August Maintenance

How often you mow this month will depend on what resources you have available at your club. In an ideal situation, mowing will be carried out every day or no less than three times per week. You need to mow regularly to ensure the sward height is maintained at between 4 and 8mm.

At some clubs, the mowing height may be reduced further, even as low as 3mm to speed up the greens for competitions, but regular mowing at this height will cause plant stress.

Other factors will impact on the speed of greens. Too much thatch is one main cause of slowness while a lack of topdressing can also contribute.

Bowlers will often complain about slow, inconsistent greens and as a result clubs speed them up by shaving off more grass. While this may boost speed in the short term, the long-term effects are damage to the green.

This month, carry out the following tasks:

  • Remove and control how quickly thatch and side growth - unwanted vegetative growth - grows by grooming and verticutting regularly
  • Topdressing needs to be applied lightly to restore and maintain surface levels as this will also increase green speed
  • Mow in several directions as this will reduce nap layering and increase green speed
  • Control how much moisture is in the soil to influence green speed
  • Brush and switch the playing surface to keep the green clean by removing dew and surface water. A dry surface is one that is resistant to disease

Mowing: Don't be tempted to cut below 4mm - despite what the members may want - unless you have the expertise, resources, and knowledge to support this regime. The cost of giving members fast greens can be inflicted suffering on the greens - cover will thin out, bare areas develop and then weeds and mosses can establish. Underneath the surface, constant rolling will have resulted in compaction of the soil profile and the air spaces will have been reduced. Poorer root growth results, so water does not move freely and flooding can happen.

Often, a bowling green will be slow because of the presence of a layer of accumulated organic fibre which is commonly known as thatch. This sits just below the surface and its cause is the build-up of matted grass stems. It is easy to detect as the surface will feel soft as you walk across it.

Aeration: This is a key activity as it maintains a good air/gas exchange in the soil profile. Use a sarel roller of depth 5mm to keep the surface open but not disturbing the playing surface. Aerate more deeply when moist conditions allow penetration with micro tines.

Irrigation: Water is key to all chemical, physiological and biological processes of plant growth and the relationship between soil and water is vital to any grass plant's sustainability. You need to understand these relationships and all grass plants are a continuum of water movement. More than 90 per cent of the water requirements of a plant is transported through the plant from the soil profile, via the roots and stem tissues into the leaves and then into the atmosphere. By having knowledge of these relationships you can design and operate effective irrigation systems. You are aiming to achieve a water balance within the soil profile to ensure that the grass plant can access the water available in the soil.

Irrigation scheduling by the water balance approach has as its foundation estimating the soil water content. In the field, daily evapotranspiration (ET) amounts are withdrawn from storage in the soil profile and any rainfall or irrigation is added to storage. If the water balance calculations forecast soil water dropping below some minimum level, then irrigation is indicated. WatherWeather forecasts help predict ET rates and projection of soil water balance to give an indication of whether irrigation is needed imminently.

What will affect the soil water balance? The following factors are crucial:

  • Soil type and condition as the holding capacity of soils will depend on their classification. Clay soils will hold more water than loamy or sandy soils so soil type will effect and contribute to how much water is required. Soils continually go through phases of wetting and drying which are caused by the weather
  • Turf type and condition as healthy vigorous turf will transpire more than an unhealthy plant
  • Time of the year because as there is more soil water present during the spring, autumn and winter when cooler temperatures combine with higher rainfall
  • Weather - from air temperature to daylight hours, solar energy inputs, wind speed and shading, there are many factors that affect ET rates
  • Maintenance regimes. Keeping the soil open and aerated will increase the soil's drainage capacity. However, compacted soils will prevent water being able to move through soils and can create an environment that stops water reaching the soil profile. Carrying out effective regular maintenance regimes which include aeration, scarifying, harrowing, brushing, top dressing which all help to keep the soil in excellent condition
  • Irrigation system - the type, capacity, running time, calibration and effiiciency can all play a role
  • Water resources and both quantity and quality. How much water you have available and the amount licensed for use in any one year will determine how any system performs.
  • Facility - its type, design and construction will all play a role. USGA greens perform differently to pushed up soil greens and each have different water and management requirements. Modern drainage systems also have an impact on soil conditions - extensive systems will frrely drain water from the soil.
  • Groundsman knowledge - you need someone who understands the parameters above and who can access the water requirements of the turf to correclty put in place the correct irrigation schedule for the facility.

The relationships between the soil and water are key drivers in maintaining a healthy plant, so make sure you readily water your bowling green and don't let the plant become stressed through lack of water. However, don't water too much, as this can cause problems too.

Fertilising: Continue fertiliser treatment and turf tonics in accordance with your existing annual programme. If you have no fertiliser programme, get your soil tested and it's always good advice to use an independent soil analysis company so your results are impartial.

Feed regularly as this is essential to keep colour, vigour and well-being in your sward. Combine slow-release granular based fertiliser, topped up with some organics/liquid feeds for what is becoming a popular method of feeding greens. This slow release will last about three months and the liquids can be applied every four to six weeks depending on the requirements of the plant.

Use wetting agents as a preventative cure for dry patch and these are now being used regularly on fine turf by groundsmen on a monthly basis. There are three forms of soil wetting agents available - Residual, Penetrant and Curative.

Residuals continue to work over a stated period, dependent on the amount of time you require to work it in whey hold water near the surface.

Penetrants assist in the removal of standing water and move water through the profile. Turf managers are now using penetrants in a tank mix while using other chemicals to get the product through the profile as quickly as possible.

Curatives take on the problem of dry patch, stripping off the waxy organic coating on the soil particle to make the soil profile water repellent. However, this doesn't completely address the problem because each time you topdress with sand, another layer of of water repellent organic coating is added to the soil profile. Some believe this type of wetting agent also removes beneficial bacteria from the soil and can be seen as controversial. An interesting statistic is that using curatives can reduce water consumption by up to 30 per cent.

All factors contributing to dry patch need to be addressed to get the best out of using wetting agents. Look at alleviating compaction, removing thatch, and stopping the rootzone from reaching the critical moisture content by irrigating evenly and regularly.

To achieve best results, take a programmed approach to applying wetting agents, beginning early in the season before symptoms develop and remember that blanket applications are also more effective than spot treatments.


This month is a good time to apply another round of fertiliser. With a two-month longevity an application now will last until October, which is the perfect time for an autumn winter feed. This will provide a kick of phosphorous, potassium and magnesium which will boost the plant's resilience and colour without providing excessive nitrogen which would encourage soft lush growth.

Any risk of severe drought stress has now passed and we tend to see plenty of rain in August. This moisture, in combination with warm temperatures and humidity will stress the plant from several directions. It is therefore key to aerate to maintain a balanced soil/oxygen ratio. Use 8mm or 12mm standard tines down to a depth of around 200-300mm with a vertical aerator to help the soil breathe. Combine with a weekly pass from a Sarel or Star Tine aerator which will provide aeration at large volume into the sward and thatch layer to provide a rounded aeration approach.

Continue to use polymer and penetrant wetting agents to manage soil percolation and retention by moving rainfall away from the surface and holding it further down the profile where it can be readily available to the plant during hot and sunny spells.

We have seen unseasonably high disease pressure in July and we can expect this to continue through August with both microdochium patch and anthracnose forecast to cause problems.

Heritage Maxx is a good choice for use as a preventative and early curative as it has a systematic action which makes it a sensible option during the growing season and useful as a preventative ahead of turf renovations. As red thread will also thrive when it is humid, get on top of this by keeping the leaf as dry as you can by brushing and switching.

Seaweed can also boost soil flora, as it primes the plant so it can resist environmental stress and extend the longevity of fertilisers. Nevertheless, it is also an excellent fungal food and stimulator so you need to time applications carefully so they boost good fungi and not ones that are pathonogenic. Keep a close eye on weather trends and only apply about a week after fungicide application.

Weeds, pests and diseases

Brush and sweep regularly to keep the surface open, clean and dry as this will aid disease resistance. Look out for any attacks of fungal disease and use approved fungicides to treat infected areas.

You can control broadleaf weeds with a selective weedkiller but the timing of when you apply is key - make sure to apply when weed growth is vigorous. As renovations will start in September, eradicate any weeds now using one that will combat the specific problem you are faced with.


Make sure you take good care of your equipment and store it safely and securely. Get into the habit of washing down and cleaning each time you use your machines. Keep equipment clean and well serviced and keep blades and cylinders sharp.

Dennis Mowers