Bowling Green FAQ 8: Why is the green fairly slow?

This might be the commonest question asked by bowlers. This does depend on what is meant by slow as this can be quite subjective. The time taken for a bowl to travel from delivery release to reaching the area with the jack should ideally be 10-11 seconds as a minimum and would be seen as on the slow side; whilst 12-13 seconds would be a good speed and 14-16 on the good to fast side and would be suitable for some but also too fast for others as well.

A thatch, soft, green, particularly when moist or wet will allow the bowl to sink into the surface slightly. During travel the bowl would therefore be slightly depressed into the surface and this would increase the resistance offered to a forward moving ball, slowing it down quite a bit. To partly overcome this a bowler will need to give greater initial force to negate some of this resistance. The bowl will travel in a more direct line if it is to reach the jack as draw will often be poor on soft slow greens. Trying to use the bias on a slow green will typically see the bowl swing out but not back in adequately as the steady speed needed to get the most from a draw would not be possible, or very challenging at best to achieve.

Think of a slow green as one where it means a shorter distance which the bowl travels and is more in a straight line if it is to reach the jack. By contrast, on a fast or faster (which will have a firmer surface) green the bowl can follow an arc as it moves out then curves back in, producing a longer distance over which it has travelled.

The classic short-term solution for a slow green is to lower the height of cut, however, this is a recipe for long-term problems and should only be carried out temporarily, with caution, and returned to a height which is more conducive for a durable sward and with the aim to also encourage the finer grasses of fescues and browntop bent.

Effective actions will need to be carried out to address the underlying cause of the slowness. Typical work that might be considered includes:
• Double hollow-tining at during early September after main tournaments have finished but the season is still going on, overseeding and applying a heavy loamy sandy top-dressing and working it in thoroughly.
• Regular verticutting on a weekly basis, unless drought conditions arise.
• Regular scarification, but not deep, during the remainder of the playing season, unless drought conditions arise.
• Increase mowing frequency as this will be better than reducing the height of cut, double cutting on main competition days.
• Review the fertiliser programme. Focus on fertilisers which produce an acidifying effect. Do not apply unnecessary applications of phosphorus and aim for no Nitrogen fertiliser after August.
• Avoid high rates of fertiliser applications, which will only encourage excessive leafy growth which will contribute to slowing a bowl, and result in the need to increase mowing frequency.
• Test the pH of the irrigation water to see if this might be encouraging annual meadow grass (which it will be doing if more of an alkaline, less acidic water) at the expense of fescue/bent.
• Avoid frequent watering and overwatering.
• Aerate to encourage deeper rooting and exploration of the rootzone by the roots. This will reduce irrigation frequency.
• Check the frequency and amount of water applied on each occasion. Regular, shallow, light watering will encourage shallow rooting and an increase in thatch.
• Annual meadow grass dominated greens are slower than fescue/bent dominated greens, so aim to reduce the content of this undesirable grass species.
• Rolling a green will temporarily improve green speed but this will gradually build-up problems later on and does not address the cause of a slow green. So, don’t use rolling as a means to speed up a green as a matter of routine, but only for specific manged outcomes, for example, for tournament preparation, or for firming surfaces following winter frost disturbance, or following mechanical disturbance from machinery use.

A very even and smooth surface will produce a consistent roll of the bowl throughout the green, allowing for improved control and weight of delivery. Regular top-dressing is required to smooth out minor blemishes and micro-depressions which will arise over the course of a playing season.