The recent cold weather has done nothing to encourage any real grass growth. We will not see any significant growth until temperatures rise consistently above 12 degrees C. Also, fertilisers will not begin to work efficiently until temperatures rise and there is enough moisture in the soil.
Pre season rolling should have begun using your mowers. Clay soils need a certain amount of moisture for effective rolling to be achieved. Also, clay soils take longer to warm up and, therefore, the grass will be slower to develop.
The recent windy weather may have dried out many courts. It will be important to ensure your irrigation systems are up and working. You may need to irrigate to aid growth and uptake of fertiliser products. Under normal circumstances you will now be looking to apply a spring fertiliser to initiate some healthy growth.
Fertiliser treatment and turf tonic can be continued in accordance with your annual programme. If you haven't got a fertiliser programme, have your soil tested; try an independent soil analysis company for an impartial set of results. Apply a spring fertiliser when conditions allow. Fertilisers can be applied in liquid or granular forms. Most grounds staff will be applying something like a 12/0/9 or 9/7/7 to get the grass moving during April then, towards the end of April or early May, applying a slow release fertiliser to see you through to June/July.
The choice of material and how well it works can be dependant on many factors, soil type, weather, with moisture and soil temperature being the catalyst for growth. The performance of slow release fertilisers can be influenced by the weather, often producing a flush of growth when you least expect it. Some grounds managers may use straight compound granular or liquid fertilisers which activate when in contact with moist soil conditions, effectively stimulating grass growth within days.
It is essential to carryout an affective rolling programme in April. Continue to roll the courts, firstly across the line of play, followed by rolling down the length of play. Timing of this operation is vitally important. Trying to roll when soil conditions are wet or too dry will not achieve the desired effect. Ideal rolling conditions would suggest the soil be in a state of plasticity, or "plasticine".
Gradually build up roller weight by moving onto the next size of cylinder mower and so on. Consolidation is your aim and the quality of rolling will show when you produce your early season courts. If the roller is causing damage to the turf surface (ridging) stop rolling and wait for drier conditions.
Renovation will involve a number of tasks - scarification, aeration, overseeding, fertilising and topdressing: Click here to see Spring Renovation article.
Generally, the level of renovation will be dependant on budgets, whatever the club/facility can afford. Ideally, the green will be multi cored/aerated to relieve compaction, followed by overseeding (applying seed at rate of 17-35gm per sq m). Pre seeding fertiliser may be applied to help the germination. On completion of these tasks, top dressing materials are applied using selected rootzone or sand materials. It is best to evaluate your soil type, getting an analysis of the soil, enabling a good match of materials for your site.
Tennis court maintenance
Most of your aeration operations should have been completed during the winter period; generally, we do not aerate clay soil profiles after January, as we do not want to encourage cracking of the clay surfaces. However, if there is a need to help remove surface water from the courts we can utilise the sarrel roller which lightly aerates the top 25-30mm, allowing any surface water to drain down deeper into the soil profile.
Prior to mowing, the surface should be thoroughly brushed, every time. Continue to brush courts daily to remove moisture from the grass surface, stopping the spread of disease and facilitating an improved quality of cut on the dry grass.
The mowing height on the courts should be lowered to around 8-10mm for the playing season, 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 season. Mowing frequency will be dependant on a number of factors - grass growth, sward type, level or standard of facility, resources (staff & machinery), but generally it may vary from three days a week to weekly frequencies.
Light scarification or verticutting can be carried out at fortnightly intervals pre-season. Removing horizontally growing grasses and surface organic matter are always beneficial for the onset of court preparation which, together with brushing, will improve the quality of cut.
To ensure accurate lines, consult the Lawn Tennis Association's rules and regulations and use approved line marking materials, set out base lines and side lines using the 3,4,5 method.
Worm treatments can be carried out if needed, but please remember to ask yourself why are worms present. Ph level, organic matter and your cultural practices on the square need to be assessed.
Keep and eye on fungal disease attack, and use approved fungicides to treat infected areas.
It is important to remove any weeds from the playing surface, as they can affect ball bounce and performance of the court. Weeds can be removed mechanically by hand, or controlled by the application of chemicals, usually a broadleaf selective weed killer. Best results are achieved when the soil has warmed up and the grass is actively growing.
Seeding sparse or bare areas can be continued. Any rise in soil or air temperatures will help germination. Use germination sheets to aid this process but remove the sheets regularly to check for diseases. Remember that without good seed to soil contact the operation is useless. Ensure you use new seed as old material may not give you the required germination rates.
Artificial Tennis Courts
Artificial grass systems:
Keep surface clean, regular sweeping and brushing. Remove any algae and moss from surface. Sand filled systems require regular brushing to maintain manufacturer's recommendations on sand levels and pile heights.
American Fast Dry courts:
Keep surfaces clean, rolling to consolidate surface, levelling and brushing of fast dry materials, brushing to clean lines.
Keep surfaces clean, regular sweeping and brushing. Repair any hollows or damaged areas. Repaint lines.