The watering of bowling greens is one of those critical issues in bowling that splits opinion across the game.
Some purists would see no artificial watering of greens regardless of how dry the weather gets. Some are in favour to different degrees; some would argue that the green should only be watered enough to keep it alive, while others demand that the green be watered heavily and often to keep it green.
For me the critical issue is as always performance.
We can argue about the right way to water or not water greens until the cows come home, but green performance is the only measure we should really be worrying about and that means we need to deal with individual greens on an individual basis.
Some greens, mainly those that haven’t been subjected to years of sandy top-dressings dry out evenly across the surface. As the weather gets drier, these greens get faster and smoother and everyone is happy. However, there is a point of no return for these greens also and a complete drought will see them go dormant and lose a lot of grass cover; causing poor performance in the later part of the season and great difficulty in surviving a harsh winter and/or in producing a surface early next season.
Greens that have suffered decades of inappropriate maintenance (the majority), have a high percentage of sand in the rootzone from top-dressing and dry out un-evenly and un-predictably, causing problems with surface levels, green speed and surface consistency. Invariably, these greens suffer from Localised Dry Patch, which prevents them from re-wetting evenly.
Leaving these greens to dry out completely is a recipe for disaster as they will not perform for the entire season after this. They will re-wet very unevenly and the surface levels, speed and consistency will suffer enormously.
Most automatic bowling green irrigation systems are inefficient, producing un-even coverage and don’t have sufficient storage or design capacity to water a bowling green effectively; it is vitally important to keep this in mind and supplement your system with hand watering when required.
On greens affected by Localised Dry Patch there should be an allowance for applying wetting agents and for keeping the surface open throughout the season by means of the sarrel roller.
Getting irrigation right is not difficult, but correct irrigation practice does look a lot different from the common approach I see at many clubs.
Irrigation practice should be guided by a thorough understanding of water balance as described in Performance Bowling Greens and an understanding of the drawbacks of modern irrigation systems; in particular the application time required to replace a millimetre of water to the green.