Quackgrass in Cool Season Lawns: Identification, Causes, and What to Do

Quackgrass is one of the most common and frustrating grassy weeds found in cool season lawns in Minnesota and Wisconsin. It often shows up unexpectedly, spreads quickly, and can be difficult to remove once established.

How to Identify Quackgrass

Quackgrass is a perennial grassy weed that is commonly found in lawns, roadsides, fields, and natural areas. In fact, it is often planted on roadsides in Minnesota and Wisconsin due to its extensive rooting nature and resilience.  It often makes its way into lawns through seed, sod, or surrounding native areas, which is why it is so common to see

Key quackgrass characteristics include:

• Lighter green color compared to surrounding turf
• Wider leaf blades than typical lawn grasses
• Rapid growth compared to the rest of the lawn
• Clasping auricles at the base of the leaf
• Strong underground rhizomes that spread aggressively

Quackgrass is often scattered throughout the lawn rather than just along edges, which can make it more noticeable as it grows faster than the surrounding turf.

Quackgrass vs Crabgrass: A Common Spring Confusion

Every spring, we receive calls from homeowners concerned about crabgrass showing up early in the season. In almost every case, what they are seeing is actually quackgrass.

The easiest way to tell the difference is timing. Crabgrass is an annual weed that does not germinate until soil temperatures warm up, so it typically does not appear until June. If you are seeing grassy weeds in April or May, it is not crabgrass.

Other ways to tell the difference:

• Quackgrass has deeper, stronger roots and cannot be easily pulled
• Crabgrass pulls out easily from the soil
• Quackgrass grows more upright and blends into the lawn
• Crabgrass grows in a wider, spreading, clumpy pattern
• Quackgrass is often found throughout the lawn
• Crabgrass is more commonly found along edges like driveways and sidewalks

Why Does Quackgrass Show Up in Lawns

Quackgrass is not necessarily a sign of poor lawn care. In many cases, it is introduced unintentionally. Common ways it enters lawns:

• Present in native soil or surrounding areas. We see this often in new builds where the soil below the sodded lawn is contaminated.
• Introduced through seed mixes. Many inexpensive seed mixes include quackgrass.
• Brought in with sod during installation. Some sod fields are contaminated and quackgrass may be present in the soil without the sod grower knowing.
• Spread from nearby unmanaged areas. Native areas surrounding homes often contribute to a quackgrass problem.

Because it spreads through underground rhizomes, once it is in the lawn it can expand quickly and become persistent.

What You Can Do as a Homeowner Once Quackgrass is in Your Lawn

Once quackgrass is present, control is challenging and often requires a targeted approach. Your options include:

• Spot killing and reseeding – Apply a non selective herbicide to the affected area. This will kill both the quackgrass and the surrounding turf. After the area is fully dead, it can be reseeded or sodded.
• Digging out affected areas – For small patches, physically removing the soil can be effective. This requires removing several inches beyond the visible patch and digging 6-12 inches down to ensure all rhizomes are removed. Then fill with clean soil and reseeded or sodded.
• Living with it – Because of how difficult it is to fully eliminate, many homeowners choose to tolerate quackgrass, especially if it is scattered and not overly disruptive to the lawn’s appearance. In this case, following proper mowing and watering practices can reduce further spread.

It is important to note that pulling quackgrass is typically ineffective and can actually encourage more growth due to remaining rhizomes .

What bioLawn Do Once You Have Quackgrass in Your Lawn

At this time, there are no selective treatments that can remove quackgrass without also damaging desirable turfgrass. Because of this, our approach focuses on guidance rather than direct control. We can help by:

• Properly identifying quackgrass versus other grassy weeds
• Outlining realistic options
• Recommending the best strategy based on the level of infestation and your capabilities
• Maintain fertility levels to encourage dense strong grass growth
• Overseed the lawn to introduce competition to the quackgrass

Our goal is to help you make the most informed decision based on your lawn goals and tolerance for disruption.

What Can a Homeowner Do to Prevent Quackgrass

Prevention is difficult, but there are ways to reduce the likelihood of quackgrass becoming a problem. Best practices include:

• Using high quality seed when overseeding
• Being selective with sod sources
• Maintain lawn health through proper watering and mowing
• Monitoring early and addressing small patches quickly

Even with good practices, some level of quackgrass introduction is possible due to its presence in surrounding environments.

What bioLawn Can Do to Prevent Quackgrass

While we cannot fully prevent quackgrass, we can help build a lawn that is more competitive and resilient. Our approach includes:

• Strengthening turf density through proper fertilization
• Overseeding to introduce newer more competitive grass varieties

A thicker, healthier lawn will not eliminate quackgrass, but it can help slow its spread and reduce its visibility.

Final Thoughts

Quackgrass is a very common part of cool season lawns, especially in areas where it exists in surrounding landscapes or has been introduced through seed or sod. While it can be frustrating, it is not uncommon and does not mean your lawn is failing.

Managing quackgrass comes down to balancing expectations, effort, and desired lawn appearance. In many cases, the best approach is a combination of targeted removal and maintaining a strong, healthy lawn moving forward.

If you would like help identifying whether your lawn has quackgrass or want to discuss quackgrass management options, please reach out to our agronomist.