What is Poa (Poa Annua) on Sports Turf is a blog that looks into the impact, management in the prevention of this weed grass on turf surfaces- for cricket pitches, golf courses and all sports surfaces.
The lifecycle
Poa is also more commonly known as annual meadow grass. Poa grows through the year, but is often called an annual as it completes it life cycle in a year. Poa can die off in the heat of summer due to heat stress, as Poa is shallow rooted and the first to show sign of stress and suffer during periods of drought.
Due to the list of negatives below, Poa (annual meadow grass) is known as a weed grass, there is one positive though it does fill in where areas are bare and thought a arguable topic, poa grassed canopy is better than no grass canopy for those who do not have budgets to overseed in there roles in turf management.
The Negatives of Poa in Turf Management?
These are just a few negatives that come to mind, the fact that Poa is shallow rooted and requires higher water levels along with being stalky in nature, if not controlled is the perfect environment in creating thatch.
- Poa is shallow rooted, so prown to divotting and die off during heat stress
- Its clumpy stalky growth habit, is thatch forming
- Stalky nature can make for uneven sports surfaces, especially some sports
- High watering needs as shallow rooted
- Can create higher levels of thatch and in turn more disease and a increase in turf pests
Prevention
Prevention is really hard as Poa can blow in on the wind and is very good at establishing within your grassed surfaces during periods of turf stress. The below preventions will help manage the negatives of Poa and help reduce the spread
- Regular in season verticutting, to encourage and densely packed grass canopy of your chosen grass species.
- Brushing/Verticutting and collection of Poa seed head when flowering will help slow the spread of these very small weed seeds
- Don’t cut too low as annual meadow grass often is looking for an opening in the grass canopy and grass cut too short under stress can create that environment
- Thorough end of season renovation in terms of scarification and in turn appropriate seed rates to outcompete and prevention Poa from taking hold.
- Promote a healthy grass canopy with balanced nutrition (avoid too much Phosphorus) and a deep-rooted plant
- Improve the surface drainage capacity of your soils, where feasible
- On winter sports pitches keep surfaces aerated especially on heavy soils, as Poa love wet feet so keeping surfaces free draining will help discourage this weed grass.
- Primo Maxx is a growth regulator which has been used in turf management for some time to slow down the spread of Poa, by means of stopping the plant from seeding and spreading, but this will not eradicate the plant itself.
Further Reading- What is Vert-Cutting
Eradication of Poa (Annual Meadow Grass)
The only way to control Poa completely is by eradication of the weed grass, by mean of weed control or complete removal, some people try to starve out the population of Poa but unless you fully remove the left-over thatch and fully overseed you could create as many problems as you solve.
Eradication of Poa Options
Complete removal of the shallow rooted plant by means of Fraise mowing or and Koro fielding top maker, a full reseed would be required with increased seed rate from a normal renovation, depending on what option you take (fraise/koro)
An application of a total herbicide a couple of weeks before the end of the season by someone licenced operator to spray such chemicals. A high level of scarification and overseeding will be required after
Want to know more above Koro vs Fraise Mowing
Summary
As a working groundsperson l know first hand the challenge of Annual Meadow Grass, my own view is manage it for a long as you can till it starts to become unmanageable then look at eradication processes.
As example, if you eradicate it from your square as a example but not from your outfield which is unlikely due to cost restraints it will slowly creep back onto your square, but machinery, by foot and by air. As l say my take on it is manage it, live with it, discourage it and look to eliminate it only once it becomes unmanageable.
PS – I would love to here from you and your own experiences on managing Poa on your sport turf, please share in the comments.
