It seems common sense once you think about it, but many of us haven't! Mains water is designed to be perfect for human consumption via a series of chemical additives and cleaners that kill micro organisms and provide minerals that are good for our growth, however to a plant mains water is far from perfect and that means that harvested rainwater is always better for them! But what is the effect of watering your plants with mains water and what are the benefits of using natural rainwater?
How does mains water harm plants?
Mains water has several additives that cause plants harm:
- Chlorine kills micro organisms that benefit plants and actively damages the plant itself
- Fluorine compounds and its simplest anion Fluoride can affect plants very badly, pale dying leaves are a symptom of flourine damage and this has been known since 1950. Some plants can tolerate fluorine compounds better than others however those with delicate leaves are much more susceptible to fluorine related tissue damage
- Sodium and other water softeners, though natural in their properties, do not appear in such quantities in natural water, these softeners often damage plant roots and prevent the absorption of water by the plants roots
- Mains water is simply put, much harder than rain water. As water evaporates its leaves behind all of the minerals it contained as a liquid, this means that rain has a far smaller mineral weight than mains water, this means that by watering your plants with such hard, mineral rich water you are potentially harming your plants. Just as your washing machine may suffer from hard water so may your garden.
How does rainwater benefit your plants?
- Rainwater is much softer than mains water, this means it has a better ability to absorb existing natural minerals from the soil and transport these minerals to your plants!
- Harvested rainwater after a period of time will grow a small amount of micro life such as algae. Far from being dangerous, algae will quickly decompose into the soil and act as a small fertiliser, giving nutrients and beneficial compounds to your soil. Though algae is poor for human health making harvested water not for human consumption, plants love it!
- Rainwater is a valuable source of nitrogen which encourages natural healthy growth of plants when absorbed through the roots!
In short natural harvested water will help make your plants and flowers look better and will make your fruit and vegetables even more wholesome and healthy. It can be impractical to only use harvested water if you don't want a large and complicated water harvesting system but even a small downpipe diverter to water butt will do your garden a world of good!