How to improve soil drainage

Waterlogged garden? Here's how to fix it

After heavy rain, puddles form across your garden. Your lawn turns into a muddy mess and plants sit with their roots underwater. Sound familiar? Your soil has a drainage problem. The good news: you can fix it without ripping up the entire garden.

GardenWorld helps you visualise a garden design suited to your soil type. A well-drained garden starts with a smart plan.

Why does your soil drain poorly?

The most common causes are clay soil, compacted layers and a high water table. Clay consists of tiny particles packed tightly together. Water barely passes through. Compaction builds up from years of walking or driving over the same spot. And if the water table is high, rainwater simply has nowhere to go.

The percolation test

Dig a hole 30 by 30 centimetres and 30 centimetres deep. Fill it with water and let it drain. Refill and measure how fast the level drops. Less than 2.5 centimetres per hour? You have a drainage problem.

Organic matter: the easiest fix

Compost, leaf mould and well-rotted manure improve soil structure. They loosen clay and create channels for water to pass through. Work 5 to 8 centimetres of organic matter into the top layer every year. It's the cheapest and most natural approach. Garden centres stock bagged compost in bulk.

Working in grit and sand

Where you plan to plant, place a layer of gravel at the bottom of the planting hole. This gives roots a chance to stay above waterlogged soil. Mix sharp grit through clay to open up the structure. Use at least 5 centimetres per square metre, thoroughly incorporated.

Digging trenches and channels

A gravel trench is an invisible drain. Dig a channel about 30 centimetres wide and 60 centimetres deep. Line it with gravel, cover with landscape fabric then soil. Water flows through the gravel to the lowest point of your garden. Perfect alongside a path or border.

Laying drainage pipe

For serious cases, drainage pipe is the answer. That's a perforated pipe laid in a gravel bed with a slight fall. Water seeps through the holes and flows to an outlet. DIY stores sell complete drainage kits.

Building raised beds

Don't fancy working underground? Build raised beds and fill them with free-draining soil mix. Water runs out naturally. This is the quickest fix for a veg patch or ornamental border on wet clay.

Plants that tolerate wet feet

Some plants don't mind wet ground. Iris, astilbe, reeds and willows thrive with extra moisture. Plant them in the wettest spots and you turn a problem into a feature.

Maintaining drainage

Check trenches and pipes annually. Leaves and silt can block the flow. Flush pipes with a garden hose. Keep the ground around drain outlets clear of soil that might seal the opening.

Harvesting rainwater

A water butt catches rain before it floods your garden. That eases pressure on the soil and gives you free irrigation water during dry spells. Win-win.

Dry feet for your plants

A well-drained garden is a healthier garden. Plants grow better, roots don't rot and your lawn recovers faster after rain. Start with the simplest solution and scale up if needed. Design a garden with good water management at GardenWorld and enjoy dry feet all year round.