What does Crabgrass Look Like? (Prevention, Identification, and Control Strategies for a Beautiful Lawn)

Have you seen tough grass with many leg-like stems that looks like a laid-down ocean crab? Crabgrass, a common weed that plagues lawns and gardens, is a persistent nuisance for many homeowners and gardeners. Its ability to quickly spread and dominate patches of grass can be frustrating. You may have seen this in your flower or vegetable garden, on a lawn, on a driving roadway, maybe even popped up through a crack in the garden sidewalk. This grass has a low laying down growth habit which helps this plant to survive from your common weeding activities like mowing. Mower blades cut other grasses and weeds as they are taller but cannot cut this crabgrass.
Crabgrass looks like a crab. This is also known as finger grass. Recognizing crabgrass is crucial in order to effectively control and prevent its growth.

picture of a crab grass plant that looks like a crab — Crabgrass- a grass that looks like a crab

Scientific name and family

Scientific name of smooth crabgrass is Digitaria ischaemum.
Scientific name of hairy crabgrass is Digitaria sanguinalis.

Family of crabgrass is Poaceae.

So, actually what is crabgrass?

Any plant of the genus Digitaria is commonly known as crabgrass. Crabgrass is a native grass of Europe but it is now seen all over the world. It was introduced in the USA as a forage crop in the 19^th century. I have seen crabgrass as a common weed in Bangladesh also.

There are both annual and perennial species in Digitaria genus. This grass has flattened leaf blades. Crabgrasses have long flower clusters and thousands of seeds are produced from there. You may find that some crabgrasses are much hairy and some are relatively smoother. The presence or absence of hairs is the main sign what helps in the identification of hairy or smooth crabgrass. If you look at them carefully you will find the differences easily. They are of two different species from the same genus. Normally, smooth crabgrass (scientific name- Digitaria ischaemum) is relatively smaller than the hairy one (scientific name- Digitaria sanguinalis).

Characteristics of Crabgrass

Crabgrass possesses distinct characteristics that set it apart from other grasses and weeds. By familiarizing yourself with these traits, you can identify and differentiate crabgrass from your desired turf. Here, we’ll delve into crabgrass’s appearance, growth habits, and life cycle.

a. Description of Crabgrass Blades:

Crabgrass blades are typically wider and coarser compared to desirable grass species. They exhibit a pale green to light yellow color and have a distinct V-shaped leaf structure. The blades also feature a prominent midrib running down the center.

b. Height and Texture Variations:

Depending on the specific species and growing conditions, crabgrass can vary in height. Generally, it tends to grow lower to the ground, forming a sprawling mat-like structure. The texture of the leaves can feel rough and coarse when touched.

c. Life Cycle and Growth Patterns

Annual Growth Cycle: Crabgrass is an annual weed, meaning it completes its life cycle within a single year. It germinates from seeds in the spring when soil temperatures reach a certain threshold. As the weather warms up, crabgrass grows rapidly and produces seeds, completing its life cycle before the onset of winter.
Rapid Spreading Tendencies: One of the defining characteristics of crabgrass is its ability to spread quickly and aggressively. It produces an abundance of seeds that can easily be dispersed by wind, water, animals, or human activities. Additionally, crabgrass has a prostrate growth habit, sending out long, sprawling stems that root at various points, allowing it to cover significant areas within a short period.

Identifying Crabgrass in Lawns

Identifying crabgrass early on is crucial when it comes to maintaining a healthy and lush lawn. You can take appropriate steps to control its growth by differentiating it from other grasses and weeds. In this section, we will discuss the key differences between crabgrass and desirable grasses and visual cues that can help you recognize this persistent intruder.

a. Differences between Crabgrass and Other Grasses

Leaf Shape and Color Variations: Unlike desirable grasses, crabgrass leaves have a distinct V-shaped structure with pointed tips. They are wider, coarser, and lighter in color compared to the surrounding turf. When closely examined, you may notice fine hairs on the leaf blades.
Growth Patterns and Density: Crabgrass often grows in clumps or patches rather than forming a uniform, dense turf. It can create a disheveled appearance amidst an otherwise well-manicured lawn. The growth pattern of crabgrass tends to be more upright and less upright than desirable grasses, giving it a weedy appearance.

b. Visual Cues to Recognize Crabgrass

Clumping and Matting Effect: Crabgrass tends to clump together, creating dense patches with tangled stems. These clumps often intertwine, forming a mat-like structure that smothers the surrounding grass. This clumping effect is a telltale sign of crabgrass invasion.

Seed Heads and Inflorescence: As crabgrass matures, it produces seed heads that stand out from the rest of the lawn. These seed heads are typically upright and can range in color from light green to reddish-brown, depending on the species. The seed heads may resemble tiny spikes or branches with multiple seed clusters.

Common Locations for Crabgrass Infestations

Crabgrass is a resilient weed that can establish itself in various environments but has a particular affinity for certain locations. Understanding where crabgrass tends to thrive will help you anticipate its growth and take proactive measures to prevent its infestation. In this section, we will explore the preferred growing conditions for crabgrass and the typical areas where it is commonly found.

A. Preferred Growing Conditions

Soil and Temperature Requirements: Crabgrass favors compacted soil with poor drainage. It can tolerate a wide range of soil types but tends to thrive in areas where the soil is nutrient-deficient or has low organic matter content. Additionally, crabgrass prefers warmer temperatures and can be more prevalent in regions with hot summers.

Sunlight and Moisture Preferences: Crabgrass is a sun-loving weed that flourishes in areas exposed to full sunlight. It can withstand high heat and dry conditions better than many desirable grasses. Therefore, it often becomes more prominent in areas with inadequate irrigation or waterlogged spots.

B. Typical Areas Where Crabgrass Thrives

Lawns and Turf Areas: Crabgrass commonly infiltrates lawns and turf areas, especially those that are poorly maintained or subjected to heavy foot traffic. Thin or weak grass coverage provides an opportunity for crabgrass to take root and spread, eventually dominating the turf.
Garden Beds and Cracks in Pavements: Crabgrass is opportunistic and can establish itself in garden beds, flower borders, and even pavement cracks. These areas often offer favorable conditions, such as exposed soil, sunlight, and minimal competition from other plants.

What Does Crabgrass Look Like in Spring?

Spring is a crucial time to be vigilant in identifying and managing crabgrass as it begins its growth cycle. During this season, crabgrass exhibits specific characteristics that make it distinguishable from other grasses. This section will explore how crabgrass appears in spring, helping you recognize its presence and take timely action.

Germination and Early Growth: In the early stages of spring, when soil temperatures reach around 55 to 60 degrees Fahrenheit (12 to 15 degrees Celsius), crabgrass seeds start to germinate. Initially, you may notice small, pale green seedlings emerging from the soil.
Cotyledon Leaves: As the seedlings develop, they produce their first set of leaves known as cotyledons. Crabgrass cotyledons are wider and shorter compared to the true leaves that will follow. They often have a rounded or heart-shaped appearance.

Grass-Like Blades: As the crabgrass plants mature, they develop grass-like blades. These blades are wider, coarser, and often lighter in color than desirable grasses. They may exhibit a distinct V-shaped structure with pointed tips.
Upright Growth Habit: In the spring, crabgrass tends to grow more upright compared to desirable grasses. Its growth habit may appear more vigorous, with stems reaching upwards rather than spreading across the ground like a well-maintained lawn.
Clumping and Sparse Turf: Crabgrass in the spring tends to form clumps or patches, resulting in a sparse and uneven turf. These patches can become more prominent as the plants grow and mature. The overall effect can be a disheveled and unkempt appearance in an otherwise healthy lawn.

Note: It’s important to note that the appearance of crabgrass can vary depending on the specific species and local growing conditions. The descriptions provided here are general characteristics commonly observed in crabgrass during the spring season.

What Does Crabgrass Look Like in Winter?

During the winter months, crabgrass goes through a dormant period, and its appearance undergoes notable changes. While crabgrass is not actively growing during this time, it still retains some distinguishing characteristics that can help you identify it, even in its dormant state. In this section, we will explore how crabgrass looks in winter, enabling you to spot its presence and plan for effective control.

Browning and Discoloration: As temperatures drop and winter sets in, crabgrass undergoes browning and discoloration. The once vibrant green leaves turn brown, giving the weed a withered appearance. This is particularly noticeable in comparison to the surrounding desirable grasses, which may retain some green color or go dormant but not exhibit the same browning effect.

Mat-like Formation: Despite being dormant, crabgrass tends to maintain its clumping and mat-like growth habit throughout the winter. The previously developed patches or clumps of crabgrass remain intact, albeit in a dormant and browned state. These patches can stand out against the relatively uniform appearance of dormant turfgrass.
Persistent Seed Heads: Another feature to look for during winter is the presence of persistent seed heads on the crabgrass plants. These seed heads, which may have developed during the previous growing season, often remain attached to the weed throughout the winter months. They can be seen as small, brownish structures that protrude from the dormant crabgrass plants.
Low-Growing and Prostrate Form: In winter, crabgrass typically maintains a low-growing and prostrate form. The plants stay close to the ground and do not exhibit significant vertical growth. This can contribute to the clumping and mat-like appearance mentioned earlier.

Note: The appearance of crabgrass in winter can vary depending on local climatic conditions and the specific species present. The descriptions provided here are general characteristics commonly observed in crabgrass during the winter season.

What Does Dead Crabgrass Look Like?

After implementing control measures or as a result of changing seasons, crabgrass may die off, leaving behind its remains. Recognizing dead crabgrass is essential for assessing the success of your control efforts and determining the next steps in lawn maintenance. In this section, we will explore the characteristics of dead crabgrass, enabling you to identify its presence and take appropriate actions.

Brown and Withered Appearance: Dead crabgrass typically exhibits a brown and withered appearance. The once green and vibrant foliage turns dry and brittle, losing its vitality. This discoloration is a clear indication that the crabgrass has died.

Stunted Growth and Lack of Regrowth: Unlike desirable grasses that have the potential to recover and regrow, dead crabgrass remains stunted and shows no signs of new growth. The weed does not respond to favorable growing conditions, such as increased sunlight or irrigation, further confirming its demise.
Matted or Clumped Residue: Dead crabgrass often leaves behind a matted or clumped residue on the lawn surface. The previously sprawling and intertwined stems become flattened or compressed, forming a mat-like layer. This residue can hinder the growth of desirable grasses and create an uneven appearance in the lawn.
Lack of Seed Heads: Dead crabgrass no longer produces seed heads. The presence of seed heads is a notable feature of live crabgrass plants, but once the weed dies, these structures no longer develop or remain on the plant.

Ease of Removal: Dead crabgrass is easier to remove compared to live, healthy plants. The dry and brittle nature of the weed allows for easier uprooting or removal when performing lawn maintenance tasks, such as raking or dethatching.

By being able to identify the characteristics of dead crabgrass, such as its brown and withered appearance, lack of regrowth, matted residue, absence of seed heads, and ease of removal, you can assess the effectiveness of your control methods and determine the next steps in maintaining a healthy lawn.

Note: It’s important to differentiate between dead crabgrass and dormant crabgrass during winter. Dormant crabgrass retains its plant structure and may exhibit a brown color but can recover and regrow once favorable conditions return. Dead crabgrass, on the other hand, remains lifeless and shows no signs of recovery.

The Impact of Crabgrass on Lawns

Crabgrass, with its invasive nature, can significantly impact the health and appearance of lawns. Understanding the detrimental effects of crabgrass infestation is crucial for implementing effective control strategies and maintaining a thriving turf. In this section, we will explore the various ways in which crabgrass can impact lawns.

Competition for Resources: Crabgrass competes with desirable grasses for essential resources such as water, nutrients, and sunlight. Its aggressive growth can outcompete and overshadow the surrounding turf, leading to stunted growth and thinning of the desirable grass species.
Weakens the Turf: As crabgrass establishes itself and spreads, it weakens the overall structure of the lawn. The mat-like formation created by crabgrass patches hinders desirable grasses’ healthy growth and development, resulting in a compromised and uneven turf.

Aesthetically Unappealing: The presence of crabgrass can detract from the overall beauty and aesthetics of a lawn. Its coarse texture, clumping growth habit, and different coloration compared to desirable grasses create an unsightly and unkempt appearance.
Seed Production and Spread: Crabgrass is a prolific seed producer, generating a significant number of seeds during its growth cycle. These seeds can remain viable in the soil for multiple years, leading to future infestations if not properly managed. Additionally, the seeds can be easily dispersed by wind, water, animals, or human activities, facilitating the spread of crabgrass to other areas of the lawn or neighboring properties.
Difficult to Eradicate: Due to its resilient nature and ability to produce abundant seeds, crabgrass can be challenging to eradicate once it becomes established. It requires persistent and targeted control efforts to effectively manage its growth and prevent reinfestation.

Interference with Lawn Care Practices: The presence of crabgrass can interfere with regular lawn care practices, such as mowing, fertilizing, and overseeding. The uneven growth patterns and clumps of crabgrass can make mowing difficult and result in an uneven lawn surface. Additionally, fertilizers and overseeding efforts may not reach the desirable grasses effectively due to the dominance of crabgrass.

Preventing and Controlling Crabgrass

Prevention and control are key in managing crabgrass and maintaining a healthy lawn. By implementing preventive measures and employing effective control strategies, you can significantly reduce the presence and impact of crabgrass. In this section, we will explore several methods for preventing and controlling crabgrass infestations.

If you want to control crabgrass you have to know some points about crabgrass-

Crabgrass stems or leaves don’t grow like standing on the ground like other grasses. They have procumbent growth habit. Because of their low growing habit, they escape mower.
Crabgrass is an annual weed. It completes its life cycle within a year.
Crabgrass is drought tolerant and can survive the hottest days of the summer.

Crabgrass is not frost tolerant. The plan dies in frosts.
Crabgrass is identified as a C4 plant, what makes crabgrass tolerant to extreme weather conditions when all other grasses are dead or absent.
It does love hot humid weather condition.

Crabgrass only reproduces through seeds. A single plant can produce more than 500 tillers. At the end of its life in a year, its final task is to produce thousands of seeds. One crabgrass plant can produce more than 100 thousand seeds.
Seeds can germinate from the next year. Seeds can remain viable for several years.
A soil temperature of more than 54°F is required for crabgrass seeds to germinate.

You may have controlled crabgrass in the previous year and think that you are safe from crabgrass now. And you will be surprised by identifying even more crabgrass in your garden. This is because they were successful in spreading their seeds before their death. So the only way to get rid of crabgrass is to destroy crabgrass before seed set.

A. Preventive Measures

Proper Lawn Care Practices: Implement good lawn care practices to promote a healthy and dense turf, which helps prevent crabgrass from taking hold. This includes regular mowing, appropriate fertilization, adequate irrigation, and proper soil maintenance.
Early Spring Pre-Emergent Herbicide: Apply a pre-emergent herbicide specifically designed for crabgrass in early spring before the weed seeds germinate. This creates a barrier that inhibits crabgrass seedlings from emerging and establishing in the lawn.

Improve Soil Conditions: Maintain well-drained soil and improve soil fertility by adding organic matter, such as compost, to enhance the vigor and competitiveness of desirable grasses. This creates an environment less favorable for crabgrass growth.

B. Control Strategies

Post-Emergent Herbicides: If crabgrass has already emerged, consider using post-emergent herbicides that specifically target crabgrass. These herbicides should be applied when the weed is actively growing for optimal effectiveness.
Manual Removal: For small infestations, manually removing crabgrass by hand or using a tool like a weeding tool can be effective. Ensure to remove the entire plant, including the roots, to prevent regrowth.

Overseeding: Overseeding the lawn with desirable grass species helps fill in bare spots and compete with crabgrass. A dense and healthy lawn is more resistant to crabgrass invasion.
Regular Maintenance: Consistent lawn maintenance practices, such as proper mowing height, regular watering, and timely fertilization, contribute to a healthy lawn that can better resist crabgrass infestation.
Reduce Soil Disturbance: Minimize soil disturbance through activities like excessive foot traffic or construction projects, as this can create opportunities for crabgrass seeds to germinate and establish.

Hand Watering: Avoid overhead watering techniques that can encourage crabgrass growth. Instead, utilize hand watering or targeted irrigation methods to avoid wetting the entire lawn surface.

Note: Remember to read and follow all product labels and safety instructions when using herbicides or other chemicals. It’s also important to consider the specific conditions and requirements of your region and grass type when implementing control strategies.

When to use a crabgrass preventer?

You may believe that very early springtime is the ideal time to jump onto making use of crabgrass preventer. But, maybe crabgrass maintains a thermostat instead of a schedule.
Pre-emergents are indicated to stop the crabgrass prior to it comes out of the soil. Applying pre-emergent early will not control crabgrass. Using postemergence herbicides to weeds popped up over your grass will certainly take treatment of the crabgrass. Make certain that the yard has the nutrients it requires to deal with the weeds and crabgrass. A solid expanding grass leaves little space for crabgrass invasions.
Apply fertilizer with pre-emergent to conserve your time for your lawn care. It is possible to integrate 2 therapies ( postemergence herbicides and preemergence herbicides).
Using postemergence herbicides to crabgrass that stand out in your yard will certainly take care of the crabgrass. Inspect your lawn for brand-new weeds during trimming to ensure you capture the actively expanding weeds early.

So, how to control crabgrass in your garden or lawn?

Now you know that the only way to get rid of crabgrass from your garden or lawn is to destroy them before their seed set. And if you have destroyed crabgrass last year after seed production then you have to stop seed germination.

Look at your lawn or garden carefully. If your lawn or garden has a small infestation with crabgrass, remove them manually with a knife. But be sure not to spread the seeds in your garden. You should remove crabgrass before setting seeds.
If you identify crabgrass without seed kill them with a manual weeder or by the herbicide. But please try to avoid chemical herbicide until you have no other way to control weeds. Before applying herbicide please look for the instructions written on the packet carefully. These herbicides may kill other grass seeds too. So, do not use lawn grass seeds within 2 to 3 months of herbicide application.

If you miss controlling crabgrass seed germination, use a good post-emergence herbicide in the 2-5 leaves stage following the instructions carefully.
If you had crabgrass with seeds in the previous year/years then you have to stop the seed germination by using a good pre-emergent herbicide. But that herbicide may kill your desired grass in your lawn or other plants in your garden. So read the instructions written on the packet before applying.
Grazing by cattle or goats before the seed set can be a good way to control crabgrass.

Repeated control of seed production in several years may help you to get rid of crabgrass.
Crabgrass is very hardy. So it can survive in low nutrition but other desired grass in lawn can’t. As a result, your lawn is attacked by crabgrass. So, apply fertilizer for your lawn grass so that they can win against crabgrass.
Crabgrass gets benefits from fertilizer in high-temperature conditions. So, if you have crabgrass in your garden in summer, do not apply fertilizer without removing them.

Frequent light irrigation is good for crabgrass growth. So, to control crabgrass avoid this.
Crabgrass seeds cannot germinate in low soil temperatures. So, keep your desired lawn grasses at least 2-3 inches tall to keep soil temperature under control.
A thick, as well as healthy lawn, will certainly block crabgrass and other weeds from expanding.

Crabgrass likes to expand in bare areas in your lawn. Seeding as well as overseeding will certainly fill up in the bare places and also thicken the vegetation layer of your grass making it harder for crabgrass to penetrate the soil.
Make certain that the desired grasses or plants have nutrients to combat crabgrass. Ensure your lawn is with normal fertilizing. Your lawn or garden will be easily attacked by unwanted weeds if your desired grasses or plants are lacking nutrients.
Soil aeration can aid with weed prevention as well as removes compaction of the soil. When soil is compressed, the lawn roots do not get adequate air as well as water. This can be a cause of a weak lawn.

A strong expanding lawn leaves little space for crabgrass invasions. You cannot kill the crabgrass by drying your yard as it is drought tolerant, so be certain to maintain water for your grasses so they can block the crabgrass and various other weeds.

Is crabgrass always bad?

Let’s look for something good about crabgrass.
Crabgrass is good forage for livestock including cattle and goats. It is easy to cultivate and nutritious for them.
Crabgrass can check soil erosion. Crabgrass can grow in low fertile soil and can survive in drought conditions. Because of its quick-growing nature and survival capacity in stress, crabgrass can be a good option to cover barren soil.

Conclusion

Crabgrass can be a persistent and invasive weed that poses challenges to maintaining a healthy and aesthetically pleasing lawn. However, with proper knowledge and proactive measures, you can prevent its establishment and effectively control its growth. By understanding the characteristics of crabgrass, identifying its presence in different seasons, and recognizing the detrimental impact it can have on lawns, you are equipped to take the necessary steps to combat this weed.

Prevention is always the best approach, and implementing preventive measures such as proper lawn care practices, early spring pre-emergent herbicide applications, and improving soil conditions can greatly reduce the likelihood of crabgrass infestations. Additionally, employing control strategies such as post-emergent herbicides, manual removal, overseeding, regular maintenance, and reducing soil disturbance can help manage existing crabgrass populations.

Remember that consistent vigilance, timely action, and adherence to recommended practices are essential in successfully preventing and controlling crabgrass. Regular monitoring of your lawn, implementing appropriate control methods, and maintaining a healthy turf will ensure that crabgrass remains at bay, allowing your desirable grasses to thrive.

By taking the necessary steps to prevent and control crabgrass, you can achieve a beautiful, lush, and weed-free lawn that enhances the overall aesthetics of your outdoor space. Enjoy the satisfaction of a well-maintained lawn and the benefits it brings to your property.