In the UK, we get our fair share of rain so why not make the most of it? Rainwater harvesting is a simple, eco-friendly way to collect and store rain for use in your garden. It saves money, reduces your environmental impact, and helps keep your plants happy and hydrated.

At Wild Roots Gardening, we’re all about working with nature and rainwater is one of our most precious free resources.

💧 Why harvest rainwater?

Save money: Reduce your water bills by using free rainwater instead of tap water.

Better for plants: Rainwater is soft and free from chemicals like chlorine, which makes it gentler on your soil and better for plant health.

Eco-friendly: Less demand on mains water means lower energy use and a smaller carbon footprint.

Reduces flooding: Slowing the flow of water helps prevent overwhelmed drains and localised flooding.

🛠️ Setting up a rainwater harvesting system

You don’t need a fancy setup to get started just a few basic bits of kit and a bit of know-how.

1. Collecting rainwater

The easiest way to collect rainwater is from your roof. Rain runs down into the gutters and through the downpipe all you need to do is divert it.

You’ll need:

A water butt (or more than one, if you’ve got the space)

A diverter kit (fits into your downpipe to direct rain into the butt)

A lid to keep out debris and mosquitoes

A tap or hose connector at the bottom

Most garden centres and DIY shops sell complete kits, or you can repurpose a large barrel or bin (just make sure it’s food-grade and has a secure lid).

2. Choosing the right spot

Place your butt near a downpipe from your roof, shed, or greenhouse.

If you want gravity-fed watering, raise the butt slightly on bricks or a stand.

Keep it shaded if possible less algae growth.

3. Overflow and multiple butts

Add an overflow pipe to drain excess water once full.

Link several water butts together with a simple connector kit to maximise storage.

🌱 Using your harvested rainwater

Rainwater is perfect for:

Watering vegetables, flowers, and shrubs

Topping up ponds or bird baths

Indoor plants (if stored in a clean container)

Avoid using it for:

Drinking (unless properly filtered)

Young seedlings if water has been stored for a long time and may contain algae

Top tip: Use a watering can or fit a hose attachment to your water butt tap. A soaker hose can be a brilliant low-effort solution just let it gently drip water right at the roots.

🌦️ Maximising your water collection

Clean your gutters regularly so water flows freely.

Install more than one butt if you have multiple downpipes.

Use a greenhouse or shed roof  even small ones collect a surprising amount of water.

Add a filter to stop leaves and debris from entering the system.

🧠 A quick bit of maths

Did you know?
Every square metre of roof can collect roughly 1 litre of water per 1mm of rainfall.
So, if you’ve got a 10m² shed roof and it rains 10mm you could collect 100 litres of water in just one shower!

🌍 Good for the garden, better for the planet

Rainwater harvesting isn’t just practical it’s a small act of sustainability that adds up. Whether you’re topping up your tomato patch or keeping your wildflowers blooming, you’ll be using what nature already provides.