Chapter 1 Grass Tennis Court Maintenance: An Introduction

Grass TennisCourtMaintenance© The Institute of Groundsmanship 2003

Contents PageChapter 1 Grass Tennis Court Maintenance: An Introduction 1Chapter 2 Pre-Season Maintenance 4Chapter 3 Playing Season Maintenance 7Chapter 4 End of Season Maintenance 10Chapter 5 Maintenance Calendar 14Chapter 6 Cost of Materials 17Disclaimer: All information is provided in good faith and is for general guidance only. No liability can beaccepted for any loss or damage as a result of any information contained herein.© The Institute of Groundsmanship 2003

Chapter 1Grass Tennis Court Maintenance: An IntroductionIntroductionTennis is played on both grass and artificial surfaces.The size of a court is 23.77m length x either 10.97m width for a doubles court or 8.23m width for asingles court.A minimum run back distance of 5.5m should be allowed behind the baseline, whilst there should be aminimum distance of 3m between the court and any perimeter fencing.The playing season on grass courts is generally from the end of April or early May to early September.QualityA tennis court should ideally be• even and smooth throughout, with no undulations or depressions;• well firmed so as to provide a consistent ball bounce and pace;• covered with a uniform dense sward of desirable grasses that have good root density and depth;• weed free to ensure no adverse effect on ball rebound.To ensure that a grass tennis court is maintained correctly, not only during the playing season butthroughout the whole of the year, a number of individual performance standards are likely to be set. Thecombination of these standards determines the overall quality of the court.© The Institute of Groundsmanship 2003 1

Diagram to Illustrate Quality and Individual Standards© The Institute of Groundsmanship 2003 2

The setting of these performance standards provides a means of objectively assessing the quality of thetennis court.Most users wish to have a top class tennis court, however, the true cost in materials, machinery andespecially the skills of a qualified and experienced groundsman do not come cheap. Realistically the aimis for a tennis court that plays well, is safe and is managed in a cost-effective manner.The actual maintenance cost for a tennis court will depend on a number of variables, in particular what isactually included within the so called true cost as some costs are hidden within other charges, especiallywhen comparing local authority costs. A like for like comparison can be notoriously difficult to achieve.© The Institute of Groundsmanship 2003 3

Chapter 2Pre-Season MaintenanceIntroductionThe work carried out during this period will cover January to April.Adequate pre-season work is essential if a well-prepared court is to be presented for play during thesummer months.When soil conditions are wet during this period it is usually beneficial to keep off the court as much aspossible. This will help to reduce the chance of soil smearing and compaction which the relatively heavytennis court soils can be prone to.MowingGradually reduce the height of cut from the winter height of 12-15mm to the start of the season height ofabout 6-8mm.Ideally keep the grass topped so that no more than about 3mm is removed at any one time. Therefore ifthe grass reaches 18mm in height, it will be topped at 15mm. (The exact height will depend upon whetherthe court is mostly perennial ryegrass or a fescue/bent sward).It is important to reduce the height slowly over the whole of this period otherwise a rapid reduction canlead to a drastic thinning of the sward. This thinning will become very evident if a late frost, cold wetspells or cold winds occur.If at all possible try and start the season with as much leaf height as practical, i.e. 8mm or so.Always box off the clippings to reduce the chance of disease attacks and earthworm activity.A typical sequence of cutting height reductions might be as follows:ScarificationDuring April a light to medium scarification might be carried out to remove surface thatch. This operationshould only be carried out when the weather is mild and the grass is growing relatively strongly.© The Institute of Groundsmanship 2003 4

DragbrushingCarry this operation out on a regular basis to keep the grass upright and to help keep adequate air flowaround the grass blades. Earthworm casts, if present, will be dispersed on a regular basis and this will helpto prevent the grass from becoming smothered. A consequence of leaving undisturbed earthworm casts onthe court is that not only can the underlying grass die out but weeds, especially annual meadow grass, willbe able to invade the weakened areas.Fertiliser ApplicationA light application of a fertiliser during the middle of March may be considered. A typical applicationmight provide 1 g/N/m², in a liquid form, by applying 5 g/m² of sulphate of ammonia. A small of amountof iron within the fertiliser may also be considered. The precise make up of the fertiliser, which iseffectively a tonic, will also depend on the species present within the tennis court as care will need to betaken in applying acidic fertilisers if the sward is predominantly perennial ryegrass.Adequate nutrients will need to be applied throughout the whole of the growing season to ensure a hardwearing sward is maintained. A range of fertilisers is suitable for use on a tennis court and the followingtypical nutrient requirements could be used as a starting point: (Reference, STRI 'Fertilisers for Turf,1996, p.36)• Nitrogen: 8 -12 g/m²• Phosphate: 2 - 4 g/m²• Potash: 4 - 10 g/m²The quantity of phosphate and potash will depend upon soil analyses and sward assessments, however, anapplication of phosphate can be beneficial at the end of the season when the court is being renovated.An April fertiliser might consist of the following:14:0:7 @ 25g/m², providing 3.5 g/N/m², or12:0:6 @ 25g/m², providing 3 g/N/m², or similar.Chemical ApplicationsThe need to spray pesticides will depend on weather conditions and the condition of the court. Fusariumcan be a problem during moist and relatively warm spring conditions, whilst earthworm activity can be aproblem on heavy soils.Moss can also be a problem during the pre-season period.An initial application of a wetting agent may also be beneficial to assist water penetration when the drierspring and summer periods arrive.© The Institute of Groundsmanship 2003 5

RollingAn initial light rolling will probably commence in March (with a 3-5 cwt light roller).The weight can increase to 10-12 cwt during April, although care needs to be taken not to roll toofrequently, otherwise excessive compaction will be caused.Other WorkAn application of top-dressing is not normally carried out prior to the start of the season, as the material isunlikely to become adequately incorporated into the soil profile before the commencement of the firstmatch.Set and mark out the court ready for the start of play.© The Institute of Groundsmanship 2003 6

Chapter 3Playing Season MaintenanceIntroductionThe results of the spring work should have produced a firm surface that can now provide the foundationfor a good season's play.Maintenance work during May to early September will ensure that the standard of facility provides for aconsistent match of tennis where the errors caused are due to the players and not due to a poor playingsurface. Where there are a number of courts within a facility, it is important that in general each courtshould play fairly consistently when compared with any other of the courts.MowingThe frequency of mowing will depend upon the amount of top growth produced and the standard of pitchrequired. Typically a pitch will be mown three times a week, however, during competition play mowingwill be at least daily, whilst during dry periods this may be reduced to twice a week.The height of cut will generally depend upon the dominant grass species.Perennial ryegrass dominant swards will typically be mown at around 8mm, whilst a fescue / bentdominant sward will be mown at around 6mm height of cut.Tournament play may involve reducing the height of cut to 5mm.Line MarkingMark out the courts on a regular basis, typically after each cut, to ensure the players (and umpire/linejudges where present) can make correct decisions as to whether a ball was in or outside of a line.Scarification/VerticuttingThatch and fibre can be a problem in tennis courts, resulting in a lower bounce and slower courts as someof the energy from a tennis ball is absorbed by the thatch. This is undesirable and should not be allowedto develop.Light scarification on a monthly basis might be carried out on some courts, however, care must be takento ensure the surface is not scored in such a way as to affect play and the presentation of the court.© The Institute of Groundsmanship 2003 7

Verticutting on a fortnightly basis can be undertaken during the growing season to prevent the build up ofthatch. Care will need to be taken to ensure that the grass plant is not put under undue stress when theweather is hot and dry. It is likely that this operation will have to cease temporarily during such periods.GroomingThis operation can be carried out on a regular basis, two or three occasions per week, at the same time asmowing.Grooming may be with a comb attachment or a powered groomer fitted to a cylinder mower.The groomer might typically be set to be 1 - 2 mm below the set height of cut to ensure that the grass isrelatively upright prior to being cut with the mower.Fertiliser ApplicationTo maintain an adequate hard wearing sward during play, a typical May/June fertiliser might be appliedon the following lines:8:0:0 @ 35g/m², providing 2.8 g/N/m²DragbrushingThis should be carried out on a regular, almost daily, basis to ensure the grass is maintained in an uprightgrowing condition and is also kept free of dew at the same time.Switching may be carried out to remove dew when the drag brush is not used.Chemical ApplicationsMay is usually a good time to carry out any herbicide application. Growth is usually good at this time ofyear and this allows for effective control and potential elimination of most weeds.Fusarium patch might be a problem on intensively maintained tennis courts, especially where annualmeadow grass has gained a foothold.Careful observation is required to ensure early signs of a disease attack do not go unnoticed.An additional application of a wetting agent may also be considered. This can be beneficial in promotinginitial infiltration and subsequent movement of water through the soil profile.IrrigationIrrigation will be required when dry periods occur and also maintain an appropriate playing surface.© The Institute of Groundsmanship 2003 8

With the relatively low infiltration rates of tennis courts when compared to sandy soils, there will be aneed to apply the irrigation lightly, yet in sufficient quantity, to allow for a reasonable depth ofpenetration.Shallow watering will encourage shallow rooting in grasses. If this practice is carried out for a continuousperiod of time then it would result in a sward that does not bind the soil as well as deep rooted grass andis more easily worn.Another consequence of shallow watering is that it encourages the development of annual meadow grassand thatch build up.Spiking with a sarel roller may be considered prior to irrigation as this will aid penetration into the soilprofile yet at the same time avoid the sort of surface disturbance that can result from solid or slit tining,especially when the soil is dry.Post-Match RenovationAfter competition matches and when there has been intensive use of a court, then some form ofrenovation work will need to be undertaken. Players may have caused some minor holes or depressionsthat need attending to in addition to any scuffing or thinning of the surface that may have happened.Typically this will take the form of brushing the court and mowing it to produce a clean surface. Thinareas can be sarel spiked, irrigated and occasionally oversown with a small quantity of pre-germinatedgrass seed and a light covering of grass clippings applied over the whole of the renovated area.Minor repairs would take the form of hand forking and working a moist but pliable top-dressing firmlyinto the hole or depression. The groundsmans paint of grass clippings can be lightly sprinkled over therepaired area.Care should be taken if grass clippings are sprinkled over renovated or thin areas as this operation may beinadvertently spreading annual meadow grass seed.Irrigate the whole court to help sward recovery.RollingThe use of a roller, which may vary in weight from 5 - 12 cwt (250 - 600kg), can be employed on anoccasional basis to provide additional firming to a court. This would be particularly appropriate for themore important games and competitions.The amount of rolling and weight of roller can, in practice, vary quite considerably according torequirements. Some courts may have quite a number of hours rolling leading up to a major tournament,whilst others will have very few.Other WorkSwitch courts as required to remove dew, especially where a drag brush has not been planned for use.© The Institute of Groundsmanship 2003 9

Chapter 4End of Season MaintenanceIntroductionThis involves renovating the court to aid recovery from the past season and lay the foundations for thefollowing season in some seven months time.Where there are a number of tennis courts, it is generally a good idea to gradually take them out of playone, or a few, at a time. This allows play to continue for a little longer, which will invariably please theusers. If there are too many courts to work on in a sequence then it could look, from a player'sperspective, as though the groundsman has been over zealous in closing all the courts at the same time.IrrigationIrrigate the court thoroughly, if rain has not done the job already.This will help to aid the renovation process by allowing aeration tines to penetrate to a greater depth thanif the soil had been dry and will allow the scarifier to remove any thatch build-up more efficiently withoutcausing severe surface damage.AerationThe court will usually be well aerated using solid tines. A punch action machine is particularly useful inthis respect. Aim to penetrate to a depth of at least 100mm.If the court suffers from an undesirable level of thatch then the use of hollow-tines may also beconsidered appropriate.ScarificationThe court should be given a thorough scarification to remove any surface thatch layer.The depth of tine penetration will vary according to needs and the condition of the court, however,scarifying to 5-8mm depth can be considered appropriate for the renovation period.Scouring of the surface will also help to produce grooves into which grass seed will be able to settle andestablish, as well as for providing the important 'key' for the top-dressing to bind into the underlying soilprofile.© The Institute of Groundsmanship 2003 10

OverseedingUse an appropriate grass seed mixture. The application rate can vary quite widely depending upon thecondition of the court, i.e. 17-70 g/m².The seed might be a mixture of several perennial ryegrass cultivars along with one or some of thefollowing species:• slender creeping red fescue,• chewings fescue,• browntop bent,• or various other permutations with these species.It really does depend on the requirements of the court.To ensure evenness of application, spread the seed in several directions. In addition, it can sometimes bebeneficial to 'drill' seed into the surface by using a seed-drill machine.Alternatively, the use of a sarel-spiked roller can be used prior to sowing seed.These additional seeding tasks will enhance seed establishment.It is a good idea to give consideration to purchasing a good quality grass seed. Besides being providedwith a good cultivar, the purity of the seed will be excellent and will contain less weed seeds than lesserquality products. A benefit of this is that there can be a reduced need to apply herbicides, save onapplication costs, less chance of annual meadow grass seed being present and can be moreenvironmentally friendly due to the potential reduction in pesticide application.Fertiliser ApplicationAn end of season fertiliser might typically be given during August. It would be low in nitrogen and thelevel of phosphorus and potassium would be determined by the sward composition and soil analysis.A general starting point for a fertiliser might be:14:3:7 @ 25 g/m², providing 3.5 g/N/m², or8:2:6 @ 35 g/m², providing 2.8 g/N/m².The exact composition and analysis will depend upon the requirements of the court, in particular whetherthe sward is mainly perennial ryegrass or fescue/bent.Top-dressingIt is important to ensure that not only is an appropriate material used with the required soil strength for thestandard of pitch, but the material must also be compatible with the existing soil profile.© The Institute of Groundsmanship 2003 11

It is good practice to make sure the top-dressing material is tested beforehand to confirm soil strength andcompatibility. The binding strength of soil, measured using the ASSB method, can be suitably determinedby groundsmen using their own basic equipment.The percentage of clay within a top-dressing for a club level court will typically be within the range 18-20% and will provide a soil strength of some 40kg.Where courts are on a sandy soil and additional binding strength is required then a higher clay content of20-25% might be considered.A typical rate of application for a top-dressing is 1 - 3 kg/m², depending upon the level and intensity ofaeration undertaken.Work the top-dressing into the prepared court by the use of a relatively large trulute (2 to 3 metre width)or an appropriate straight edged implement. Where a large amount of top-dressing has been applied, theneed for strong physical effort may be essential in dragging the implement and top-dressing over thecourt.Other Renovation WorkBase lines can become severely worn and it may be appropriate to turf these areas. The turf used shouldideally have been grown in a turf nursery that has the same soil composition as the tennis court beingturfed.The use of germination sheets can be of benefit, particularly on very thin areas. However, care needs to betaken as fusarium can be encouraged due to the increased humidity and temperature that typically occursbeneath a germination sheet.'Typical' Renovation Programme• Irrigate to 'soften' the soil profile,• Scarify in several (3 or more) directions,• Mow the grass to 6-8mm, removing all clippings,• Aerate by appropriate means - this could be anything from deep solid spiking to at least 100mmdepth, to sarel spiking to about 40mm depth, or even hollow-tining. It is important that the court issuitably moist, but not wet, to allow for good tine penetration when carrying out the aeration work,• Overseed and possibly drill the seed into the surface,• Turf the base lines if required,• Top-dress: Generally this might range from 1.5 to 3 kg/m²; depending upon the type of aerationwork carried out. Work the top-dressing into the sward and soil surface,• Irrigate to ensure adequate germination takes place,© The Institute of Groundsmanship 2003 12

Ideally all this renovation will have been carried out by the middle of September. This should still allowfor adequate germination and establishment before cold soil and air temperatures become unsuitable forgood establishment.Post Renovation WorkFollowing renovation, the court will need to be nurtured from the end of September to December to assistin the development of a compact sward.Typical work will include the following• keeping the grass topped to around 12-15mm, or as desired,• regular drag-brushing,• switching to remove dew,• earthworm control (this may typically be through drag-brushing or chemical control),• moss control,• watching out for disease and controlling as necessary,• aeration (solid and slit/chisel tines), and• removing leaves and twigs.© The Institute of Groundsmanship 2003 13

Chapter 5Maintenance CalendarThe estimated number of occasions for which each task that is planned to be carried out can be presentedin the form of a maintenance calendar.The total number of actual operations will vary according to the prevailing weather conditions, as well asthe geographic location of the tennis court; each factor can influence the length of the growing season andgrass vigour.Maintenance calendars can provide a very useful means for forward planning and the information can beconverted into a staff profile, indicating workload levels, material requirements or budget flow.The 'Months' in the Table are given as 4 or 5 week periods for convenience; this still adds up to 13 weeksper quarter. There is no reason why, for example, the January month is given as 5 weeks, so long as eachquarterly block is made up of one 5 week period and the other two are 4 week periods, thus giving 13weeks for each quarter.It is useful to have April as a 5-week period as it gives some more leeway in planning, although this isprobably arbitrary.Each month could also be the exact number of days in a calendar month. Whichever system works for theuser, then this is the one that should be adopted.© The Institute of Groundsmanship 2003 14

Table shows 'typical' work undertaken on a tennis courtTask \ Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total(No.of weeks per'month')5 4 4 5 4 4 5 4 4 5 4 4 52Mow @ 12 - 15mm 1 1 6 4 2 14Mow @ 12 - 8mm 15 10 25Mow @ 6 - 8mm 12 12 15 12 8 59Aeration: Slit tine 1 2 1 1 1 6Aeration: Solid tine 1 1 1 1 3 1 1 1 10Aeration: 'Sarel'type tineInitial setting out ofa courtDismantle tennisposts and net1 4 4 5 4 4 221 11 1Top-dress 1 1Overseed 1 1Returf base lines 1 1Fertilise 1 1 1 3Turf tonic 1 1Light rolling (3-5cwt)Medium rolling(~10-15 cwt)2 4 1 1 2 1 113 2 2 2 1 10Scarification 2 1 1 1 1 3 9Verticutting 1 2 2 2 2 1 10Vertigroom /Grooming combs4 10 8 8 10 8 4 52© The Institute of Groundsmanship 2003 15

Dragbrushing /Switching10 10 12 15 12 12 15 12 4 10 8 8 128Irrigation 4 8 10 12 10 6 50Repair work duringplay2 2 2 2 8Pesticideapplication:Fungicide: Contact 1 1 1 3Herbicide 1 1Insecticide 1 1 2Moss 1 1Wetting Agent 1 1 2Operations such as systemic fungicide application, sweeping leaves and debris off courts as well as oilingof posts, winding mechanisms and tensioning of nets may also be included within the maintenancecalendar.Other forms of aeration might be considered, such as the use of a Toro Hydroject, whilst hollow-tining(which is not normally carried out on tennis courts as part of routine maintenance) may also be an optionif courts are in a poor condition and major reconstruction work cannot be financed.© The Institute of Groundsmanship 2003 16

Chapter 6Cost of MaterialsThe exact cost of materials will vary depending upon a number of factors such as:• availability;• whether they are specialist or general materials;• the quality of the material, especially top-dressings;• location of the site for delivery from the supplier;• quantity of materials being purchased - discounts for large quantities;• the actual area being included. For example the actual court size equals 261m², whilst if a metre ateach side and two metres behind each base line is counted then this equals 364m². If a minimumrun back of 5.5m is included, as well as 3 metres each side to say a fence line as well, then the areaincreases further still to 590m², and so on.If we take the maintenance calendar as a guide, the following costs might be incurred, for a court of364m²:MaterialQuantity and unit costTotal cost(Spring 2003)Petrol for machines say 20 gallons @ £3.50 per gallon £ 70Top-dressing 3 kg/m² = 1 tonne @ £30 tonne £ 30Grass seed ½ x 25kg bag @ £110 per bag £ 55Fertiliser9.1 kg in April @ £25 bag,12.7 kg in May/June @ £18 bag,Turf tonic (sulphate ofiron)9.1 or 12.7 kg in August @ £28 or £20 per bag(The analysis and form will affect the cost, typicallyranging from £10 - £40 per 25 kg)At 4g/m² in March = 1.5 kg @ £12 per bag£ 27< £ 1© The Institute of Groundsmanship 2003 17

Turf tonic (ammoniumsulphate)At 5g/m² in March = 1.8 kg @ £14 per bag£ 1Turf for worn areas Say 20 m² at £2.50 per m² £ 50Pesticides:(These costs will vary depending upon chemicalingredient and concentration of the chemical)Fungicides £ 37 per application x 3 £ 111Herbicides £ 6 per application x 1 £ 6Insecticides £ 35 per application x 2 £ 70Mosskillers £ 15 per application x 1 £ 15Wetting agents £ 22 per application x 2 £ 44Irrigation water supply If a m³ (220 gallons) of water costs say, 80p;a court requires, say, 25mm per m² of water per week(364m² x 25mm = 9.1 m³).9.1m³ x 80= approximately £7.28 per week. Part of thiswill, however, be supplied by rainfall during the springand summer months. If water had to be applied for, say20 weeks at half the given rate, then this would equal20 weeks x £ 3.64 per week = £ 72.80.£ 73Total £ 553© The Institute of Groundsmanship 2003 18