Bowling Green FAQ 13: How long can we leave hollow-tines open for before top-dressing them?

If hollow-tining is carried out during early spring, then usually top-dressing would be carried out straight away to aim for a completely even surface for the start of the playing season. The main reasons for hollow-tining in the spring might be if the previous end of season work was not completed and the green needs a renovation, in which case micro-tines (5.5-8mm inside diameter) might be considered, or there is significant thatch issue on the green that needs an intensive hollow-tining programme – spring (inside diameter of 12.7mm) and autumn (inside diameter of 12.7-19mm) – to help reduce the problems from excessive thatch.

For the end of season renovation, it can be beneficial to allow the tine holes to stay open for a couple of weeks to improve rootzone to atmosphere air exchange, improving microbiological activity, improve water removal rates following downpours at this time of time, and also to allow compressed edges, where tines penetrated the soil, and existed rootzone to be expand into slightly to reduce soil density.

To avoid green sinkage and unevenness developing it is important to apply a top-dressing, although some people may decide to leave the tine holes open for longer periods of time, but they will need to be careful not to allow a thatch layer to spread sideways and cover over tine holes as this will prevent top-dressing from being worked into the holes beneath the covering thatch layer and can result in an even pock mark patterned appearance the following year when the weather is warm and dry.