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Key Takeaways

  • Many superintendents find themselves in a position where Poa annua is the dominant turf species on the putting greens they maintain.

  • An agronomic program must be tailored to maximize the strengths and minimize the weaknesses of Poa annua, with consideration given to the site-specific conditions of the course. 

  • High-quality putting conditions are possible when the necessary resources are provided, realistic expectations are set and the risk potential is understood. 

When it comes to cool-season putting greens, there is often a focus on promoting creeping bentgrass and suppressing Poa annua. Creeping bentgrass is better suited to withstand temperature extremes, dry conditions and disease pressure. These reasons along with the savings associated with applying fewer plant protects and not having to dedicate as much time to wilt watching are often the driving forces behind investments to establish creeping bentgrass on putting greens. So, why would some facilities willingly choose to have Poa annua putting greens instead of creeping bentgrass?

The simple answer is that creeping bentgrass does not outperform Poa annua in every category when it comes to comparing these grasses on putting greens. Poa annua is more tolerant of low-light environments and is more traffic tolerant than creeping bentgrass. Given certain circumstances, Poa annua can just make sense.

At some facilities with Poa annua putting greens, this turfgrass is simply the preference of golfers or those holding leadership positions. The pros and cons have been thoroughly evaluated and a decision was made favoring Poa annua as the desired putting surface. Provided that decision-makers have set realistic expectations, understand the risk potential and provide the necessary resources, high-quality putting conditions can certainly be delivered on Poa annua greens.

For many facilities, Poa annua is the dominant turf species present on the putting surfaces because this is how the putting greens have evolved over time. As a result, superintendents often have to make do with Poa annua because it is not an option to resurface or rebuild.

Regardless of why Poa annua is being maintained, an intricate understanding of the strengths and weaknesses of this grass is necessary for successful management. As is an in-depth understanding of the agronomics needed to optimize turf health and playing conditions.

"Regardless of why Poa annua is being maintained, an intricate understanding of the strengths and weaknesses of this grass is necessary for successful management."

Cultural Management

A sound cultural program must be developed to manage organic matter, balance air and water porosities, reduce compaction, and allow water to move into and through the soil profile. Collecting data in the form of soil tests and surface performance characteristics can provide valuable information on how cultural practices are affecting the putting greens. These recommendations apply to managing any type of putting green, but they are particularly important when it comes to Poa annua greens because this grass can quickly begin to underperform or fail without careful management.

Samples should be collected from putting greens every year to track organic matter levels. A common approach is to sample one of the best-performing greens, an average green and a challenging green. These samples should then be sent to the same lab at approximately the same time of year so comparisons can be made from year to year.

In addition to the previously mentioned data collection, overall turf health should be monitored to determine if the current cultural management program is working or whether the program needs adjustment to reduce or increase organic matter levels. Remember that some organic matter is necessary to aid turf resiliency. When too little organic matter is present, the playing surface can become weak and greens will be more receptive.

Organic matter is managed through dilution and removal. Applying a light sand topdressing at a rate between 100 and 150 pounds of sand per 1,000 square feet every seven to 14 days during the growing season will help dilute organic matter as it is deposited and help smooth the putting surfaces. Given the density of Poa annua putting surfaces, it is common to see a light grooming performed ahead of topdressing so that sand can be more easily worked into the turf canopy.

Aeration programs that target different depths of the soil profile are typically effective for managing organic matter and promoting soil gas exchange. A combination of vertical mowing, traditional aeration with hollow or solid tines, and solid deep-tine aeration are commonly performed at facilities with high-quality Poa annua putting greens. It is typical for a spring and fall aeration to be performed but these practices must be based on the specific needs of the putting greens. The USGA article “New Trends In Aeration and Organic Matter Management” offers a deep dive into many of the strategies being used by superintendents to develop effective cultural management programs.

The benefits of a sound cultural management program cannot be overstated and will also have positive effects on other areas of the agronomic program. For example, research conducted at Rutgers University has shown how light, frequent sand topdressing reduces anthracnose basal rot occurrence on Poa annua greens (Murphy, 2014).

Disease and Pest Management

Anthracnose, dollar spot, Pythium foliar blight, brown patch, summer patch, microdochium patch and gray snow mold can have a significant deleterious impact on Poa annua putting greens. Depending on the location, these diseases may not all be a concern, but if Poa annua is being maintained, a preventative disease management program must be put in place to control diseases that are likely to occur because an outbreak can be devastating.

A successful disease management strategy for Poa annua greens will need to incorporate appropriately timed cultural practices and preventative fungicide applications. Online resources, like NC State’s TurfFiles and the publication Chemical Control of Turfgrass Diseases 2020, can make it much easier to choose the appropriate active ingredients, to properly time applications, and minimize the risk of developing fungal resistance.

For those managing Poa annua putting greens in locations where microdochium patch pressure is high, research conducted at Oregon State University can be used to develop an effective control program using fungicides (Macdonald, 2014). Additionally, research has been performed to evaluate alternative methods for reducing the number of plant protectant applications to control this disease (Mattox, 2020).

Evaluate which plant protectants you plan to apply to determine if a certain class can be used to control multiple diseases. For example, a properly timed application of a Qol product when disease pressure is high for both anthracnose basal rot and brown patch can result in control of both diseases. Incorporating this type of thought process before each application makes for more efficient management and better environmental stewardship.

Similar to disease control, a preventative strategy is often employed to control insect pests. Putting greens should typically be included with grub control programs in the spring. In locations where annual bluegrass weevil (ABW) can be found, additional control strategies have to be put in place. Damage from the ABW is not often an issue on putting greens but collars can be hard hit.

Control programs targeting ABW should focus on both the adults and larvae. Multiple applications can be necessary when pressure is high from these pests. Scouting must begin in the spring and continue throughout the season since multiple generations will occur.


A nutrient analysis should be conducted every year on each putting green to guide fertilizer applications. There is no one-size-fits-all program that can be applied to every golf course with Poa annua putting greens. Location, soil types, expectations and overall conditions must be given consideration when tailoring a fertility program to fit the needs of a golf course. The USGA article “Turfgrass Fertilization” illustrates how a successful nutrient management program can be developed.

When compared to creeping bentgrass, the amount of nitrogen applied throughout an entire season will likely be higher with Poa annua putting greens. Aiming for between 3 and 4 pounds of nitrogen per 1,000 square feet is a good starting point and then adjustments can be made from there. In locations where the turf is growing for most of the year, it would not be out of the question to be above this range.

A sound fertilizer program will also have a positive impact on reducing disease occurrence. For example, anthracnose is more severe when ultra-low rates of nitrogen are applied. This is just one way the benefits of a sound fertility program extend beyond providing nutrients for the turf.

Growth Regulation and Seedhead Suppression

The concept of using both fertilizers and plant growth regulators (PGRs) may seem counterintuitive, but each has their place in a successful agronomic program. PGRs will improve smoothness and consistency on Poa annua greens – especially later in the day – and they help the turf conserve carbohydrates and suppress seedheads when applications are properly timed.

Superintendents used to suppress seedheads by applying the PGRs mefluidide or ethephon tank-mixed with trinexapac-ethyl in spring. Mefluidide is a PGR many superintendents relied upon, but this product is no longer being produced. Recent research conducted by Dr. Sean Askew at Virginia Tech University confirms ethephon applications can be better timed to achieve improved seedhead control compared to a spring-only program. By making an application of ethephon in the late fall or early winter and then following up with tank-mix applications of ethephon and trinexapac-ethyl in spring, better seedhead suppression will result when compared to spring-only applications (Askew, 2016).

Spring applications for seedhead suppression should be timed by using growing degree days and monitoring local conditions. Good indicators to keep an eye on are seedhead emergence in the rough and on south-facing slopes, bunker faces and cart path edges. Soil temperatures typically increase faster in these areas causing seedheads to emerge earlier.

Should seedheads emerge on greens, cultural control through grooming or brushing is a sound approach to remove seedheads and improve smoothness. It is likely that the putting greens will need to be groomed or brushed multiple times to remove seedheads.

Typically, the focus of seedhead control is in the spring but golf courses in certain areas of the Pacific Northwest can experience seedhead emergence in the fall. Removing seedheads through grooming and brushing has been the go-to method for controlling seedhead emergence at this time of year. USGA-funded research is being performed at Oregon State University to determine if ethephon can be safely and effectively used at this time of year for seedhead control.

Once seedheads are controlled in the spring, the focus of PGR applications should shift to managing growth to optimize turf health and playability. Trinexapac-ethyl and prohexadine-Ca are the go-to options when it comes to managing the growth of Poa annua putting greens.

Research conducted by Dr. Bill Kreuser at the University of Nebraska has proven that using growing degree days to schedule PGR applications is the most effective strategy for keeping the turf consistently regulated (Kreuser, 2015). Remember that applying a higher rate of PGR, especially above what the label states, will not extend the duration of regulation.

Water Management and Heat Stress

For those maintaining Poa annua playing surfaces, success hinges on being able to properly manage water. The shallow root system of Poa annua places even more of an emphasis on water management because the turf is not taking up water from deep within the soil profile. The transition from dry to damaged, or dead, can be quick.

Moisture levels should be monitored daily with a moisture meter and any deficits corrected through hand watering or adjusting run times for each green so overwatering is avoided. Simply setting the same run time for all the greens will likely lead to overwatering and the development of turf health issues.

Wetting agents are often used to control localized dry spots and better balance the distribution of water in the soil profile. The most important concepts to keep in mind are beginning applications early in the season before localized dry spots develop and applying enough water to move the product throughout the profile. The Green Section collection “Understanding Wetting Agents” offers several resources that can be used to build an effective wetting agent program.

When weather conditions are likely to cause moisture stress, Poa annua greens will need to be closely monitored into the late afternoon. Hand watering should be performed when stress is observed. The goal is to relieve the stress placed on the turf, not completely saturate the soil profile when the highest temperatures of the day are experienced.

Should excessive rainfall be experienced along with heat stress, the importance of surface drainage, infiltration, percolation and internal drainage cannot be overstated. A sound cultural management program will improve the rate at which water moves into and through the soil profile. Ideally, some form of internal putting green drainage will be present to carry excess soil moisture out of the profile. If internal drainage is not present, serious consideration should be given to making that investment.

Ensuring Poa annua is adequately hydrated while at same time having the soil profile drain properly are certainly important when heat stress is experienced, but the overall growing environment plays a major role as well. While a shaded and/or wet environment may create a competitive advantage that favors Poa annua, direct sunlight is still necessary to drive carbohydrate production and air movement is critical to help the turf cool itself when heat stress is pushing it to the limit. Tree removal should be strongly considered to the south and east of putting greens so direct sunlight reaches the playing surface as early in the day as possible. Also, if the prevailing wind is blocked by trees, removal should be considered to improve air circulation. If trees cannot be removed or topography is creating a pocketed growing environment, installing fans will improve air circulation.

When it comes to managing Poa annua through extreme weather, it is about focusing on what can be controlled. Whether it is improving growing environments or reducing maintenance intensity, playing defense is a strength not a weakness.

Winter Injury

Depending on a golf course’s location, winter injury can be a major concern with Poa annua putting greens. Similar to surviving the summer, the most important thing is to focus on the variables that are controllable – e.g., mowing height, surface and internal drainage, fertility, and sunlight.

When it comes to deciding whether the turf needs to be covered, the benefits and risks must be carefully evaluated. Different types of covers will protect against different issues. It must be understood that the environment is being manipulated when a cover is installed, which can cause other challenges to develop. At some locations, a good sand topdressing may be enough to protect the turf through winter, while multiple covers may be required to mitigate the risk of winter injury in climates with more severe winter conditions.

The Green Section collection “Winter Injury” offers several articles that cover this topic in greater depth and can help guide decisions if winter injury is a concern at your facility.

Surface Management

The ultimate goal of the agronomic program is to balance turf health and playability so that the putting surfaces meet or exceed golfer expectations. All the agronomic practices discussed so far, along with those used to prepare the surface each day, combine to produce the putting conditions golfers desire.

When setting up the putting green mowers, a lower mowing height will produce faster speeds but the turf is under more mechanical stress. Rather than focusing on mowing at the lowest height of cut possible to produce the fastest greens, aim for mowing at the highest height possible while still being able to deliver conditions that meet golfer expectations. Adjusting the height of cut by even a few thousandths of an inch can have a positive impact on turf health and a higher height may allow for more double cutting, rolling, brushing and grooming to improve smoothness. Research conducted at Oregon State University shows how raising the mowing height and increasing rolling can be used to improve putting green performance (Golembiewski, 2011). It is a balancing act with these practices and all the other components of the agronomic program.

"Rather than focusing on mowing at the lowest height of cut possible to produce the fastest greens, aim for mowing at the highest height possible while still being able to deliver conditions that meet golfer expectations."

Tracking all the maintenance practices that are completed to optimize turf health and putting conditions can be overwhelming. Even more time consuming is processing the data to evaluate performance and make improvements. The Green Section has developed a solution for superintendents who wish to collect data to help guide their putting green management decisions.

Surface Management is a feature offered through the USGA’s Deacon platform that allows superintendents to record putting green speed, temperature, PGR applications, nitrogen applications, clipping yield and sand topdressing along with surface maintenance practices such as mowing, rolling, grooming, brushing, height of cut adjustments and vertical mowing. Once the data is entered, a series of graphs can be generated to analyze the relationships between all these maintenance practices and highlight opportunities to improve your program. Not only is this useful for agronomic planning, it is also a great communication tool when discussing putting green performance with decision-makers and golfers.


Building a successful agronomic program requires understanding how each component interacts with the others so turf health and playing conditions are balanced. A critical component of the agronomic program is monitoring the putting greens every day to evaluate performance. Ideally, every putting surface is evaluated multiple times throughout the day to determine if additional maintenance practices need to be performed.

Producing putting conditions that meet golfer expectations is a challenge no matter which type of turfgrass is being maintained because each has its strengths and weaknesses. Turf health and playing conditions can be optimized when Poa annua is the dominant turf type provided realistic expectations are set, the necessary resources are available and the agronomic program is tailored to address the site-specific challenges at a facility.

Looking for more information on managing Poa annua greens? Through our Course Consulting Service, a USGA agronomist can work with you to provide site-specific recommendations tailored to your course to ensure you get the most out of your Poa annua greens.

Zach Nicoludis is an agronomist in the Central Region.


Askew, S. 2016. “A new key to Poa annua seedhead suppression.” Golfdom. August. 31-34.

Golembiewksi, R., T. Blankenship, and B. McDonald. 2011. “Can annual bluegrass putting greens be healthy and fast.” USGA Green Section Record. February 4. 49(5): 1-4.  

Kreuser, B. 2015. “Effective use of plant growth regulators on golf putting greens.” USGA Green Section Record. April 3. 53(7): 1-10.

Mattox, C., A. Kowalewski, B. McDonald, J. Lambrinos, and J. Pscheidt. 2020. Combinations of rolling, mineral oil, sulfur, and phosphorous acid affect microdochium patch severity. Agron. J. 112(5): 3383-3395.

Murphy, J., B. Clark, C. Schmid, J. Hempfling, and R. Wang. 2014. Best management practices for anthracnose disease on annual bluegrass putting greens. Turfgrass Environmental Research Online. March/April. 13(2).

Macdonald, B. 2014. Microdochium patch disease management in PNW - 10 years of research. Oregon State University.