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Performance Greenkeeping Tasks for September

Make September a Landmark in your Club’s Future

Here we are at September already, officially the first day of the autumn months and all thoughts have turned to the autumn renovation program. The Performance Greenkeeping Tasks for September are critically important to following the Performance Greens Program. Autumn is a great time to give your green a real kick start on the program or to give your program a boost.

This year, instead of repeating the same old labour and cash intensive few days of hard work that you just need to grit your teeth and get through, why not take a step back and try to consider the actual needs of your green.

Soil/Turf Science in Balance

Your green is a living eco-system all of its own. Eco-systems, regardless of how big or small are a series of inter-connected organisms and systems that rely on each other to survive and thrive.

Conventional greenkeeping, meantime has become an expensive quest to control everything and on many greens it has failed. Routine use of preventative fungicides, high sand content top-dressings and fertilisers high in mineral salt have left many greens inert and lifeless. Greenkeeping Tasks for September and October then, have to some degree become a bit repetitive. This would be fine if the desired results followed, but in the majority of cases this can’t be said to be true.

In nature, grasslands work as self supporting eco-systems through a balance of Chemistry, Physics and Biology.

Greenkeeping tasks for September

The perfect balance of Soil Biology, Chemistry and Physics will make your job as greenkeeper very rewarding, so let’s have a look at what you can do about all of this in your autumn renovation program.

Soil Chemistry

The underlying chemistry of your soil is an important consideration and only about 2 or 3 percent of the greens I do soil analysis for have this in balance. For the majority of greens this is a good place to start.

In particular the Base Saturation of Cations is important and probably the most useful information for you in terms of soil chemistry. When I produce one of my done for you greenkeeping reports for clubs, I include a pie chart of how the Base Saturation looks.

Ideally it would look like this:


green soil analysisThe Base Saturation is the percentage of total Cation Exchange Capacity (CEC) occupied by the Base (alkaline) cations such as Calcium (Ca), Magnesium (Mg), Potassium (K) and Sodium (Na). The ratio of Ca : K : Mg when measured in parts per million (ppm) should be about 7-10 : 2 : 1 producing Base Saturation percentages of approximately 60-70% Calcium, 3-10% Magnesium, 2-5% Potassium, 0 – 2% Sodium. In most bowls and golf green rootzones the remainder are hydrogen (H) 10-15% and other cations (2-5%) providing a pH of 5.5 – 6.5.

When Calcium is depleted in the soil this has a knock on effect to the availability of other nutrients, in particular Magnesium and Potassium.

Calcium also affects the soil pH. The “H” in pH stands for Hydrogen and pH is essentially a measure of the Hydrogen ions that are present in the soil. When Calcium is low, the vacant exchange sites will be leave room for more Hydrogen ions, making the soil more acidic, lowering the pH reading. Ideally, pH should be between 5.5 and 6.5 for optimum availability of nutrients. This is the range preferred by our fine, perennial grasses.

Adding Calcium

Correcting underlying Calcium deficiency is simple and inexpensive, but can take 2 or 3 seasons to re-balance if the base saturation is well out of kilter.

When Calcium is low on your soil analysis, pH will also be too low in many cases so an application of Greens Grade Calcium Carbonate Granules will be the best route to go. This will increase Calcium content in the soil and raise the pH slightly. For a bowling green the application of 6 bags is about right.

Occasionally, I see greens where the base saturation lacks Calcium, but the pH is already within range. In this case an application of Greens Grade Calcium Sulphate Granules is the best option, as this adds Calcium without raising the pH further. For bowling greens the application of 3 bags is about right.

CEC and Zeolite

In addition to Calcium deficiencies another common problem in greens with very high sand content is low Cation Exchange Capacity (CEC). I like to see the underlying Cation Exchange Capacity measuring about 7 or above, but that is rare where rootzones are too sandy and low in Organic Matter (humus).

CEC is a measure of how well the soil can hold on to the essential nutrient elements like Potassium and Magnesium and ideally should register above 7. It is governed largely by the amount of clay and humus in the soil, both of which are commonly very low in high sand rootzones.

These problems can be overcome by adding mineral Zeolite to the rootzone during autumn renovations. Zeolite is a natural silicate volcanic mineral with unique physical, chemical and cationic exchange properties. Its three dimensional lattice allows for a very high cation exchange capacity.

Again, it is inexpensive and easy to apply.

Potassium (K)

Potassium, the famous K in the N.P.K you often see on fertiliser bags is an essential nutrient that is often lacking, due to its propensity to leaching from the soil. It is rare too, in that it is often the target of luxury uptake in turf. An unusual phenomenon meaning that the plant will just keep taking it up, even when it isn’t needed, meaning it is often depleted in the soil. A bit like opening one of those big boxes of Maltesers in my house…they go missing fast!

The correct amount of plant Potassium improves drought tolerance, cold hardiness and disease resistance, so Autumn and Winter is a key time for Potassium. It is useful to apply a high K fertiliser at this time. It often makes sense to repeat this in December or January. Two bags is the right application rate for a bowling green.


Iron build up in bowling green rootzones is often found to be excessive. This is due to sulphate of iron mosskillers and fertilisers being applied routinely for decades and where aeration practices have been insufficient.  This can result in black, wet layers and problems with plant moisture uptake due to the very high salt index of some fertilisers. With some of these fertilisers you are often adding 70grams of mineral salt for every 100grams of product. 

For greens in the renovation phase of the Performance Greens Program you might still want to apply iron to check moss ingress or to green up the turf. For this it’s better to use a more sophisticated form such as Chelated Liquid Iron, which will still have an effect on moss and green-up, but won’t build up in the soil and will be readily available to your grass plants to use too.

High Sulphate Readings

Sometimes in your soil analysis results you will see that Sulphate is excessive. This suggests that the sample was wet, which can point to problems with buried un-decomposed organic material such as old thatch and potentially black layers in the soil and this might also be a source of high Iron readings.

To tackle this, it is important to carry out aeration such as hollow tining in autumn and deep slit tining through the autumn and winter months. On very poor condition turf where rootbreak makes regular aeration difficult, you can use Liquid Aeration to increase the oxygen in the soil. This isn’t a full time replacement for physical aeration, but can certainly get you through a tough patch where you otherwise wouldn’t be able to aerate your green.

This allows an increase in the oxygen in the soil, allows any build up of sulphurous gas to escape and will increase microbial activity. The increased microbial activity can be further encouraged through the application carbohydrate rich bio-stimulants such as Molasses and Super Concentrated Liquid Seaweed. Locked up or buried organic material will breakdown more quickly in the conditions you create by doing this, improving your soil’s health, increasing CEC and making your soil more fine grass friendly.

Organic Matter

Soil Organic Matter is made up of the decaying remains of plants, microbes and animals, usually thatch in our case. Preferably, comprising around 5% of the root zone. It plays an essential role in supporting the microbial activity needed for nutrient retention and recycling, disease suppression and perennial grass growth. Physically, it provides good soil structure, drainage, enhanced root growth and promotes the water holding capacity of the soil.

In addition to the clay content of your rootzone, stable organic matter (humus) is critical to maintaining a reasonable CEC.

An intensive Compost Tea and Bio-stimulants program in autumn will help to build a more lively, microbe rich soil which will assist you in developing the green for high performance and consistency over the longer term.

This will break down thatch build up and help to convert it into fully decomposed, stable organic matter (Humus), which will also help to push the CEC upwards. 

Compost Tea is formulated to build a fungal dominated rootzone, which will naturally promote the finer grasses and discourage Poa annua (Annual Meadowgrass), minimise thatch build up and help your green to become more disease resistant and alive.


Autumn is of course a favourite time to over-seed the green. Before deciding on this fairly expensive operation, please read this article to ascertain whether or not it is likely to be successful enough to justify the cost.

If you decide that your green is in good enough condition to start over-seeding make sure you use the best quality, pre-coated seed you can get your hands on to make sure you get a great result.

Soil Texture

Soil Texture is a measure of the relative amounts of Sand, Silt and Clay present in your soil.

The Soil Texture Triangle is a tool we can use to help define what type of soil we have. In my opinion, the ideal bowling green soil (rootzone) falls into the category Sandy Loam. Let’s see how that would look on the Texture Triangle:

Image credit: Mike Norton

When your Soil Texture Analysis shows that your soil falls within the Sand or Loamy Sand Classification on the Soil Texture Triangle, this means it is already too sandy. It has gone beyond Peak Sand in my opinion, which will contribute to the soil being inert and lifeless.

Localised Dry Patch (LDP)

With very sandy Physical (texture) conditions and a low organic matter, greens will tend towards being susceptible to thatch build up and Localised Dry Patch (LDP) explained here. The areas affected in this way will be susceptible to moss invasion and shrinkage, making the surface uneven. When the turf is affected by LDP, the green will sometimes seem unable to accept water after heavy rain or irrigation even although the underlying soil will be powder dry.

Localised Dry Patch

The answer overall is to start a program that re-invigorates the soil, but there are shorter term actions you can take to combat LDP such as using Aquacept (LDP treatment) along with Hydroaid+ wetting agent as part of the autumn renovation program.

Soil Texture Influences

Soil texture influences much more than just drainage, much more than I could hope to cover here, so I have written a 5 part series of articles explaining these influences starting here:

Soil Texture Part 1 (subsequent articles link on from this one)

Thatch and Aeration

Poor levels, slow greens, bad rinks, unpredictable hands, bumps, dips and hollows. All of these are caused and exacerbated by excessive thatch at the surface of greens.

Thatch Layer
Excessive thatch

Thatch is simple the dead shoots and roots left behind by grass plants as they reproduce and die. In nature where there are no greenkeepers or fertiliser companies this is the material that is converted into essential nutrients for plants by a cast of billions of organisms and micro-organisms and it never builds up to problem levels.

In bowling greens, it can build up fast for a variety of reasons, the main one being that our overly sandy rootzones, high salt fertilisers and pesticides have made the soil inert and lifeless.

The thatch layer in the photo above can easily be depressed by 15mm when walked on, causing all sorts of problems with levels and deviations on the green surface. The thatch layer is soft and spongy when wet and hard and brittle when dry. This can quickly sap the energy from bowls making the green play slowly or cause fast and slow areas on greens that make the bowls react strangely.

Yet many clubs still insist that the way to deal with this is to add more top-dressing in an effort to level it. This is simply burying thatch which then becomes impenetrable and often hydrophobic mat.

This layer needs to be degraded and that needs a lively soil as explained above.

In many cases this layer is just too dense and thick and the whole process needs a kick start. This is the typical renovation phase explained in Performance Bowling Greens and the Autumn/Winter Maintenance Guide.

First you need to remove some of this thatch physically to give the soil a chance to take in oxygen and to create space of the soil to start the process of rejuvenation.

Here is a suggested technique to kick start the Performance Greens Program on your green:

  1. Hollow tine with 5/8″ tines at 2″ centres…leave the cores on the green.
  2. Immediately after hollow tining, use a heavy duty scarifier Graden/Sisis have suitable machines) in the same direction as the hollow tiner.
  3. Clear the resulting debris (snow shovel is good)
  4. If overseeding then do it next using a seeder that inserts the seed into the surface such as a pro-seeder or verti-seeder.
  5. Brush the remaining rootzone/topsoil material into the grooves left by the Graden.
  6. Cut the green with an old mower at about 6-7mm

Using this method you can remove around 20% of the surface and therefore a lot of thatch. You will also introduce a significant amount of air to the soil which will accelerate the natural breakdown of thatch afterwards.

The Graden will close the hollow tine holes over and the brush will ensure that the grooves are filled without adding any further top-dressing.

Some seed will remain on the surface, but the majority of it will be under the surface ready to germinate.

If your green is really thatchy, over-seeding will be largely ineffective anyway. Sometimes it takes two to three seasons of this kind of work before the green is ready for seed.

Creating a Greenkeeping Program that Works

You can use your observations of your green and the guidance in these articles to develop your own intensive renovation program for this autumn and winter.

However, if you want to shorten the learning curve and get some professional advice, please order your chemical/texture analysis here

When you do that, I will send you a kit for collecting and retuning your soil samples to the lab for analysis. You can also send me as much additional information about your green as you like and I will come back with questions.

Once the lab results are back, I will interpret them for you and write a very comprehensive report and suggested program of greenkeeping for you.

Start the Turnaround in Autumn

There is still plenty of time to make this year the year you finally make a start on turning your green around based on fact and not myth. Instead of repeating the same old labour and cash intensive few days of hard work that you just need to grit your teeth and get through, why not take a step back and try to consider the actual needs of your green.

Drop me a line if you need any help and happy renovating!

Soil Chemical and Peak Sand (Texture Analysis)
Soil Chemical and Peak Sand (Texture Analysis)
Comprehensive Chemical Analysis and Peak Sand (Texture Assessment) of your green's soil (rootzone). You will receive a soil sampling kit with instructions for taking and returning (freepost) your soil samples to the lab. The results will come back to you from Bowls Central with a full report detailing all Primary, Secondary and Trace elements, Cation Exchange Capacity, Base Saturation, Electrical Conductivity, Organic Matter, pH and your soil's position on the Soil Texture Triangle (assessed by the Laser Diffraction method and alerting you to your greens proximity to Peak Sand). Includes a full report written by a Master Greenkeeper with comprehensive 12 month greenkeeping program for your green. Unlimited support and further advice will be provided as required.
Price: £110.00
Your name, Club Name and Address please::


  1. Eric Barklem says:

    Hi John.
    I asked about apply moss killer on a recently reseeded gren, i received a email from you asking me to confirm but there was nowhere on the email to do this.

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