Key Tasks for December
November was a difficult month for many courses, with waterlogging reported in a lot of courses around the country. As ever, the advice below is very much weather dependent; with frost or flooded areas, it is better to keep off.
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.
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.
December brings with it some mixed blessings: the need to contemplate relatives, gifts and cards whilst controlling alcohol intake over Christmas and the New Year. Meanwhile, it can be seen as the low time within the growing calendar which can be a tricky time to navigate from a disease and weather perspective.
I don’t need to remind you how wet it has been, almost from the end of September, though it’s useful for us to think about the implications of all that water for both the plant and for the substrate it’s rooted in.
The need to take a breather
Much of the life that we are familiar with uses oxygen in a process called respiration, and that includes microorganisms within the soil. Conventionally a well-structured soil will contain roughly equal parts of water to air contained within the pore spaces. This provides an environment for organisms such as worms, fungi, algae, protozoa, bacteria and nematodes. Some of these are mobile but many have restricted ability to move meaning that the environment largely determines which suite of species can exist – if the soil structure is compacted or waterlogged for periods of time then anaerobic species, organisms that don’t require oxygen, will be the dominant form of life.
Bacteria vary in size from around 0.2 µm up to 10 µm making them a comparable size to clay and silt soil particles (< 0.2 µm and 2-50 µm respectively). They grow and live in thin water films around soil particles and near roots in an area called the rhizosphere. Bacteria’s small size enables them to grow and adapt more rapidly to changing environmental conditions than larger, more complex microorganisms like fungi which tend to prefer more acidic environments without soil disturbance.
Most microbes are generally inactive and may only have a short burst of soil activity. Since bacteria live in difficult conditions they reproduce quickly when optimal water, food, and environmental conditions occur. Populations of bacteria may easily double in 15-30 minutes. Soil oxygen levels often determine soil bacteria activity with most soil bacteria preferring well-oxygenated soils. Examples of aerobic bacteria include the Aerobacter genus which is widely distributed in the soil and actinomycetes bacteria genus Streptomyces which give soil its good “earthy” smell.
Anaerobic bacteria prefer an environment without oxygen. Many pathogenic bacteria prefer anaerobic soil conditions and are able to outcompete or kill off aerobic bacteria in the soil when conditions are suitable. Bacteria populations expand rapidly and the bacteria are more competitive when easily digestible simple sugars are readily available around in the rhizosphere. Root exudates, dead plant debris, simple sugars, and complex polysaccharides are abundant in this region.
So how can we maintain an aerobic soil when the weather conditions are so wet? The answer is that we can’t. As with many things in life the secret is preparation. We undertake renovations at the end of the summer because we have good growing conditions – soil temperatures in excess of 10 °C and consistent moisture, these renovations stimulate the grass plant to grow into the spaces that we’ve created. We’re engineering an environment, around the rhizosphere, that is suited to the aerobic species that we want. Despite this soils that have been waterlogged for long periods of time, because of this wet autumn, will need some additional support to kick-start the development of an aerobic suite of bacteria.
Do no harm
The first principles of first aid are that we do no harm, and that principle also applies to environmental management regimes. If we take machinery over waterlogged soils we are likely to create problems as we compact and damage the soil structure. Ideally whilst the drains are still running, we need to stay off the surface. When the drains stop running the soil is said to be at field capacity. Only when drains have stopped running, and you can start to hear the soil pores opening, should we think about putting any machinery over the surface – and even then we need to be cautious: spread the weight with turf tyres at low pressure.
Aeration should be our next priority, depending on the kit we have and the ability for us to make a mess of the surface we can consider a range of devices available: verti-draining, solid tining, air injection, earthquaking and slitting are all forms that use different mechanisms to reincorporate oxygen back into the rootzone. Different root zones drain at varying rates because of the distribution of the different sand, silt and clay particle sizes. They will determine how quickly the moisture can flow away or how intractable the soil is.
Once we’ve aerated, and if temperatures are sufficiently mild, we can then think about trying to build up the levels of beneficial organisms by supplying them with some readily available nutrients e.g. carbon sources such as SeaAction liquid seaweed or BioMass Sugar. The movement and development of microorganisms will help restructure a soil and maintain oxygen within the rootzone. This benefits the plant which can then obtain nutrients through the activity of bacteria, facilitating good plant health and recovery ability.
We will all have suffered some losses over what is turning into an exceptionally wet autumn for many green keepers and groundstaff. Hopefully a dry Christmas will help us get some much needed air into our surfaces and whilst we’re eating the occasional mince pie we can console ourselves that we’ll be turning that corner in the calendar this month and from the 21st we’ll be starting the steady journey towards what we all hope will be an inspirational new decade.
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.