Natural grass tennis courts will be coming to the end of their playing season, with the groundstaff organising and preparing for the end of season renovation works, which often starts mid September, with the aim of completing all renovation works before the end of the month.
It is important that you carefully evaluate the needs of your courts; the work required will be determined by the condition of the courts with regard to wear (bare areas), weed infestation, levels of thatch content, nutrient status and overall surface levels.
A soil analysis will help determine a number of facts to help you decide on the appropriate treatments and choice of materials required for your end of season renovations.
By taking a soil sample you can also identify the amount of thatch present. This will help you decide on the level of scarification required. One of the biggest problems during renovations is the fact that many clubs do not remove enough thatch from their swards. This is often due to either not enough passes with the scarifier at the correct depths or using a machine that is not robust enough or engineered to cope with the work required.
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 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 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 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.
It is important to work with the weather conditions, particularly when applying and spreading top dressing materials; the surface needs to be dry.
However, there needs to be adequate moisture in the soil profile when applying granular fertilizer products so that they become activated and soluble, enabling then 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 scarifies 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 clubs 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 sward, preparing surfaces for renovation. Lower cutting height to about 3-4mm to clean and prepare courts.
Scarification - 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 courts 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 100-200mm.
Topdressing 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.
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 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.
Brus to incorporate dressings and to help the grass stand back up. Brush in with a lute or drag brush/mat to restore levels.
It is essential to keep the sward watered after renovations to ensure your seed germinates.