Good drainage is key to a healthy lawn but as anyone who lives in the UK will know, this isn’t always easy to achieve. Frequent downpours and moisture-laden conditions mean that many lawns will become soggy and spongy in the cooler months of the year. If you have heavy clay or compacted soil, a waterlogged lawn will be more common.
Fortunately, there are a few steps that you can take to improve lawn drainage and prevent waterlogging from happening in the first place. Improving the health of your lawn, aerating the soil, installing drains or trenches and creating alternative water collection areas can all reduce or prevent waterlogging.
Keep reading to find out how to remedy saturated soil and how to create drier, airier conditions for your lawn grass to thrive.
What is a waterlogged lawn?
A waterlogged lawn occurs when there is more water on the surface of the lawn than it can absorb. The water displaces air particles in the soil so that the roots of grass and other plants can’t absorb oxygen and will drown if submerged for long enough.
In waterlogged gardens, pools of water will sit on the surface of the grass and drain away very slowly. Waterlogging usually happens after long periods of heavy rain and if you regularly experience a waterlogged garden, clay or highly compacted soil is likely to be part of the problem.
At best, a waterlogged lawn will be squelchy and sticky, at worst, there will be visible pools of water that may remain on the grass for days or even weeks.
What causes waterlogged soil?
During prolonged downpours of heavy rain, the soil becomes saturated. If the rain keeps on pouring, the soil will eventually be unable to absorb any more water, leading it to pool on the surface instead. Waterlogged soil feels soft and squishy and you’ll be able to hear the soil squelch underfoot if you walk across it.
Waterlogging is more common in clay and compacted soils as there are fewer air particles for the water to pass through. Waterlogging can also be caused by poor soil preparation before laying turf or seeding.
Why is a waterlogged lawn a problem?
Waterlogging can cause problems for your lawn for many reasons:
- Excess surface water will limit the amount of oxygen that reaches the grass roots.
- Damp conditions will increase the growth of algae, liverwort, lichens and moss.
- Grass can be pretty tough and a few days underwater shouldn’t cause too much damage. However, long-term waterlogging may cause the grass to yellow and die, creating bare patches on the lawn.
How to fix a waterlogged lawn
Although it may seem like a daunting task, there are several ways to improve drainage in your lawn. If your garden is covered in pools of water, you might be wondering how to drain the waterlogged ground. We’ve put together a handy list of waterlogged garden solutions to help you dry out your patch once and for all.
Before you attempt the soggy lawn solutions below, you’ll need to wait for any excess water to drain away. Here’s how to drain a waterlogged lawn:
Using a tool like a garden fork to prick or slit the surface of the ground will help to improve drainage, however, you may end up causing more damage to the lawn by walking on it when it’s waterlogged than you would if you left it to drain away naturally. All of the following waterlogged garden solutions are best done once the water has soaked away.
How to improve lawn drainage and prevent waterlogging
1. Aerate the soil
If your lawn is on the smaller side, you can use a garden fork or hollow tine aerator to punch deep holes in the soil. You can use a towed aerator for larger areas. Soil aeration helps to prevent compaction, allows plants to absorb more nutrients – leading to a thicker, healthier lawn, and improves airflow, ultimately reducing the risk of waterlogging.
You can also consider airblast aeration, where compressed air is blasted into the soil in different directions from a depth of 1 metre. It’s an effective, long-lasting solution for compacted soils.
Adding sand to an aerated lawn will help to aid drainage further.
2. Improve lawn health
It sounds obvious, but the healthier the lawn is in the first place, the less likely it is to become waterlogged and even if it does, it’ll bounce back much more quickly.
A strong, healthy lawn will play a key part in your waterlogged lawn remedy plan. Unhealthy lawns usually contain weeds, moss and bare patches. It’s essential to remove these if you have problems with soggy soil.
Use a suitable moss killer to treat any problem areas, make sure to keep your lawn regularly fertilised and overseed when necessary. A strong grass root system should help to reduce waterlogging problems in the future.
3. Dig a soak-away trench
Digging a trench is one of the most effective ways to prevent waterlogging. Drainage trenches can be particularly useful in clay soils which are easily compacted.
Your soak-away trench will need to slope away from the garden and be at least 2 feet wide and 2 feet deep. Make sure you check for any pipes that might be lurking underground before you begin. You’ll need to fill the ditch with around 12 inches of brick rubble followed by 3 inches of gravel then cover it with soil.
4. Install a French drain
French drains, so-called because of an American farmer called Henry French, who wrote about them in 1959, are an effective way to divert water away from the lawn and into a drain.
To create a French drain, you’ll need to dig a trench that’s at least 18 inches deep and 9 inches wide. The trench needs to slope downwards, at least 4cm for every 2 metres of trench length. Make sure you check for any pipes that might be running underneath the soil.
Line the trench with water-permeable landscaping fabric to prevent any plant roots from clogging up the drain. When planning your drain’s location, you’ll need to decide where the water will drain off to.
Next, fill the trench with around 3 inches of gravel, before laying a perforated pipe. Once the pipe is in position, you can cover it with a layer of landscaping fabric, before topping it up with fine gravel. You can leave the gravel showing, or cover it over with turf, depending on its location and your preference.
5. Create alternative water collection areas
Another way to help prevent lawns from becoming submerged and soggy is to try to reduce the amount of water that flows onto it.
If you have garden structures like sheds and greenhouses, drain the water that runs off the roof and collect it in a water butt. It’ll help your grass to stay a bit drier and provide water for the plants that need it during dry spells.
Installing permeable paths in your garden is an effective way to soak up excess water. Paths made from bark chippings or shingle will work well, or you can lay a path with permeable paving stones which allow the water to flow into the sub-base drainage layers.
6. Plant a bog garden
An alternative way to make the most of poor draining areas in your lawn is to plant a bog garden. Bog garden plants won’t survive in badly waterlogged areas, but they will thrive in moist soils and they’re a great way to attract wildlife to your garden. If you have a patch of soil that remains damp all year round, you may not even need to use a pond liner at the base of the bog garden.
Plants such as hostas, water irises, many types of grass, astilbe and the striking cyperus are all excellent plants for a bog garden.
Waterlogged grass can be fixed
Waterlogged grass can be a real problem, especially on lawns with heavy clay or badly compacted soil. Fortunately, there are several solutions for saturated soil. From ensuring your grass is as healthy as it can be to keeping to soil aerated and diverting the water away from your lawn, a boggy garden can thankfully become a thing of the past.