How to deal with a waterlogged lawn - An article by Allett

An excellent article from Allett manufacturers of both petrol and battery powered Cylinder Lawnmowers about dealing with waterlogged lawns. 

 

It's that time of year again! It's either very cold or very wet! We've had it mild and wet over the last few weeks and this has resulted in some very wet lawns. If your lawn is particularly wet you may have some serious issues; similarly if your lawn gets very dry in the summer you may also have serious issues- this often evolves around thatch levels and compaction effecting drainage. Preventing water-logging is very much about the work you do to your lawn all year round. 

 

HOW TO TELL YOUR LAWN IS WATERLOGGED 

 

You will see surface water on top of the lawn that sits there for quite some time. 

Your lawn will be squelchy to walk on 

A glue-like layer of puddled soil may form near the surface, which is made worse by walking on the lawn. Try to keep off a waterlogged lawn where possible 

Your lawn will eventually turn yellow and die out 

Each lawn is different in terms of drainage. There are many factors involved such as; 

 

1) Type of soil - Most lawns in the UK consist of clay soil. Soil that is rich in clay is prone to flooding as the soil is denser and doesn’t allow air or water flow as easily. 

 

2) Thatch levels- lawns that aren't scarified monthly will have bad thatch levels. Thatch stops water from passing through into the soil meaning the rainwater just sits on top and has nowhere to go. 

 

3) Position of the Garden- If your garden is situated at the bottom of a hill the water will be running down onto it regularly. 

 

4) How flat your lawn is- If lawn has an uneven surface this will allow excess water to form puddles 

 

5) Compacted soil- if you don't aerate your lawn regularly and your lawn receives high traffic eg children /people walking over it the soil will be compacted meaning the water has nowhere to go. Aerating regularly will help solve this. 

 

6) Hard landscaping- A lot of new houses have patios etc meaning water can't drain though. If you live next door to someone with an artificial lawn this can also have serious consequences. 

 

7) Gutters and down-pipes not connected into the drainage system 

 

8) Poor root system- You need a thick well developed root system to help absorb the water. Bad thatch levels can make the roots shorter as they have nowhere to go. Over-seeding in the spring can help create a thicker lawn as well as regular scarifying and verticutting. 

Most lawns will tolerate some rainfall until it reaches a saturation point beyond which it is unable to drain away any additional water. This results in the water pooling on top of the soil. Your grass will become vulnerable when it’s subjected to prolonged spells underwater. 

 

The issues water-logging can cause include; 

 

The grass roots will die off, promoting rot and decay as well as the killing of the grass itself. 

The excess water will reduce the supply of oxygen 

It also reduces the diffusion of Carbon Dioxide. 

Essential nutrients wont be absorbed leaving the soil starved- you may spot this by the colour of your lawn at times- it can look very yellow. 

The soil can become compacted by the water. 

As the grass dies spaces are created for moss and weeds to invade. Lichens and liverwort love the damp conditions and can eventually cover wide areas of the lawn. They will stifle grass growth and kill your lawn. 

Moss loves wet conditions. Worms also love wet conditions which then attracts moles. 

 

WHAT CAN YOU DO TO PREVENT OR SOLVE A WATERLOGGED LAWN? 

 

Regular aeration of your lawn is key. Once a year is often sufficient. Using a hollow tine aerator is the best way of aerating your lawn as you can aerate as deep as 4-5inches deep. Alternatively you can use Allett's aerator cartridge throughout the season however bare in mind this is a tool used simply to break up the surface crust and penetrates no deeper than 5mm. The lawn can also be spiked with a garden fork creating large holes in the lawn for water to pass through. Try and stay off your lawn if it is severely waterlogged until it has naturally drained. If it is under water for more than a week you may have serious issues. Are there certain problem areas which pool water more than others? This might be due to an uneven lawn, where the water has nowhere to run, or through a particularly compacted area. The flooding issues may be nothing to do with the lawn itself but external factors. 

 

It is important to scarify at least once a month in the mowing season with the Allett spring rake scarifier cartridge. This is a great cartridge for removing thatch and moss as well as picking up any surface debris. Thick thatch levels can create a barrier for water preventing it from being absorbed into the soil resulting in it just sitting on top of the lawn. Lawns with bad thatch levels will be very dry in the summer for that reason whilst being waterlogged in the winter. 

 

If your soil has a particularly high clay content and you are having issues every winter with water-logging you may want to look at changing it. If you do choose to replace it, lay any new turf or seed on generous amounts of sand and loam topsoil. Sand drains well- you may hear of sand based football pitches coping really well with rainfall. 

 

Applying fertiliser in spring will help your lawn recover from winter damage and to grow a more extensive root system.