Poa vs Browntop

There's been a lot of talk over the last few years about the conversion of the greens from Poa to Browntop. Many debates have taken place as to the benefits and value of the continuation of this program and whether or not it should be continued. Certainly, strong views exist as to peoples personal preference but there also seems to be an element of misunderstanding forming the basis for some opinions.

Lets take this opportunity to try and introduce some good information about the pros and cons and offer some behind the scenes type insight into this discussion.

Whats the difference?

Good question.

A Poa Annua plant with visible seed heads

Poa, (Poa Annua for those who enjoy botanical names) is an annual grass species capable of invading and existing anywhere conditions are favourable. A prolific seeder (estimates of up to 200,00 seeds per square metre), poa germinates in Autumn when temperatures cool and consistent moisture is available. Present through Autumn, Winter and Spring, Poa seeds in Spring before temperatures become too hot (sustained above 22 degrees) and the plant dies. Small white flowers can be present and this is one of the key identifying features along with its yellow/green colour and bunch type growth.


Browntop (Agrostis Capillaris) is a perennial grass species with numerous cultivars of which several, such as Egmont and Manor, are suitable for golf turf. A cool season grass, Browntop exhibits strongest growth with air temperatures between 18 and 22 degrees Celsius. When temperatures exceed this continuously, the plant can enter a state of dormancy which is not to be confused with the death of an annual plant such as Poa. Prolonged cool temperatures result in slow growth and possible winter dormancy during sustained periods below 0 degrees. Browntops ability to grow laterally means it can, with time, fill in voids around it. Blue/green in colour, it can also be differentiated from Poa due to its slightly wider leaf blade.

So how does this affect my golf?

For a number of decades, Hamilton Golf Club had putting greens comprised of essentially 100% Poa. Certain times of year, primarily Spring and Autumn, this resulted in extremely good surfaces that were noted for their speed. Conversely, at the other times of year the surfaces didnt perform so well and soft bumpy greens were the norm. This was largely due to the need for excessive water in summer to keep the grass alive and due to thatch that held water in winter. The variance in surface quality from morning to afternoon was significant.

A decision was made that priority be given to producing a more consistent surface that performed better for longer periods of the year with acknowledgement to seasonal variations.

Through research and consultation with independent advisers, the Club opted to embark down the path of a grass species conversion. Browntop was identified as having key advantages over Poa that would help to reach their goals.

What are the advantages?

Another great question

Browntop, as a plant, has a much lower requirement for fertiliser and water which were inputs identified as having a significant contribution to the thatch problems. Also, being a perennial and having a much better tolorance of heat and drought conditions, Browntop lends itself to being more manageable during the hotter months. Coupled with its comparative lower requirement for fungicides and other chemical inputs, weight was also awarded to the financial advantage of changes grasses.

Ok, so science stuff aside, the greens have been kinda rubbish. Why?

The conversion began about 10 years ago and some great work was done introducing the Browntop and changing management strategies to reduce the Poa. Early on progress was fairly rapid and although people had to experience some discomfort, the initial results demonstrated that it was worth the effort. Poa is however a gnarly little bugger and has the ability to adapt quite quickly to changes and therefore the rate of progress naturally slowed over time.

Understandably, last year questions were raised at the AGM as to an expected time-frame for the process to be completed. The feeling was, things had taken longer than was perhaps intimated they would take and members were keen to see an acceleration and an end to the ongoing discomfort.

Like the saying goes, you need to breaks the eggs to make the omelette.

So we broke some eggs.

As summer approached, the anticipated hotter temperatures were identified as a way to exploit the advantages Browntop has over the Poa and this would be a great opportunity to let nature contribute to the process.

Lots of Poa + no water = Crispy putting green

As you can see in the photo above, when we removed the water the Poa was prematurely pushed to the end of its life cycle. This was particularly apparent in the putting green which had in excess of 60% Poa.

The Browntop is still healthy while the Poa battles

The next step was to take advantage of the warmer temperatures and seed Browntop into the areas where the Poa had been in an effort to fill the voids with our desired grass before the Autumn germination of the Poa occurred. This involved lots of small holes being punched (by hand at times!) for us to seed into.

Holes punched for seeding                                    New seed appearing

This worked really well for us and we were able to introduce Browntop into a lot of selected areas where it was needed. This should reduce the opportunity for Poa to re-establish due to the density providing less bare areas for it to germinate.

Newly established Browntop in the putting green filling in nicely!

Cool story. Now what?

Like anything living thing, there are never any guarantees and you are always working with certain factors outside of you control. As the cold progresses, the Browntop growth will slow down which will mean some Poa will be able to come back in in Spring. It wont be anywhere near the levels that have been present in the past and now we have good populations of Browntop we will be able to manage it out sooner. This will continue through careful water and nutrient use and the selective application of agrichemicals. We don't anticipate any turf loss on the scale we experienced this past Summer as we have made strong progress which will position us better. There will/may be a small amount but it is important to appreciate that this is often deliberate and very much a short term pain long term gain situation.

Good Golfing

The Maintenance Team

Hamilton Golf Club


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