I protected my new build garden from waterlogging with this smart soil improver tactic – two years on, it's been a lifesaver
Mulch saved my garden
New builds have a reputation for having terrible, water-logged gardens, and when we moved into ours in 2024, it looked like ours would be no different. The clay soil was heavily compacted: rain would pool on the surface, and whenever we dug deeper, we would very quickly hit pockets of water that gathered like underground puddles. What's more, there was no life in the soil at all – no worms, no bugs, no spiders, nothing.
As a keen gardener, I realised that if I wanted to bring my new build garden ideas to life, I would need to improve the drainage in my clay soil.
What I did to stop the soil waterlogging
My first port of call was to research how to improve clay soil for gardening. I quickly realised that I desperately needed to add some organic matter to the soil.
'The simplest way to improve clay soil for gardening is to incorporate bulky organic matter such as compost or farmyard manure, as well as some sand and grit,' advises Julian Palphramand, head of plants at British Garden Centres. 'This will improve soil fertility, aeration, drainage, and moisture retention.'
However, that only opened up the question of what to use. I wanted something that would be effective, sustainable, and also budget-friendly.
This led me to discover Mushroom Compost. We moved into our new home in May, and by the third week of June, I had taken receipt of approximately 1000 litres of Mushroom Compost, which, I hoped, would offer the solution to my waterlogged soil problems. This Mushroom compost from B&Q is similar.
Why mushroom compost?
Mushroom compost is not made from mushrooms, but is actually a by-product of the mushroom-growing industry – typically made of a mix of straw, hay and poultry or horse manure.
When dug into beds and borders, its fibrous nature makes it ideal for breaking up heavy soils and increasing aeration in the soil, as well as adding nutrients back into the soil. 'Mushroom compost is particularly useful, as it contains no weed seeds. Mulching brings many benefits, including adding nutrients, protecting plants from frost, reducing weeds, and improving the soil’s ability to retain moisture during dry periods,' says David Glass, head gardener at Bowood House & Gardens.
However, it is important to ensure that it is peat-free – such as this from Garden Scapes UK – as some are not.
How did I use it?
If I were following best practices for mulching, I should probably have waited until autumn – the ground would have definitely been more workable and less concrete-like. However, I had pots of plants that needed to go in the ground, and I was sick of looking out onto a garden full of weeds.
Over the following week, we started the back-breaking work of using a garden fork – we used this Kent and Stowe one available from Amazon – to dig in the mulch and break up the clay. It is recommended that you use a 75mm layer for very poor soils or a 50mm layer for general soil improvement.
Did it work?
Undoubtedly! Since digging in the mushroom compost, we have never had issues with pooling or waterlogging, and the soil is full of insects, worms and wildlife.
It has also had a positive effect on our plants. Our roses are flourishing (they've tripled in size since we planted them a few years ago and we've even grown three very healthy lavender plants, which normally would struggle to thrive in clay soil.
Maintainance
Once our plant got established, I top-dressed the garden with bark mulch – like this from B&Q. This was primarily an aesthetic decision and helped stop the weeds taking over my garden. However, over the past two years, it has started to decay into the soil, further improving its nutrient level and consistency.
The contrast between the back garden, where the soil is very workable, and the front garden (which we did not treat anywhere near as extensively) is evidence of the mushroom compost's success. Recently, we had to wait for a few rainy days before we could plant in our front border, as the soil was impenetrable after a few dry days – this was not an issue in our back garden.
Waterlogging is not so much of a problem in the front garden, as the soil is very shallow, and we worked a small amount of mulch into any very compacted clay areas we identified. However, in the back garden, improving the soil was a game-changer in ensuring I'm not battling waterlogged garden beds after every heavy downpour.
If you don't have the time to improve your soil, a water butt can be a smart solution to channel any extra water run off and store it to use during a heatwave.
If you are having significant drainage or flooding issues in your garden or around your garage, a floor barrier might be the best solution to help channel water away from vulnerable areas.
