Some sites aren’t naturally ideal for growing a first class lawn on and sometimes a lawn drainage system is required to enable the lawn to flourish. Poorly drained lawns are more often than not the result of a heavy clay soil and poor drainage can lead to waterlogged turf.
A poorly drained lawn will result in much reduced grass growth and a worst case scenario is that the grass roots suffocate due to lack of oxygen and the grass dies. Overly damp soil conditions also encourage the growth of lawn menaces such as moss and these can quickly take over the lawn and have a negative impact on the vigour and strength of the lawn.
Do you need a lawn drainage system? Many lawns will not need a drainage system installed but if your lawn is showing signs of poor drainage then laying a drainage system can help transform your lawn. If you don’t think that your lawn site will be prone to poor drainage and waterlogging then you may not need to install a drainage system. Double digging the site (dig the soil to 2 spades depths) should be enough to enable adequate lawn drainage.
When should I install a drainage system in the lawn? If you are creating a new lawn the best time to install the drainage system is before you have layed any turf / sown any grass seed. Install the drainage system after levelling the site.
A lawn drainage system usually comprises of one or more soakaway(s) and a drainage pipe system. A soakaway should be located at the lowest point of your garden and should be at least 1m square and dug to a depth of around 4-6 feet. Fill the soakaway with rubble and hardcore (large stones / broken bricks etc) up to around 1 foot from the surface. Add 6 inches of small stones / coarse gravel and then add a 6 inch layer of top soil to top up the soakaway to its original level.
Your drainage pipe system should consist of one or more main drainage pipes (depending on the size of the badly drained area) with smaller drainage pipes that lead into the main drainage pipe. The smaller drainage pipes should be arranged in a herring bone pattern (alternating on either side of the main drainage pipe at around 45 degrees from the main pipe. The main drainage pipe should lead to the soakaway.
Now we know when we and how we should take action against a poorly drained lawn lets look at how to install a lawn drainage system.