Can I Lay Turf in Wet Weather?

The problems that arise from turfing in wet weather are related not to the laying itself but rather to the preparation of the soil beforehand.

In preparing a bed for the turf great care should be taken to avoid compaction. What do I mean by compaction? A compacted soil is the opposite of a well-structured soil – and it's the well-structured soil that is what we're aiming at for optimum grass growth. A well-structured soil has got lots of air spaces interspersed between the soil particles so that grass roots can grow uninterrupted down through the soil. Compacted soil, on the other hand, has very little air space between the soil particles. Root growth is restricted leading to poor, stunted plants that are prone to the affects of drought and heavy wear.

It's difficult to compact dry soil, but when it comes to wet soil compaction can occur very easily. There is a further complication in that wet clay soils are much more prone to compaction than wet sandy soils. But why should this be?

In simple terms, all soils are made up of a range of particle sizes, but clay soils are characterised by having a high proportion of very fine particles with tiny air spaces between them. Sandy soils, on the other hand, are made up of larger particles with larger air spaces between them. And loamy soils are somewhere in between.

When a clay soil is dry it has great load-bearing strength. But when it's wet it becomes soft and sticky, and very easy to smear and squash. And when you squash a clay soil you squeese out the air spaces leaving a dense "poorly-structured", or compacted, soil. In these conditions grass finds it very difficult to grow. However, a wet sandy soil is not as easy to squash and is less prone to compaction.

So, going back to our original problem, you can see why care needs to be taken in preparing soil before turfing. During wet weather it's best to stay off clay or loamy soils. If you put machinery over them and try to work them into a fine bed you will smear and squash the soil and cause compaction. Even walking over wet clay soils will cause problems. The best thing to do is to wait until the soil is dry enough to work without sticking to machinery and boots. Patience is a virtue – many of the problems associated with lawns and turf can be traced back to the preparation of the soil in wet conditions. And it's very difficult to correct compaction once a lawn has been laid.