Crabgrass, the bane of many homeowners’ existence, is a particularly aggressive and unsightly weed that can quickly take over a lawn. Its sprawling growth habit and resilience make it a formidable opponent. This is why professional landscapers employ a range of strategies and products to effectively control and eliminate crabgrass infestations. Understanding these methods can help you manage your own lawn or make informed decisions when hiring a professional.
Understanding Crabgrass: The Enemy Defined
Before diving into the arsenal of crabgrass-killing tools, it’s crucial to understand the weed itself. Crabgrass is a warm-season annual, meaning it germinates in the spring, thrives in the summer heat, produces seeds, and then dies off in the fall. Identifying it early is key to successful control.
Crabgrass is easily recognizable by its coarse texture and light green color, which contrasts with the darker green of desirable turf grasses. Its growth pattern is also distinctive, radiating outwards from a central point, resembling a crab. There are several species of crabgrass, with smooth crabgrass (Digitaria ischaemum) and hairy crabgrass (Digitaria sanguinalis) being the most common.
Understanding the crabgrass lifecycle is critical for effective control. Knowing when it germinates, grows, and produces seeds allows for targeted application of pre-emergent and post-emergent herbicides.
Pre-Emergent Herbicides: Preventing Crabgrass Before It Starts
Pre-emergent herbicides are a cornerstone of crabgrass control for landscapers. These products are applied to the lawn before crabgrass seeds germinate, typically in early spring before soil temperatures reach a consistent 55 degrees Fahrenheit. They work by creating a chemical barrier in the top layer of soil, preventing the newly germinated crabgrass seedlings from developing properly.
Timing is everything with pre-emergent herbicides. Applying them too early or too late will significantly reduce their effectiveness. Landscapers often use soil thermometers to accurately gauge soil temperature and ensure optimal application timing.
Common Pre-Emergent Herbicides Used by Landscapers
Several pre-emergent herbicides are commonly used by landscapers, each with its own advantages and disadvantages.
- Dithiopyr: Dithiopyr is a popular choice due to its relatively long residual control and its ability to control crabgrass both pre- and early post-emergence. This offers a wider window of opportunity for application.
- Prodiamine: Prodiamine is another widely used pre-emergent herbicide known for its long-lasting control. It is particularly effective on established lawns and provides excellent prevention against a variety of annual weeds.
- Pendimethalin: Pendimethalin is a cost-effective pre-emergent herbicide that provides good control of crabgrass and other annual weeds. It is often used in combination with other herbicides for broader spectrum weed control.
- Benefin: Benefin is an older pre-emergent herbicide, still used for its effectiveness in certain situations. It is often used in combination with trifluralin for broadleaf weed control.
Landscapers carefully consider factors such as soil type, lawn type, and the history of weed infestations when selecting the appropriate pre-emergent herbicide. They also ensure proper application rates and techniques to maximize effectiveness and minimize potential harm to desirable turf grasses.
Application Techniques for Pre-Emergent Herbicides
Proper application is crucial for the success of pre-emergent herbicides. Landscapers use specialized equipment to ensure even and accurate application.
Granular pre-emergent herbicides are typically applied using a broadcast spreader, which distributes the granules evenly over the lawn surface. Liquid pre-emergent herbicides are applied using a sprayer, ensuring thorough coverage of the soil.
Watering in pre-emergent herbicides is essential to activate the chemical barrier and move the herbicide into the soil where crabgrass seeds germinate. Landscapers typically recommend irrigating the lawn shortly after application.
Post-Emergent Herbicides: Eliminating Existing Crabgrass
Even with the best pre-emergent strategies, crabgrass can sometimes still emerge. In these cases, post-emergent herbicides are necessary to kill existing crabgrass plants. These herbicides are applied directly to the crabgrass leaves, where they are absorbed and transported throughout the plant, ultimately killing it.
Post-emergent herbicides are most effective when applied to young, actively growing crabgrass plants. Landscapers carefully monitor lawns for early signs of crabgrass emergence and apply post-emergent herbicides as soon as possible.
Common Post-Emergent Herbicides Used by Landscapers
Several post-emergent herbicides are available, each with its own mode of action and effectiveness against different crabgrass species.
- Quinclorac: Quinclorac is a widely used post-emergent herbicide that is effective against both young and mature crabgrass plants. It works by disrupting cell wall growth, leading to plant death.
- Acclaim Extra (Fenoxaprop-p-ethyl): Acclaim Extra is a selective post-emergent herbicide that is particularly effective against crabgrass. It works by inhibiting an enzyme essential for fatty acid synthesis, disrupting plant growth.
- MSMA (Monosodium Methanearsonate): MSMA is an older post-emergent herbicide that is still used in some situations. However, its use is restricted in some areas due to environmental concerns. It is most effective on young crabgrass plants.
- Selective Herbicides: There are different herbicides tailored for various grass types. For example, some products are safe to use on Bermuda grass while effectively targeting crabgrass.
Landscapers carefully select the appropriate post-emergent herbicide based on the type of crabgrass present, the type of turf grass, and environmental considerations.
Application Techniques for Post-Emergent Herbicides
Post-emergent herbicides are typically applied using a sprayer, ensuring thorough coverage of the crabgrass leaves. Landscapers often use spot treatments, targeting individual crabgrass plants to minimize the impact on desirable turf grasses.
Proper application techniques are essential to maximize the effectiveness of post-emergent herbicides and minimize the risk of injury to desirable plants. Landscapers carefully follow label instructions and use appropriate personal protective equipment.
Cultural Practices: A Holistic Approach to Crabgrass Control
While herbicides are an important tool in crabgrass control, landscapers also emphasize the importance of cultural practices. These practices promote healthy turf growth, making it more difficult for crabgrass to establish.
A dense, healthy lawn is the best defense against crabgrass.
Key Cultural Practices for Crabgrass Prevention
- Proper Mowing Height: Mowing the lawn at the correct height (typically 2.5 to 3 inches) helps to shade the soil, preventing crabgrass seeds from germinating.
- Regular Fertilization: Fertilizing the lawn regularly provides the nutrients needed for healthy turf growth, allowing it to outcompete crabgrass.
- Proper Irrigation: Watering deeply and infrequently encourages deep root growth, making the lawn more drought-tolerant and less susceptible to crabgrass infestation.
- Aeration: Aerating the lawn helps to improve soil drainage and aeration, promoting healthy root growth.
- Overseeding: Overseeding thin or bare areas of the lawn helps to create a denser turf, making it more difficult for crabgrass to establish.
- Soil Testing: Testing the soil pH and nutrient levels and amending as needed will ensure optimal growing conditions for your desired turf.
Landscapers work with homeowners to develop a comprehensive lawn care plan that incorporates both chemical and cultural practices for effective crabgrass control.
Professional Equipment and Expertise
Landscapers possess the specialized equipment and expertise necessary to effectively control crabgrass. They have access to commercial-grade herbicides that are not available to homeowners. They also have the knowledge and experience to properly diagnose crabgrass infestations, select the appropriate herbicides, and apply them safely and effectively.
Investing in professional lawn care can save you time, money, and frustration in the long run.
Landscapers can also provide valuable advice on cultural practices that can help to prevent future crabgrass infestations. Their expertise ensures that your lawn remains healthy and weed-free.
Considerations When Choosing a Crabgrass Control Strategy
Selecting the right crabgrass control strategy involves several key considerations. These factors include the type of grass you have, the extent of the crabgrass infestation, environmental concerns, and personal preferences. A landscaper will assess these aspects to create a tailored solution.
Understanding your lawn and the specific crabgrass challenges is crucial.
Key Considerations for Effective Crabgrass Control
- Grass Type: Different types of grass have different tolerances to herbicides. Landscapers choose herbicides that are safe for your specific grass type.
- Infestation Level: The severity of the crabgrass infestation will determine the type and amount of herbicide needed.
- Environmental Concerns: Landscapers are aware of the environmental impact of herbicides and take steps to minimize their use. They may recommend alternative control methods, such as hand-pulling or organic herbicides.
- Personal Preferences: Some homeowners prefer to avoid using herbicides altogether. Landscapers can work with them to develop a cultural-based crabgrass control plan.
- Timing: The time of year and the crabgrass lifecycle stages greatly influence the success of different treatment methods.
- Budget: Crabgrass control can range from DIY methods to professional applications. Setting a budget helps determine the best approach.
By carefully considering these factors, landscapers can develop a crabgrass control strategy that is effective, safe, and environmentally responsible.
In conclusion, landscapers utilize a multi-faceted approach to crabgrass control, combining pre-emergent and post-emergent herbicides with sound cultural practices. Their expertise, access to professional-grade products, and specialized equipment make them well-equipped to tackle even the most severe crabgrass infestations, ensuring a healthy, beautiful lawn for their clients. While DIY options exist, professional help often proves to be the most effective and efficient long-term solution.
Choosing the right strategy involves a careful assessment of your lawn’s specific needs and conditions. By working with a qualified landscaper, you can achieve optimal crabgrass control and maintain a lush, weed-free lawn for years to come. Remember that consistent and preventative care are essential to ward off future infestations.
What are the most common herbicides landscapers use to kill crabgrass?
Landscapers often rely on two primary types of herbicides: pre-emergent and post-emergent. Pre-emergent herbicides are applied before crabgrass seeds germinate, creating a barrier in the soil that prevents the seedlings from emerging. These are typically applied in early spring, before soil temperatures reach the point where crabgrass starts to grow. Common active ingredients in pre-emergent herbicides include dithiopyr, prodiamine, and pendimethalin.
Post-emergent herbicides, on the other hand, are used to target crabgrass that has already sprouted. These herbicides are effective in killing established crabgrass plants. Common active ingredients used in post-emergent herbicides for crabgrass control include quinclorac, mesotrione (sometimes used for broadleaf weed control but also effective on young crabgrass), and sulfentrazone. The choice between pre-emergent and post-emergent herbicides depends on the stage of crabgrass growth and the landscaper’s overall strategy for weed control.
When is the best time for landscapers to apply crabgrass killer?
The optimal timing for applying crabgrass killer is dependent on whether you’re using a pre-emergent or a post-emergent herbicide. Pre-emergent herbicides should be applied in early spring, before the soil temperature reaches 55 degrees Fahrenheit for several consecutive days. This typically corresponds to the time when forsythia bushes are in bloom. Applying too late will render the pre-emergent ineffective, as the crabgrass seeds will already have germinated.
Post-emergent herbicides are best applied when the crabgrass is young and actively growing. This is typically during the late spring or early summer. For optimal results, apply post-emergent herbicides on a calm day, avoiding windy conditions that could cause drift and harm desirable plants. Follow the manufacturer’s instructions carefully regarding application rates and precautions to ensure effective crabgrass control.
Are there organic or natural options for landscapers to control crabgrass?
Yes, landscapers can utilize organic and natural methods for crabgrass control, although they may require more frequent application and may not be as immediately effective as synthetic herbicides. Corn gluten meal is a popular pre-emergent organic option. It contains proteins that inhibit root formation in newly germinated seeds, preventing crabgrass from establishing itself. However, it needs to be applied at the correct time and in sufficient quantities to be effective.
Another organic method involves manually removing crabgrass, either by hand-pulling or using a weeding tool. This is most effective for small infestations. Furthermore, improving lawn health through proper fertilization, watering, and mowing practices can help create a dense turf that naturally outcompetes crabgrass. Overseeding bare spots with desirable grass seed also helps to reduce the available space for crabgrass to germinate.
How do landscapers prevent crabgrass from returning year after year?
Landscapers employ a multi-faceted approach to prevent the recurring growth of crabgrass. This typically involves a combination of pre-emergent herbicide applications in the spring and post-emergent herbicide applications when necessary. Consistent monitoring of the lawn is essential to identify and address any new outbreaks promptly. Furthermore, maintaining a healthy and dense lawn is the best defense against crabgrass.
In addition to chemical controls, landscapers focus on promoting vigorous turf growth through proper fertilization, watering, and mowing practices. Regular aeration and dethatching can improve soil health and encourage deeper root growth, making the lawn more resilient to weed infestations. Finally, ensuring proper drainage and correcting any soil compaction issues can also contribute to a healthier lawn environment that is less susceptible to crabgrass.
What safety precautions should landscapers take when using crabgrass killers?
Safety is paramount when applying crabgrass killers, and landscapers must adhere to strict precautions. Always read and follow the manufacturer’s instructions on the product label carefully. Wear appropriate personal protective equipment (PPE), including gloves, eye protection, long sleeves, and long pants, to minimize skin and eye contact with the herbicide.
Avoid applying herbicides on windy days to prevent drift, which could harm desirable plants or contaminate nearby water sources. Keep children and pets away from treated areas until the herbicide has dried completely. Properly store herbicides in a secure location, out of reach of children and animals. Dispose of empty containers according to local regulations.
How do landscapers identify crabgrass to ensure proper treatment?
Landscapers rely on several visual cues to accurately identify crabgrass. Crabgrass typically has a coarse, light-green appearance and grows in a sprawling, bunch-like manner, often forming a mat-like appearance. Its blades are wider than those of most common lawn grasses, and it tends to grow prostrate, or horizontally, along the ground. The seed heads of crabgrass are distinctive, featuring multiple finger-like spikes that radiate from a central point.
Another key identifying factor is the timing of its growth. Crabgrass is a summer annual, meaning it germinates in the spring, grows throughout the summer, and dies off in the fall with the first frost. Unlike perennial grasses, crabgrass will not persist through the winter. By observing these characteristics and understanding the growth cycle of crabgrass, landscapers can accurately identify it and implement appropriate control measures.
Can landscapers use selective herbicides to kill crabgrass without harming the lawn?
Yes, landscapers frequently use selective herbicides designed to target crabgrass without harming the desired lawn grasses. These herbicides work by targeting specific metabolic pathways or physiological processes that are present in crabgrass but not in common turf grasses like Kentucky bluegrass, perennial ryegrass, and fescues. This allows for effective crabgrass control while preserving the overall health of the lawn.
However, it’s crucial to choose the right selective herbicide and apply it according to the manufacturer’s instructions. Some selective herbicides may still cause temporary discoloration or stress to the lawn grasses, particularly during hot or dry weather. Landscapers often test the herbicide on a small, inconspicuous area of the lawn before applying it to the entire area to ensure compatibility and minimize any potential damage.