If you have patches of grass in your lawn that look different from the surrounding turf, grow faster, have a different color or texture, or seem to spread over time, you may be dealing with an invasive grass.
Common invasive grasses in Minnesota and Wisconsin lawns include:
• Tall fescue
• Creeping bentgrass
• Rough bluegrass
• Reed canarygrass
• Quackgrass
These grasses are extremely common in home lawns and often spread aggressively once established.
What Makes a Grass “Invasive” in a Lawn?
Invasive grasses are grasses growing where they are not wanted.
Most home lawns in Minnesota and Wisconsin are made up of Kentucky bluegrass, perennial ryegrass, and fine fescue. Invasive grasses stand out because they have different growth habits, colors, textures, or spreading characteristics.
Some invasive grasses:
• Grow much faster than the surrounding lawn
• Stay lime green while the lawn is darker green
• Form patches or clumps
• Spread aggressively through runners or rhizomes
• Become puffy or uneven after mowing
• Thrive in wet or stressed areas
• Create a patchy or inconsistent appearance
Many homeowners mistake these grasses for crabgrass, especially in the spring. However, crabgrass is a summer annual weed and usually does not become visible until later in the season. If you are seeing patches of odd looking grass in April or May, it is often an invasive perennial grass instead.
Why These Grasses Show Up
Invasive grasses are extremely common and can enter lawns many different ways.
They may come from:
• Sod or seed mixes
• Nearby native areas or wetlands
• Construction disturbance
• Birds and wildlife
• Equipment movement
• Existing soil seed banks
Some grasses, like rough bluegrass and creeping bentgrass, are commonly found in shady or wet areas. Others, like tall fescue or reed canarygrass, tolerate drought, poor soils, or compacted conditions better than desirable turfgrass.
In many cases, homeowners did nothing wrong. These grasses are simply very aggressive and capable of spreading into lawns over time.
Now That You Have Invasive Grass, What Can You Do as a Homeowner?
There are generally three options when dealing with invasive grasses in a lawn.
1. Live With It
This is the most common option. Many lawns contain some invasive grasses and still function perfectly well. While the patches may stand out visually, they are usually cosmetic and do not harm the lawn overall.
For many homeowners, the most practical approach is simply managing the lawn normally and accepting some variation in texture or color.
2. Dig Out the Affected Area
If the patch is small, homeowners can physically remove the invasive grass.
This typically involves:
• Digging out the affected area several inches deep
• Removing as much of the root system and runners as possible
• Disposing of the removed material
• Adding new soil if necessary
• Reseeding or resodding the area afterward
3. Use a Total Vegetation Control Product
Invasive grasses cannot be selectively removed from cool season lawns with weed controls without damaging desirable grass nearby. Because of this, homeowners sometimes choose to use a non selective herbicide that kills all vegetation in the affected area.
After the grass has died:
• Remove dead material if needed
• Prepare the soil surface
• Reseed or resod the area
This is often the most effective option for large aggressive invasive grasses, especially when patches continue spreading.
What Can bioLawn Do?
Unfortunately, there are not selective control options for invasive grasses in cool season lawns. So our weed control treatments will not control invasive grasses. Once invasive grass is established, bioLawn can:
- Advise you on removal and treatment options
- Fertilize the lawn to blend the color of the grass
- Seed the lawn to introduce desirable grasses that will compete with the invsaive grass
In the Future, What Can Homeowners Do to Prevent Invasive Grasses?
Prevention focuses on creating a dense, healthy lawn. Healthy turf naturally competes against invasive grasses better than thin or stressed lawns.
Helpful practices include:
• Mowing high
• Watering deeply and infrequently
• Avoiding overwatering
• Overseeding thin areas
• Improving drainage
• Reducing soil compaction
The Reality of Invasive Grasses
One of the most frustrating parts of invasive grasses is that there is rarely a quick or perfect solution.
Many homeowners expect a simple spray application that removes the unwanted grass without affecting the lawn. Unfortunately, cool season lawns do not have many selective control options for grassy weeds.
In many situations, management and improvement are more realistic goals than complete eradication.
The good news is that invasive grasses are usually cosmetic rather than harmful. While they may affect the appearance and uniformity of the lawn, they rarely destroy the lawn entirely.
With proper expectations and a long term management approach, most lawns can still look very good even when some invasive grasses are present.