Rainwater for use in the garden

We have recently had an enquiry about the use of rain water for the garden. A person was concerned about stagnant water potentially damaging their plants. They also wanted to explore environmentally friendly treatment in the water butt.

Fresh rainwater is good for your garden, but if it sits unused for many weeks it can lose oxygen, develop unpleasant odours and allow harmful microbes to build up. To keep your plants healthy please consider the following -

Cover and use regularly

Keep your water butt tightly closed or fitted with fine mesh, and draw off water at least every few weeks. Regular turnover prevents stagnation and maintains oxygen levels.

Barley-straw pack for algae control

A barley-straw pack is a small mesh bag filled with dried barley fibres. Float one pack on the water surface and, over a few weeks, it releases natural compounds that inhibit algae growth. It’s fully organic and chemical-free. Replace the pack every three to four months or when it breaks down.

BTI mosquito dunk to prevent larvae

A BTI mosquito dunk is a donut-shaped tablet you float in the butt. It contains Bacillus thuringiensis israelensis, a naturally occurring bacterium that kills mosquito larvae but is harmless to plants, birds, fish and pets. Each dunk treats up to 100 L of water for about 30 days.

Horticultural hydrogen peroxide to refresh foul water

If the water ever smells foul or looks very murky, add about 50mls of 3% hydrogen peroxide per 100 litres of water. The extra oxygen bubbles help break down organic debris and boost oxygen levels. The peroxide then rapidly decomposes into plain water and oxygen, leaving no harmful residue.

All of these things should be readily available in most garden centres.