Bowling Green Maintenance: 11b. Mowing - Seasonal activity

A bowling green in early spring, prior to the start of the playing season, is in a challenging situation due to the likely variable weather conditions which seem to be occurring each year on a more frequent and regular basis.

Caution should be applied in trying to lower the height of cut too early. Cold spells, early drought, unseasonal hot spells, excessive rainfall, as well as late frosts or snowfall are all distinct probabilities. These can all have a significantly negative impact on grass growth and development. It is wise to provide the grass plant with an added insurance policy of keeping a small amount of extra leaf on during this period, typically 1mm-3mm, until weather conditions in that period of the year stabilise and are more certain to progress into a more consistent good grass growing weather.

If a green is cut during the early pre-season preparation stage, say mid-March, at a height of cut of 12mm and if, for example, there are then still 5 weeks before the first game of the season (although the start of a playing season at a club will vary) then a very gradual reduction in cutting height can easily take place. If the weather is suitable and the club has decided on an opening height of cut of 6mm, then the following approach might be taken to achieve this without undue stress on the grass plant:

• Mid-March (3rd Week): Cut height is 12mm, with 2 cuts this week; (Sat; Weds).

• March Week 4: Cut height is 10mm, with 2 cuts this week; (Sat; Weds).

• April Week 1: Cut height is 9mm, with 3 cuts this week; (Sat; Tues; Fri).

• April Week 2: Cut height is 8mm, with 3 cuts this week (Sat; Tues; Fri).

• April Week 3: Cut height is 7mm, with 2 cuts (Mon; Weds) and then a third and fourth cut (i.e. a double cut) at 6mm (Fri).

• April start of Week 4: day 1: green to be with an opening cut height of 6mm (Saturday morning). If the season starts earlier at a club then start at one of the higher heights given earlier and follow a gradual reduction in cutting height and don’t be in a rush to reduce the height of cut to 5mm, or so.

• The following might then occur for May: Week 1 - 5.5mm; Week 2 onwards - 5mm.

During the playing season the green will be mown in a diagonal fashion, corner-to-corner. The historical reason for this was that mowers could create a track which could influence the run of a bowl as well as act as a guide to help bowlers.

Modern mowing machinery has improved significantly since the 1950s and 1960s and now the only reason for mowing diagonally is that of reducing the potential aid to bowlers in delivering a bowl by using the otherwise up and down stripes as a guide. Outside of competition, or similar days, there is a good argument to mow in the direction of play rather than diagonally. This will also help to increase different mowing directions and reduce the chance of a ‘nap’ developing and will also increase, or maintain an already good, sward density. In addition, varying the location of turning on the green at the ends with the mower can help to reduce the stress put on the grass plant by the mower due to the action of turning of the rear roller.

Mowing during September, especially after the finish of any major tournaments – the last of which might actually be at the end of August – should start to see the height of cut raised gradually. Players will be starting to ‘wind-down’ regards the grass playing season and getting ready for the transition to the indoor scene.

Whilst there is typically a flush of growth during the early to middle of September, this is easily controlled by regular mowing. The grass plant will be wanting to produce food reserves to be stored in roots and rhizomes ready for the overwintering period and for the start of the following spring. Raising the height of cut helps to maximise, within practical limits, the food which can be manufactured in the green grass leaves by photosynthesis. Waiting too long until October to raise the height of cut will significantly reduce a natural process of improving the long-term health and resilience of a plant.

Consider height of cut changes from 5mm, to 6mm, to 7mm and even to 8mm during September. If an early renovation was carried out, then the top-dressing would typically cover about 1mm-2mm of the base of the sward once it has been well worked in, so even an 8mm cut prior to top-dressing would not be especially short.

Frequent mowing, at least on three occasions per week during the main growing season, is important to maintain a compact sward. Mowing on four occasions might be considered a good balance when compared with daily mowing, which is probably unnecessary in many cases and puts considerable stress on the grass plant. A green which is cut on four occasions per week might follow a routine of mowing on Monday, Wednesday, Friday and Saturday. More frequent mowing will be aimed at the more premium level of clubs and greens, which will cost more to maintain as well.

Regularity of mowing is very important if a good playing surface is to be produced. Irregular mowing frequency during the playing season will lead to a more stressed sward which will become less dense, with reduced rooting, an inconsistent draw on the bowl and a slower and less true surface. Keeping the green cut at regular intervals, without removing too much leaf growth per cut is an essential ingredient in the production of a good green.

Ideally, mowing the green will take place when the grass and surface are dry, along with no surface casts from earthworm activity. Switching or dragbrushing a green will help to dry it when dew is present and to disperse worm casts prior to mowing. Cutting blade technology and blade maintenance equipment continues to improve, and whilst a good cut can still be achieved in wet conditions, the best and most consistent cuts will be produced on a dry surface.

Backlap a mower on a routine basis, possibly weekly to keep the bottom blade and cylinder sharp. The required frequency will depend on the amount of use from the mower and if there is any sandy material on the sward surface, such as particles brought to the surface by earthworm casting. If a blade is damaged, or in need of annual refurbishment then a regrind of the cylinder and bottom blade to recreate an initial sharp edge can be carried out – this can then be maintained by regular backlapping during the playing season.

Grass clippings will typically be boxed off and removed on most occasions, although during hot, dry summer weather the occasional letting of clippings fly would not be detrimental to the sward and can aid protect the basal crown of the plant from intense heat.