Expected weather for this month:

Unseasonable mild spells forecast, interspersed with cold snaps

Key Tasks for December

After autumn renovations, most course managers/greenkeepers will be looking to increase mowing heights on greens and tees by 1-2mm, with many factors dictating the height of cut - soil type, grass species and golf traffic.

Other tasks that complement this work involve the use of grooming and verticutting units to remove unwanted thatch and side shoot growth.

Mowing frequencies will 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. The less stress that is placed on the grass at this vital time the better the results further on into the next season.

Greens. Mowing height should be maintained at around 6-8mm.

Tees. Mowing height should be maintained at around 10-15mm.

Banks. Mowing height should be maintained at 22-30mm

Fairways. Mowing height should be maintained at around 15-25mm.

Rough, semi rough grass areas. Mow and tidy up these areas. Reduce build up of clippings by cutting little and often with a rotary or flail. Mowing height will depend on type of course and the standard of play required. Height of cut during the winter between 50-100mm.

As we progress through the month, air temperatures are likely to lower, with many courses experiencing morning frosts. It is important to prevent people from walking over the grass surfaces (preventing surface damage to the sward) during frosty conditions. Courses should be kept closed if possible during heavy frosts. The decision to close the course, or parts of the course, should be down to the Course Manager/Head Greenkeeper. Effective communication is essential to inform all parties of the decision. This is usually in the form of signage and messages to confirm the reason and the expected time the course, or parts of the course, will be closed.

This may also involve the restriction on using buggies and, in some instances, trolleys on the course. Winter tee mats and temporary greens may also come into play, with many golf courses resting their competition tees and greens.

Changing of holes should be carried out regularly, however frequency will be dependant on a number of factors, green size, green construction, tournaments, amount of play and condition of the green.

During wet periods, it is likely the hole will wear more quickly, resulting in a crowning affect and surface wear. This wear is more apparent if the green has thatch problems. The hole will tend to wear quickly and form a depression caused by the placement of the golfers' feet. You may be looking to change the hole positions more than three time per week during wet periods.

Fertiliser programmes are not generally carried out after November due to the change in air and soil temperatures as most turf grasses usually start to become dormant, slower growing. However, some greenkeepers may apply some liquid iron to keep the turf healthy and strong. USGA greens often do require some top-up feeding during the winter to maintain the nutrient status of the green.

Inspect, weed and rake bunkers. Repair any damage from rabbits or other animals, maintain sand up the face of the bunkers to prevent erosion and sand loss.

Some golf courses experience flash floods during heavy rain fall, leaving many bunkers in a poor state (washing out sand from bunker faces). Repair works may be necessary.

Bunker construction work may be ongoing in December, subject to ground conditions allowing for transport of materials around.

Aeration of tees will continue throughout the winter when weather conditions allow. A wide range of solid or slit aerators are put to use on the greens. It is essential to keep the greens aerated to maintain air and gas exchange in the soil profile, thus improving the drainage capabilities of the greens.

Aeration of tees will continue throughout the winter when weather conditions allow.

When the ground conditions are favourable, aerate fairways with solid tines to increase air and gas exchanges in soil profile. Encouraging deeper rooting of fairway grasses is important. Deeper rooted grasses are more likely to overcome stresses during the following year.

The weather forecast for December is for fluctuations. Periods of unseasonably mild weather interspersed with cold snaps. Nothing too prolonged is predicted over the course of the month, particularly with respects to cold spells which are more likely to occur throughout January and February once the storage heater effect of the North Sea’s residual summer heat has receded, such that it can no longer have a warming affect upon cold easterly air streams moving across the British Isles and into Ireland.

It is likely to be a roller coaster month of peaks in growing potential for both grass plant and fungal pathogen alike, followed by dips of activity, first in the plant and then in the fungal pathogen as temperatures fall.

Looking at the pros and cons of each scenario they can broadly be summed up thus:

Warmer Period

Pros: If soil temperatures rise above 10 degrees Celsius, then good growth will promote recovery on disease scars and worn areas, as well as push along seeded areas following renovation events during early autumn.

Cons: Warmer conditions which promote growth can encourage fungal diseases, especially when they occur alongside high relative humidity and low air movement.

Colder Period

Pros: Once temperatures drop to zero or below, fungal diseases will also draw to a halt.

Cons: Grass growth stops once soil temperatures hit low single figures, thus reducing recovery and establishment growth. In addition, cold conditions place an abiotic stress demand on the plant leaf tissues.

Sitting somewhere between warmer and colder are what can be defined as cooler periods where temperatures sit between 5 and 10 degrees Celsius. It is these periods when the grass plants metabolic systems are beginning to grind to a halt, but the fungal pathogens systems are still driving onward so that surfaces are at high risk of becoming infected with diseases such as Microdochium nivale.

Following the withdrawal from use of iprodione in June of this year, and consequently the formulations Chipco Green and Interface, this disease season marks the first year turf mangers are faced without a fungicide which will target visibly active Microdochium nivale and stop it in its tracks. Instead, the active substances available need to be applied to surfaces before the disease is active, none more so than the active substance Fludioxonil.

Fludioxonil is an antisporulant which acts upon dormant spores on the plant surface and in the rootzone. Fludioxonil interferes with the water pressure in fungal spores causing them to burst and die before prevailing environmental conditions are suitable for promoting their germination. Due to the fact that it does this outside of the plant's physical structure, Fludioxonil does not have a systemic action which requires plant metabolic function to become effective. Rather, Fludioxonil operates outside the plant when it comes into direct contact with dormant fungal spores. 

Understanding the basic principle of a relatively straightforward mechanism by which an active substance operates upon a fungal pathogen (Fludioxonil makes dormant spores burst) allows for greater consideration of effective application timing. For example; given this knowledge, it is clear that an application of Fludioxonil once spores have germinated and then infected a plant, thereby causing visible signs of damage, is somewhat akin to bolting the proverbial door once the horse has bolted.

On the flip side, an application of Fludioxonil prior to an outbreak of fungal disease – as the result of reference to historical records and checking of upcoming weather patterns and forecasts which indicate disease is highly likely to occur – would serve to remove dormant spores eagerly lying in wait for conditions to favour them.

Additionally, combining the antisporulant action of Fludioxonil alongside the plant cell wall-strengthening action of foliar calcium would further help to fight off disease by providing the plant itself with the resources it requires to bolster its defences.

Finally; combining these actions with good old-fashioned principles of aeration, to allow the soil to respire, and dew removal to inhibit the fungal pathogens ability to grow and infect across the leaf surface, and you have before you the core fundamentals of an Integrated Pest Management Plan for combating fungal diseases on sports turf in December.  

One quick word on soil water management, where surfaces are prone to water logging; then consider the use of a penetrant wetting agent to drive moisture away from the surface; not only will this reduce surface humidity, helping to mitigate pathogen attack, it will also allow the soil to maintain effective respiration which reduces stress on the plant and helps to maintain populations of beneficial microorganisms.

Finally, be sure to investigate areas which were dry in the summer; do not presume moisture will have yet penetrated at depth, and consider that if not sufficiently rehydrated over the winter, soils will start drier in the spring. Should another dry summer come to pass, the onset of water stress will become apparent sooner, again a penetrant wetting agent will help to alleviate this problem.

When looking back at weather records over the past forty-five years, summer 2018 may be considered something of a freak occurrence; however, inspection of weather records over the past five to ten years indicates such extremes are becoming more and more common. The lesson then is not to presume spring and summer 2019 will not be similar to 2018, it may very well turn out that way.

As always prior consideration and then adequate preparation for a range of potential extreme scenarios is paramount to maximising sustained quality of turf surfaces throughout any given year.

It is important to maintain machines by carrying out regular servicing and repairs.

As grass growth slows down, use the time to take some machines out of operation for an overhaul.

  • Inspect and clean machinery after use.
  • Maintain a stock of consumables for your machinery, replace worn and damaged parts as necessary.
  • Secure machinery nightly with good storage facilities and strong locks
  • Record makes and models and take pictures of your equipment as additional referencebetter still, take pictures of your equipment.

Inspect drainage outfalls, channels and ditches. Ensure that they are working. It is during the winter months that most golf course managers/greenkeepers can evaluate the condition and performance of their drainage systems.

Inspect, check and empty all litter bins

Time to organise winter servicing of machinery

Keep stock of all materials

Tidy mess rooms and sheds

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