Key Tasks for September
Most clubs and their greenkeepers are now back into full swing. The wet and warm conditions have been perfect for grass growth. Mowing frequencies can vary from daily to twice weekly operations, dependant on the growth of the grass and the standards set by the course manager. Mowing heights may vary depending on local conditions, type of course, course expectations, sward type and mower type. The mowing heights are a guide, and will be subject to local weather conditions, but remember not to remove more than 1/3 of total grass height in each cut.
Greens. Mowing height should be maintained at around 3-6mm.
Tees. Mowing height should be maintained at around 10-15mm.
Fairways. Mowing height should be maintained at around 13-25mm.
Greens mowing frequencies should remain high, with mowers set at their summer heights. There will be an emphasis on ensuring the quality of the playing surface remains high, with many trying to attain good green speeds and consistency of roll as a priority. Dropping the height to reach these speeds is an obvious temptation, but should not generally be used as a tool to achieve this. Instead, look at utilising rollers within your current maintenance programme to ensure good speeds without placing undue stress on your sward.
Remember, do not bring the cutting heights down to more than a third of the total height of the plant at any one time. As the cutting units are used more regularly, the sharpness of the blade is of paramount importance to reduce the incidence of pressure from disease. If disease does occur, a judgement call will need to be made as to whether it will ‘grow out’ with good growing conditions, or the situation is not likely to improve.
Horizontal growth should be controlled through the use of regular brushing and verti-cutting, with the latter occurring between every two to four weeks depending on your own situation. This should help keep on top of thatch accumulation as we move through the growing season. Grooming and brushing the greens to stand up horizontal growth before mowing will encourage a denser and more attractive sward.
Hole changing should be done once or twice a week depending on golf traffic, wear or competition requirements. The first and most important is good judgment in deciding what will give fair results. Study the design of the hole as the architect intended it to be played. Know the length of the shot to the green and how it may be affected by the probable conditions for the day - i.e. wind and other weather elements, conditions of the turf from which the shot will be played, and holding quality of the green.
There must be enough putting green surface between the hole and the front and the sides of the green to accommodate the required shot. For example, if the hole requires a long iron or wood shot to the green, the hole should be located deeper in the green and further from its sides than should be the case if the hole requires a short pitch shot. In any case, it is recommended that generally the hole be located at least four paces from any edge of the green. If a bunker is close to the edge, or if the ground slopes away from the edge, the distance should be greater, especially if the shot is more than a pitch. Consideration should be given to fair opportunity for recovery after a reasonably good shot that just misses the green.
Playing surfaces should be monitored closely for signs of nutrient stress and, allied with soil sample results taken in the spring, fertiliser choices can be made to suit the conditions and type of grass/soil present. The increased growth rate will lead to accelerated thatch accumulation. Utilising the various ways of reducing this is of paramount importance to minimise the occurrence of disease and other problems further down the line.
Moisture management could also potentially be a key feature of the month. Remember not to let the soil dry out too much, but keep irrigation practices as natural as possible. Soaking the playing surface every few days is better than religiously watering at set schedules. Moisture meters are available to help you have a greater understanding of the situation beneath your putting surfaces.
Tees - mowing requirements are unlikely to be more than twice per week unless conditions are wet and growth remains strong. HOC will also remain at around 12mm for most courses but should be raised for non irrigated tees that are suffering from drought stress. Playing levels are likely to remain high, therefore daily movement of tee markers and regular divoting will be the norm to maintain good surface quality and presentation.
Any additional watering should be sufficient to aid recovery and maintain turf vigour, but largely aimed at developing a good root structure. Solid tining with no more than 13mm width tines may be an option to help with moving water quickly from the surface.
Keeping surfaces clean and free of divots and broken tees must be a daily task as well as the need to clean and maintain all course accessories.
Fairways - definition between fairway and light rough can often fade due to the dry conditions. Much will depend on the amount of rain that falls, unless of course the fairways are irrigated. Mowing is likely to be less frequent than in June and July but the HOC will remain the same, with most courses cutting at between 14mm and 17mm. At this time of year, divot damage may be slow to recover, therefore divoting of the worst affected areas may be required.
Roughs - mowing frequency of many areas of rough will be less frequent, unless it is a wet month and growth is continuing. As before, the main areas of rough are likely to be rotary cut at 50mm. Any areas of intermediate rough will still be cut weekly, but this is limited to just one or two 'bands' wide. Cutting areas of deeper rough should continue, with the aim of collecting the grass and lowering the nutrient levels to encourage the finer and slower growing grasses to thrive.
Bunker maintenance varies in the current restrictions. With growth slowing down, any edging and trimming will be slight but the focus needs to remain on stone and weed removal. Regular checks should be made regarding sand depth and distribution. If weed problems persist on sand faces, then these can be spot sprayed with glyphosate, but care needs to be taken to avoid any drift onto the surrounding banks.
Renovation to tees will be a priority this month, getting the work done as soon as possible to make use of favourable air and soil tempratures.
It is important to ensure that all materials (seed, fertilisers, topdressings) and any hired machinery have arrived and are secured and stored safely on site ready for use. Often, when ordering materials late, you may be faced with delays on delivery or not being able to get the products you want in time for your planned works.
The intensity of your renovation programme will be dependant on your individual requirements. However, it will be important to inform the members of your intentions and works programmes in advance. This will alleviate any confusion and clarify why these operations are taking place.
The objectives of end of season renovations are:
- To repair worn areas
- Prevent a build up of thatch layers (scarification)
- Restore surface levels (topdressing)
- Alleviate compaction (aeration)
- Re-establish sward densities (overseeding)
- Application of pre seeding/autumn fertilisers to help promote sward establishment
The weather will be an important element when carrying out end of season renovations; planning and timing of operations are critical. You do not want to be topdressing when inclement weather is about (during rain showers) because, once the topdressing gets wet, it becomes very difficult to spread and brush in. You have to work with the weather. Putting on too much dressing in one go will smother the turf. Keep jobs in proportion and keep an eye on weather forecasts.
The success of these renovations is dictated by a number of factors:
- Timing of operations
- Weather conditions
- Type and often the condition of the machinery used (aerators, scarifiers, overseeders and top dressers)
- Choice of materials
- Knowledge and experience of the persons undertaking these works
- Budgets available
If you do decide to use external contractors to carry out your renovations, ensure you have checked their credentials and that they have the relevant skills, experience and machinery to do the job. Obtain references.
Timing of operations:- the earlier you can get on with your renovations the better (mid September through to mid October are usually optimal times for renovations). It is important to make good use of the warm soil and air temperatures that will aid seed germination. Also, there needs to be some moisture in the ground to allow adequate penetration of both the scarifiers and aerators.
Weather conditions:- it is important to work with the weather conditions, particularly when applying and spreading topdressing materials, the surface needs to be dry. However, there needs to be adequate moisture in the soil profile when applying granular fertiliser products so that they become activated and soluble, enabling them to be taken up by the plant.
Types of machinery:- choice of machinery is vital for successful renovations; ensure that scarifiers and aerators are fit for purpose and that the blades and tines are sharp, clean and of correct length. Also, check that they are safe to use and have the appropriate guards fitted. There are many different makes and models of machines available, all of which offer different techniques or modes of action. Some scarifiers are more aggressive then others.
Ideally, you need to take a soil profile of your green and measure the thatch layer present. If it measures 10mm, you will need to ensure the scarifier is capable of operating to this depth, therefore being able to eradicate the thatch layer you have.
Aerators come in many different forms, offering different tine spacing and depth and size of tines. Again, you need to choose the appropriate aerator for your needs. In most cases, the biggest factor dictating the club's choice of machinery is often what they have or what they can afford to hire.
Choice of materials:- it is important to ensure you use compatible topdressing materials. Changing materials can often have disastrous results. Layering of different materials can cause root breaks and interfere with the hydraulic movement of water through the soil profile.
Seed should be used from approved suppliers and be certified. The use of old seed (more than twelve months old) may decrease its germination rates.
Mow the greens and tees before commencing renovations to clean up any surface debris.
Scarify to remove unwanted thatch. Collect and dispose of debris. Depending on the severity of the thatch, you may need to scarify several times in different directions. However, in most cases, if regular verticutting/grooming has taken place during the growing season you would probably only be required to scarify in two directions. Do not scarify at right angles to the previous scarification line.
Depth of scarification between 4-15mm depending on depth of thatch to remove. The mower can then be used to clean up the green after scarifying has been completed.
Aerate to relieve compaction and encourage root development. Aeration is the decompaction of soil, improving air and gas exchange in the soil profile. Depending on the turf's condition, you can choose to carry out hollow or solid tine spiking. Hollow tines are generally used on a bi-annual basis or when you have a severe thatch problem.
Depth of aeration will be determined by the depth of your soil profile and what problems you want to rectify. Hollow tining is best achieved to a depth of between 75-100mm. Solid or slit tines can be set to penetrate deeper, ideally between 100-300mm.
Top dressing restores levels and improves surface drainage. Ensure you use compatible top dressing materials, sands, sand/soil mixes. Spreading can be achieved by several methods, utilising pedestrian or ride-on, disc or drop action top spreaders, or by hand using a shovel and a barrow. Best carried out in dry weather. It is important that the topdressings are spread uniformly.
Brush to incorporate dressings and to help the grass stand back up; brushing in with a lute or drag brush/mat to restore levels.
Overseeding restores grass populations. It is important to ensure a good groove or hole is made to receive the seed, good seed soil contact is essential for seed germination. Good moisture and soil temperatures will see the seed germinate between 7-14 days.
Fertilising provides nutrients for grass growth. Apply a low N nitrogen fertiliser product, something like an Autumn Fertiliser NPK 5:5:15 to help the sward through the autumn period.
Watering/Irrigation:- it is essential to keep the sward watered after renovations to ensure your seed germinates.
Another month has flown by and September is now upon us. This month traditionally sees a shift in weather conditions, which become more autumnal, with less extreme heat and cooler temperatures, and more frequent rainfall. Mornings and night become noticeably darker and, importantly for turf managers, dew on the grass plant becomes a more regular occurrence.
August’s weather has provided good conditions for those who have carried out any maintenance, with positive conditions to promote recovery. There has been a mixture of good temperatures with sunshine and showers which has maintained soil temperatures and provided plenty of moisture for germination after seeding.
September looks set to continue from August, with conditions still favourable for any renovation work planned. Therefore, those who couldn’t get this work done in August will still have a good opportunity for success this month. These conditions will also continue to provide strong growth and recovery from areas with high play. If overseeding work is being carried out, ensuring good contact with the soil will allow the seed to utilise the moisture in the ground. Plant growth regulators such as Prohexadione-calcium and trinexapac-ethyl can be used at this time to help in the development of new seed by holding back the competition from existing mature plants in the sward, creating a more favourable environment for establishment.
As moisture levels increase in the soil and on the leaf, this favours disease development, as the 3 parts of the disease triangle start to come together. For many this will play a major part in planning over the coming months, alongside carefully selecting the right nutrition. As we enter this period when conditions become far more conducive for disease development, with heavy dews, less sunlight, more shade etc…. management of these stress factors becomes essential. Moisture and water management are key in restricting disease development and utilising applications of dew suppressants, even if short-lived, can be just enough to tip the balance in your favour in the right conditions. Similarly, penetrant wetting agents can assist in allowing water to easily move through the profile. However, consideration should be given to the make-up of the soil profile and how effective these can be in certain situations. Once any renovation work is complete, ensuring the cutting units are sharpened and providing a clean cut will also help reduce any potential weak entry points that a pathogen looking for a host is likely to exploit.
Providing adequate nutrition to promote recovery from any maintenance work, or to keep growth consistent and strong to support producing quality surfaces, are factors to consider.
Once any new seed has run out of its own supply of nutrients, ensuring there is adequate supply will assist it getting better recovery. Including a suitable amount of phosphorous helps supply energy to synthesise ATP. A healthy amount of Calcium will not only strengthen the primary cell walls, fortifying defences against pathogenic fungal attack, but also encourage cellular generation at the growing tips of roots and within new leaves.
Applications of high levels of nitrogen can further encourage disease outbreak. Research shows that selecting a balanced autumn fertiliser can consequently result in better spring performance. As such, over applying at this point in the season is likely to lead to excessive soft leaf growth, which is more susceptible to disease attack. Choosing an appropriate nitrogen source that will provide a staged release of nutrients, as the conditions are suitable, will maintain turf health and strengthen against disease attack.
The Emergency Authorisation for Acelepryn for control of Leatherjackets has now been confirmed and this can be purchased now, once the stewardship form has been completed. This applies to golf courses, airfields and racecourses only. The latest time for application is 29th November. Remember - Acelepryn is most active on the 1st and 2nd instar stages and therefore timing is critical to maximise success.
Application of the product for control of adult Chafers has now passed and should have been completed by 31st August. Where chemical control is not authorised, entomopahogenic nematodes can be applied, with warm soil temperatures and available moisture being ideal conditions to get the best out of an application. The entomopahogenic nematodes swim in the water film on soil particles in their bid to search out a larval host.
The adult crane fly typically emerges in late July to September. The adult flies commence egg laying almost immediately, with hatching and larvae emergence about two weeks later. You can check reported sightings of crane fly species on the Pest Tracker on the GreenCast website. To aid effective timing of treatment, ensure the product is in the soil at the optimum time for egg hatch and initial larvae activity.
With the increased moisture content in August, worm activity has started and is already causing issues for turf managers. There are still no legal controls for earthworms and any product which is applied to directly affect them is done so illegally. Cultural management continues to be the only route currently available, which can include a combination of practices such as localised surface acidification, removal of grass clippings to reduce their food source and sanding of surfaces to assist in the drying out and dispersal of casts, leading to less negative lasting impression on the surface from the cast.
At this time of the year, it is important that all machinery is in good condition and well maintained. Machinery downtime, due to lack of maintenance or poor set-up, can be costly. As the weather continues to improve, you will be all-out to keep your course in tip top condition.
Courses with their own workshop and mechanics will be at an advantage. Those without such luxuries need to be ahead of the game - all machinery should have been serviced and back in action by now.
Having a good wash down facility is an essentail tool for keeping equipment clean; it is a wise investment.