A waterlogged lawn is a very fragile thing and can be completely destroyed in a few minutes by heavy boots or an quick game of football. This post is to just take a look at why the a wet lawn is susceptible to damage, how to prevent it, and how to bring it back if it does end up turning into a mud bath!
The majority of the UK has experienced an extremely damp start to 2014. With record rainfall levels and flooding affecting a lot of the South East. Up here in Manchester we seem to have dodged the worse of it, but have still seen much more than usual.
How do I know if I have a waterlogged lawn?
An excessively waterlogged lawn is very easy to spot. If you have had a lot of rain over a number of weeks then you may start to notice that the tips of the grass will start to turn yellow. This is a sign that the roots are struggling to breathe and the plant is pulling in its reserves to try and prevent death. Grass is extremely hardy and can survive for a number of days flooded, but will certainly perish if underwater for any prolonged period.
If you step on the lawn you may also notice the soil feels “squelchy” underfoot and water does not drain away from the surface. In severe cases there maybe puddling on the soil. This is all a symptom of poor drainage, with the water not being able to escape quickly enough into the sub-soil or run off.
Why is excess water bad for your lawn?
A healthy soil is full of pockets of air. These enable roots of plants and micro-organisms which live in the soil to breathe. If a soil becomes waterlogged, all of the air floats to the surface and is lost to the atmosphere. The extra weight of the water closes these pockets and the soil becomes compacted, preventing it from breathing and so plants rot and eventually die. This is a real problem for grass.
How to limit damage to a waterlogged lawn.
The main thing to do is STAY OFF A WATERLOGGED LAWN! This cannot be stressed enough. Any pressure on wet soil squeezes out more air which then cannot be replaced and the result will be a very compacted and dead soil.
The second thing you need to address is drainage. If you find that you regularly have a waterlogged lawn, even in times when other parts of the garden are not suffering, then you need to look at improving this for the long term.
Things to consider are:
- Try to fill in any depressions and level any areas which tend to puddle. This will help water drain off the lawn.
- When the lawn is dryer, hollow-tine aerate and then brush sharp-sand into the open holes. This helps to keep the soil structure open and aids water movement through the soil.
- Regular top dressing will help keep the soil healthy and level.
- A French drain system can be installed to help move water away from the problem area.
- Some plants can be planted to help garden drainage. Some conifers and other trees will suck up hundreds of gallons of water from the soil, helping problem areas.
Fixing a lawn ruined by waterlogging
In many cases, as long as the wet has not been too long or the lawn hasn’t been used while wet, most grasses will recover from a wet spell easily. However, if you have heavy damage then follow the following steps to bring the lawn back to life:
- Wait until conditions improve and the soil is warm (at least 8 degrees Celsius is needed for grass seed germination).
- Aerate the area well. Spiking deeply is advised, but a professional hollow-tine aeration treatment is recommended.
- Brush in a layer of sharp sand. NOT builders sand which can contain salts and other impurities, but a horticultural sharp sand.
- Overseed the area with an appropriate grass seed. Some grasses can tolerate damp roots much better than others.
- If necessary, cover the area with a light layer of topsoil or compost, to give the seed a good medium to germinate into.
- Keep it lightly watered to help the seed to take and then let it establish before mowing.
Follow these steps and it will recover quickly.