Introduction
With the season typically commencing towards the end of April, a pre-season preparation programme will begin towards the end of March to early April.
In principle, the later the start of the preparation programme the better. This is to allow the weather to warm the soil as much as possible, encouraging more vigorous grass growth which in turn will be able to produce an improved response to the work being carried out.
However, a compromise has to be achieved because starting the preparation programme too near to the starting day may leave the surface not up to the standard required. The main concern is usually to do with how well any top-dressing will have worked into the surface of the green.
A typical pre-season preparation programme will consist of the following tasks (let us say that it starts the first week in April and the opening day is a full three weeks away):
Mowing
A gradual reduction in the height of cut will be achieved, going from the winter height, of say 11mm (7/16") to an initial start day height of 6.5mm ( ¼ "). It is usually a good idea to start the playing season at this height (or maybe 6mm (15/64"), as it allows the grass a little leeway if there is an early cold or dry spell, which would retard growth and consider also that the grass will not be making optimum growth quite yet as well. A problem could therefore arise if the height of cut commenced at 5mm (3/16").
The down side of starting at 6 - 6.5mm is that the green will be slightly slower to start with, but not significantly. Patience is the order of the day and bowlers will be rewarded soon enough.
| 3 weeks to go | 2 weeks to go | 1 week to go | Start day |
| 11m (7/16") | 9.5mm (3/8") | 8mm (5/16") | 6.5mm (1/4") or 6mm (15/64") |
| This is a sensible sequence, as a gradual reduction in the mowing height of just some 1.5mm (1/16") takes place each week. | |||
Aeration
A suitable amount of aeration work needs to be undertaken to allow for the exchange of air between the rootzone and the surface, especially now that the green will be growing actively.
The use of slit tines will generally cease after the start of April due to the likelihood of the slits opening up on the surface in dry weather, which is practically inevitable sometime in May and solid tining will take over.
The drying soil will also reduce the chance of much sideways soil compaction and smearing from the solid tines penetrating into the soil profile and this will also not have the disadvantage of the tine hole gaping in dry weather, which is a problem with slit tining.
Sarel spike (with 25-50mm 'tines') rolling will also start to take place. This will not only ensure that the surface layer is well covered with tiny holes, but will also act to lightly firm the surface of the green.
Scarification etc.
This will help to remove debris which may have built up since last year and will also be part of the control programme for any undesirable thatch which may be present.
Only a light form of scarification, say to 2 or 3mm depth, should take place at the present time because the grass will not be growing all that vigorously. Thinning of the sward at this time of year by over enthusiastic use of the scarifier is definitely not a good idea.
If the operation appears to be causing damage to the green, stop and adjust the scarifier - don't just carry on.
Verticutting and vertigrooming can also start to take place, encouraging more upright grass growth.
Do not scarify or verticut for about a week after fertilising and several weeks after over-seeding or top-dressing, as this can remove material and in particular dislodge newly establishing grass seedlings. Vertigroom with care during this period if needed.
Wetting Agent
If drying out of the bowling green, or part of the green, has been a recent or ongoing problem then the application of a wetting agent may be considered.
Care may need to be taken to ensure no harm is done to seed germination or seedling establishment and it may be necessary to apply any wetting agent in March to allow for adequate chemical dispersion within the soil profile.
The underlying cause of the drying out should be investigated. A good starting point would be by looking at inadequate root penetration into the soil profile which may have been encouraged by insufficient aeration over a period of time, amongst other things.
Dragbrushing
This should be carried out with caution following the application of fertiliser, grass seed or the incorporation of top-dressing.
Fertiliser or top-dressing may stick to the dragbrush bristles if wet. If the surface is dry, however, the dragbrush can help to further incorporate the top-dressing into the surface layer.
Newly germinated grasses can easily be dislodged by the bristles of a dragbrush, so it is a good idea to avoid this operation for a short time until the grass seedlings have rooted slightly, enabling them to remain in place when the dragbrush is pulled over them.
Other
Other areas to look out for at this time of year will be
- earthworm activity, which can produce a high number of surface casts. These are detrimental to the production of a quality playing surface and will need treating - either culturally or chemically; and
- Fusarium Patch disease, which can be most severe during the damp, cool April mornings; and
- Damping off disease could be a problem for sown grass seed, so keep a careful watch.
Fertiliser
Sometime during March there is typically a relatively warm spell, or 'false spring', which produces a spurt of growth. More often than not there is a return to the colder temperatures after a week or two, suppressing growth again.
Good grass growth doesn't really occur until usually at least the middle of April, with the onset of improved light levels and temperature.
To reduce the chance of artificially forcing the grass into producing soft susceptible growth in early to mid-March by giving the main spring fertiliser at this time, it is good practice to apply a turf tonic instead.
This typically consists of just a small amount of nitrogen and usually some iron. A common turf tonic is a mixture of
- 6-8 grams of ammonium sulphate (20.5% N), and
- 4-6 grams of sulphate of iron,
The mixture is therefore applied at between 10 and 14 g/m² depending upon the rates chosen.
The actual quantity of nitrogen applied will be between 1.2 and 1.6 g/m² : ( 20.5% N of 6 grams = 1.2g; whilst 20.5% N of 8 grams = 1.6g).
The mixture can either be bulked up with a fine sand to aid distribution, or dissolved in slightly warm water and applied as a liquid tonic.
This tonic provides a small, but not excessive, boost to the plant and is an ideal infiller before the main spring fertiliser in April.
The precise fertiliser analysis for the main spring application will depend upon a number of factors, in particular the existing condition and composition of the sward and rootzone.
There is a wide range of fertilisers available and several will invariably suit each specific situation.
A typical spring fertiliser might consist of the following:
- 14:3:7, where grass seed is being oversown and/or the rootzone is very free draining; or
- 8:0:0, where sward coverage and root development are good; or
- 12:0:9, where sward coverage and root development are good, but the rootzone is very free draining;
There is a whole range of permutations for including or excluding a particular nutrient as well as the source of that nutrient, such as the level of acidity produced or how long the material takes to breakdown to become available to the plant.
After many years of use as well as research, ammonium sulphate has been found to be the most suitable source of nitrogen for fescue / bent turf.
However, with a wide range of construction techniques, greater demands on sports facilities as well as changing climate and weather patterns, it is wise to consider each situation on its own merit and determine which fertiliser source, or range of sources, is most suited to a particular situation.
It is a good idea to combine a soil nutrient analysis test, which is sometimes provided free by some fertiliser manufacturers / suppliers, with a detailed and accurate assessment of the sward surface and rootzone.
When this information is combined with climate data for the area, as well as anticipated usage patterns, then an informed decision can be made, not only for the fertiliser required, but also for the maintenance programme as a whole.
This type of information can save money in both the short and long term and can prevent, or at least reduce, the chance of costly mistakes occurring.
Applying
- the wrong type of fertiliser,
- at the wrong time,
- at an unsuitable rate, and
- in the wrong conditions,
can have a significantly detrimental affect on the quality of a bowling green.
The amount of fertiliser will depend upon the percentage content of nitrogen in the material and the application rate.
Example:
- A fertiliser containing 14% N and applied at 34 g/m² supplies 4.8 g/N/m², (2 x 25kg bags per green);
- whilst a fertiliser containing 8% N and applied at 50 g/m² supplies 4.0 g/N/m², (3 x 25 kg bags per green).
Ensure any fertiliser which is applied is adequately watered in to prevent scorching the grass leaves. Also make sure the fertiliser is applied when the grass is dry, otherwise the material can stick to the leaves causing localised leaf scorch.
Overseeding
Whether improving the sward density or assisting in changing the composition of the sward by trying to reduce the annual meadow grass content, an overseeding in the spring can be beneficial in the overall search for quality playing surfaces.
The main grass species oversown onto a bowling green are:
- Chewing's Fescue;
- Slender Creeping Red Fescue; and
- Browntop Bent.
Other species sometimes considered, include Creeping Bent and Velvet Bent.
The proportions of the species within any mixture will vary according to circumstances, but a useful starting point will be:
- 40% Chewing's Fescue;
- 40% Slender Creeping Red Fescue;
- 20% Browntop Bent.
An application rate of 17 g/m² (that is 1 x 25kg bag per green) is normally adequate. If, however, sward density is relatively poor and annual meadow grass is a problem, then 34 g/m² may be of benefit.
It is essential that suitable preparation work is undertaken before overseeding, otherwise the actual amount of seed which becomes established will be close to nil: This will be a waste of time, money and effort.
Aeration, scarification, possible verticutting, fertiliser application and a light top-dressing will greatly improve the amount of seed which will germinate and establish successfully.
Make sure that the irrigation system is functioning properly as water may need to be applied to aid germination and establishment.
Do not smother the seed by excessive top-dressing and keep air flowing freely over the bowling green. This may mean ensuring dew is removed as early in the morning as possible and any dense perimeter hedging or other vegetation is trimmed and pruned to improve not only air flow but also light levels.
Top-dressing
A light application of a suitable top-dressing material is usually beneficial in April.
This helps to
- even out any minor depressions which may have developed over the winter,
- smooth over any disease scars,
- bind in further any previously turfed area,
- protect newly sown grass seed, and
- provides the basis of an even surface following any minor disturbance from the mechanical preparation work during April, e.g. aeration, scarification etc.
Do not apply too much top-dressing so that the grass is smothered, as this will only encourage the grass to turn yellow and possibly die, produce ideal conditions for disease attack and provide conditions for weeds and weed grasses to colonise into.
It is essential that the bowling green is properly prepared before any top-dressing is given, as this prevents the material from just sitting on any thatch or organic layer which may be present. Over time, continued application without proper preparation would lead to root breaks and shallow rooting of grasses. This will favour annual meadow grass over the more desirable grasses.
Top-dressing should be applied in a dry condition and onto a dry surface. This will work in amongst the base of the plant very quickly and within two weeks from application there should effectively be no visible trace of the top-dressing on the surface.
A typical spring application rate is 2 - 3 tonnes per green. This works out at about 1.4 - 2 kg/m², which actually equates to a depth of top-dressing of around 1mm over the whole green.