgrass grows closely together, creating a dense mat that can suffocate surrounding plants.

Additionally, crabgrass can be unsightly , detracting from the aesthetic appeal of a lawn. Prevention and control measures are crucial to keep crabgrass from taking over.

Mowing regularly at the right height, fertilizing appropriately, and watering properly are all steps to take to promote healthy grass growth and discourage crabgrass.

Additionally, selective herbicides can be used to target and kill crabgrass while leaving desirable grasses unharmed.

By understanding the effects of crabgrass on lawns and taking preventative measures, homeowners can maintain a lush, green lawn all season long.

Prevention and Control of Crabgrass

To prevent and control crabgrass, it’s important to establish a healthy stand of turfgrass in your lawn.

This can be done through regular watering and fertilizing and mowing to the appropriate height for your grass variety.

Additionally, the use of preemergent herbicides can help to prevent crabgrass seeds from germinating.

Selective post-emergent herbicides, such as Quinclorac, can also be used to control crabgrass that has already emerged.

However, following application instructions is important to avoid damaging your desired turfgrass carefully.

Maintaining a thick, healthy lawn is the best defense against crabgrass and other invasive weeds.

What are the different types of crabgrass and how do they differ in terms of causes and effects?

There are two main types of crabgrass: smooth crabgrass and large crabgrass. Smooth crabgrass thrives in cool, moist conditions, while large crabgrass prefers hot, dry climates. Both types choke out desirable grasses and plants, leading to thin, patchy lawns. Understanding crabgrass causes effects is crucial for effective prevention and control.

Conclusion: Understanding the Different Types of Crabgrass

In conclusion, understanding the different types of crabgrass is vital for effective lawn management.

From the physical characteristics of the common species found in North America, it is clear that there are significant differences between them.

While they may all be considered turfgrass weeds, their unique attributes can affect their growth and spread.

Identifying crabgrass can be challenging, given its similarity to other weed grasses like quackgrass, foxtail, and dallisgrass, but it can be managed effectively with proper knowledge and tools.

By preventing and controlling crabgrass, homeowners can maintain a healthy, lush lawn free from this pesky weed.