Maintenance Outdoor Gardening

Why Rainwater is Better For Plants Than Tap water

I love rainy days. Besides the melancholic mood, it’s lovely to rug up on a rainy day. Not to mention, listening to the therapeutic sound that rain makes on the roof and surrounding areas. Most of all, I feel pleased about my garden and plants getting a deep soak of beneficial rainwater. It helps too that leaves are being naturally cleaned at the same time.

Rainwater is beneficial to gardens

Have you ever wondered why plants seem to have a lush green appearance, look cleaner after experiencing some rainfall? Somehow plants seem to exude happy vibes after rain. Yet, watering them with a hose or a watering can doesn’t quite achieve the same feeling.

The answer lies in chemistry.

Rainwater has less harmful chemicals than tap water

Tap water usually has chemicals like fluoride and chlorine, which may cause damage to plants. Fluoride may injure plants with long, slender leaves, such as the spider plant. High levels of chlorine may accumulate in indoor potted plants over time, which could be toxic to them.

Rainwater contains more oxygen

Rainwater contains more oxygen than tap water. If you ever wondered why your plants don’t seem to suffer from root rot or other damage after heavy rains, oxygen is the reason. Waterlogging may bring about anaerobic soil conditions (ie. lack of oxygen) and lead to root rot if you overwater your plants with tap water. However, rainwater is highly oxygenated and therefore, even when soil is saturated after a downpour, there is no danger of root rot since anaerobic soil conditions do not develop.

Rainwater has a slightly acidic pH

When it rains, carbon dioxide is also introduced to the garden environment. Carbon dioxide combines with other minerals in the atmosphere and makes rainwater a little acidic. When this acidic rainwater wets garden soil, minerals such as zinc, manganese, copper and iron that are essential to plant growth are released.

Rain falls uniformly & leaches soil

Rain tends to fall uniformly throughout the garden, which means that it leaches the soil down beyond the root zone, getting rid of salts which may have accumulated in the soil and inhibit plant growth. This is the reason why plants seem to explode in growth after a rainy spell.

Lightning & Nitrogen

Plants require nitrogen to produce the green pigment known as chlorophyll which is needed for photosynthesis. If plants suffer from nitrogen deficiency, their leaves will turn yellowish. We would usually introduce nitrogen to the soil in the form of fertiliser. The decomposion of organic matter in the soil also releases nitrogen. However, lightning plays the biggest role in the nirogen cycle in that it generates enough energy to break down atmospheric nitrogen. This nitrogen then mixes with oxygen and water, resulting in rainwater which contains high levels of nitrates and ammonium required by plants.

In conclusion, now that you are aware that rainwater is more beneficial to your garden and plants than tap water, you may wish to consider installing water tanks in your garden, so that you can collect precious rainwater for regular use!