How Does Bentgrass Spread?

10 Dec How Does Bentgrass Spread?

Bentgrass is known for its exceptional density and fine appearance, qualities that make it one of the most popular turf species for golf greens, bowling greens, and ornamental lawns. But for many homeowners, bentgrass is less of an asset and more of an invasive guest.

Understanding how bentgrass spreads, why it appears, and how to control or remove it will help you protect your lawn and manage this vigorous cool-season grass effectively.

What Is Bentgrass?

Bentgrass belongs to the Agrostis genus and is classified as a perennial cool-season grass. The most common species used in turf applications is creeping bentgrass (Agrostis stolonifera), prized for its ability to create a dense, uniform surface. Some key traits of Bentgrass include:

• Fine, soft leaf blades with a light to medium green colour
• Thrives in cool, moist conditions
• Spreads aggressively through stolons (above-ground runners)
• Performs best under close mowing (5–10mm)

Bentgrass is ideal for golf courses and bowling greens, but is rarely recommended for general-purpose lawns due to its high maintenance requirements. However, bentgrass is also highly aggressive, spreading quickly and overtaking other turf varieties if unmanaged, particularly in home lawns where mowing heights are higher and maintenance routines are less strict.

Pros and Cons of Bentgrass

Bentgrass can be either a premium choice or a problematic invader, depending on your lawn’s purpose.

Pros

• Exceptional density and coverage: Bentgrass forms a tightly woven, velvety surface that creates a true “carpet-like” appearance.

• Responds strongly to fertilisation: Bentgrass has a high nutrient uptake and reacts quickly to balanced fertiliser programs, allowing it to grow quickly and fill in bare patches.

• Aesthetic appeal and fine leaf texture: The visually striking fine blades and bright-to-deep green colour give bentgrass a premium, manicured look.

• Performs well in cool climates: Bentgrass thrives where summers are mild and winters are cool. It stays active for a larger portion of the year than warm-season grasses, offering year-round colour and growth in many southern regions.

Cons

• Extremely invasive in mixed lawns: Bentgrass spreads rapidly through stolons and can easily infiltrate buffalo, kikuyu, couch, or fescue lawns. Once it starts taking over, it can quickly become the dominant species and crowd out the existing turf.

• Prone to thatch build-up: Its dense growth habit causes organic material to accumulate at the soil surface. Excessive thatch restricts water, air, and nutrient movement and can lead to shallow rooting and disease problems.

• Susceptible to fungal diseases: Humidity, overwatering, or poor airflow can trigger issues like dollar spot, brown patch, or snow mould.

• Poor heat and drought tolerance: Bentgrass struggles during hot summers or extended dry periods, causing it to thin out and be discoloured, requiring more water than most warm-season lawn varieties.

What Causes Bentgrass to Spread?

Even if you didn’t intentionally plant it, bentgrass can establish itself in your lawn due to several factors:

1. Stolons and Rhizomes

Stolons are stems that grow horizontally above the surface of the soil. These stolons send out new roots at their tips, which helps bentgrass spread.

Rhizomes are similar to stolons. These are stems that grow horizontally and below the soil’s surface, eventually growing new shoots and roots.

2. Seeds

Bentgrass produce seeds that germinate quickly (usually around 7-15 days), leading to a wider spread. Additionally, some low-cost seed blends contain traces of bentgrass, which can germinate unnoticed before spreading across the yard.

3. Overwatering or Shaded Environments

Bentgrass thrives in moist, shaded, cool areas. These conditions make many warm-season grasses decline, allowing bentgrass to fill the gaps.

How to Get Rid of Bentgrass

Controlling or removing bentgrass requires a deliberate strategy. Here are the most effective methods:

1. Use Pre-Emergent Herbicides

Use pre-emergent herbicides to target bentgrass before it spreads. Apply this during early spring or fall to prevent bentgrass seeds from germinating. In the case of creeping bentgrass, it is recommended to use herbicides with prodiamine or pendimethalin.

2. Use Post-Emergent Herbicides

Post-emergent herbicides target specific weeds and plants after they’ve emerged. Selective herbicides effective against bentgrass are limited, so lawn professionals recommend a non-selective herbicide spot treatment (glyphosate), followed by renovation and reseeding or re-turfing. This method is often the most reliable for moderate-to-large infestations.

3. Solarisation

Solarisation is the process of covering your plants or weeds with a clear plastic sheet and heating them until they die. This is an effective method to use against bentgrass, which has poor heat tolerance.

Cover the bentgrass for about a week for it to die completely. However, be careful not to cover any wanted plants under the plastic, as these will die as well due to the extreme heat. 

4. Manual Removal

Bentgrass’s shallow roots make removal possible, but stolons can hide deeper than expected. Dig out the affected area, including stolons and the root system. Remove surrounding soil where stolons may extend. Refill with clean soil and re-establish your desired turf species.

For more tips on how to take care of your turf, check out our guide on lawn care and maintenance!

Seek Expert Advice From Seed and Turf

Understanding how bentgrass spreads is essential, whether you want to cultivate it or eliminate it. Its aggressive growth habit makes it perfect for high-maintenance, fine-turf environments, but challenging for the average home lawn.

If you’re unsure whether bentgrass is the right choice, or you’re dealing with a spreading infestation, our turf specialists at Seed & Turf can help.

Talk to Seed & Turf today to find the best solution for your lawn, from growing a premium bentgrass surface to reclaiming your yard from unwanted spread.