The recent warm and wet conditions will also have stimulated some rapid growth and vigour, which will have increased the amount of thatch being accumulated in the green. Extensive grass growth usually results in a lot of thatch. Thatch is a widely used term, describing a layer of organic material in or near the top of the playing surface. Thatch is the build up of grass clippings, dead leaves and plant material, including the root mass. In fact, having some thatch can be beneficial, however it often becomes a greater problem when out of control which, in bowling green terms, results in slow soft greens, bringing with it many other agronomic problems.
A simple test of thatch is the 'finger test'. If your thatch is one finger's width deep, you are okay; two fingers or more and you have a problem! The benefits of having about 6-8mm of thatch are it acts a sun screen, retains moisture, provides food for organisms to feed on and provides sources of humus.
The type of organic material that isn't beneficial though is the detritus, or the woodier forms of the plant. Although not appearing particularly woody to us, the leaves, stems and roots contain lignins and these do not readily break down in decomposition. Thatch on or near the surface causes reduced air and water exchange in the soil; it retains excessive moisture, encouraging the roots to stay near the surface and will lower soil pH. If the organic material isn't managed properly during the season, and not removed properly at the end of the season, then subsequent top dressings cover the organic material and cause a buried thatch layer.
It is important we control this layer and remove any unwanted thatch by mechanical means, usually done during both autumn and spring renovations, however the optimum time is in the autumn.
With this season's match play now coming to an end, many clubs should be organising and sourcing materials and products for their end of season renovations. Most clubs will be looking to begin their renovations towards the end of September, making good use of the warm soil temperatures to initiate seed germination.
Before you arrange any work, it is best to examine the condition of your turf and soil profiles. Do not be afraid to take a couple of core samples from your green, allowing you the opportunity to see what lies below the surface. On examination, you should be able to see how much thatch you have and the condition of the soil.
September is also be an ideal time to undertake any major or minor repair jobs on the green, such as improvements to drainage systems or addressing levels or redefining crown heights on crown greens.
Key Tasks for September
Unfortunately, one of the deciding factors that often reduces the effectiveness of these planned works is the amount of money (budget ) the club has available. It can cost anything between £1200-£1500 for a contractor to come in and do all the work.
Savings can be made if the club undertake the work themselves, however, the effectiveness of the work carried out will be determined by the equipment they have at their disposal.
Savings can also be made if clubs buy materials in bulk (several clubs group buying).
The best way to balance the health of the grass plant and to achieve good green speed is to promote and carry out effective cultural practices to maintain surface playability
The following activities are generally implemented during autumn renovations and usually carried out in the following order, when conditions allow. The sequence of operations and their intensity will vary from green to green according to the condition at the end of the season.
Mowing the sward, preparing surfaces for renovation: lower cutting height to about 3-4mm to clean and prepare green for renovation operations. The mower can then be used to clean up the green after scarifying has been completed.
Scarification, removal of unwanted debris: collect and disposal of arisings. 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.
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 150-200mm.
Topdressing restores levels and improves surface drainage. Ensure you use compatible topdressing 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. Brush 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 to 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 NPK 5:5:15 to help the sward through the autumn period.
Watering/Irrigation is essential after renovations to ensure your seed germinates.
With the season finished and the green closed down for the winter, mowing will only be required to maintain a winter height of cut at 8-12mm. Some clubs are now using rotary mowers to keep the greens tidy through the winter months. This methods does two jobs in one, it keeps the grass topped and hoovers up any surface debris, such as twigs and leaves.
Brushing/switching of the playing surface keeps the green clean and removes any dew or surface water. Keeping the surface dry will aid resistance to disease.
There are many tests that can be undertaken, but usually the main three tests to consider are: Particle Size Distribution (PSD) this will give you accurate information on the soil type and its particle make up, enabling you to match up with appropriate top dressing materials and ensuring you are able to maintain a consistent hydraulic conductivity (drainage rate) of your soil profile.
Soil pH. It is important to keep the soil at a pH of 5.5-6.5, a suitable level for most grass plants, and a balanced level of organic matter content in the soil profile.
N:P:K: Keeping a balance of N P K nutrients within the soil profile is essential for healthy plant growth.
Red thread , Fusarioum and Fairy rings can be a common sight on bowling greens at this time of the year. Click on the following links to view in depth articles about diseases :-
Keep an eye on fungal disease attack and use approved fungicides to treat infected areas.
Regular brushing and sweeping are important tasks to keep the surface clean, open and dry. A dry surface will aid resistance to disease.
Keep machines overhauled and clean. Keep an eye on your material stocks (seed, topdressing, petrol, oil), remembering to replenish as required.
Ensure you look after your equipment and store safe and secure, it is a good idea to get into a habit of washing down and and cleaning after use.
Delegates attending the Bowling Green course and using the accompanying manual will be able to develop their own skills, working knowledge and expertise, by understanding the method of instruction and the maintenance principle it sets out.
Our next course is taking place on Friday, 25 September at Rayleigh Bowls Club, Essex. More details of this course.
Included in the Course Manual, there are working diaries showing the range of tasks needed to be accomplished each month. The Course Manual is available for purchase separately.
In addition, we are able to arrange courses to be delivered on site to groups of 6 – 10 people. Email Chris Johnson for information.
