Is rainwater good for houseplants? Why a rainy summer is actually a good thing

With the rainy weather upon us, we are trying to find anything positive in the idea of a rainy summer. And the one question we’ve been asking ourselves when thinking of the rainy spell is - is rainwater good for houseplants? 

We know it's ideal for outdoor plants, but it turns out that using rainwater to water your houseplants could be one of your best houseplant ideas yet to keep your plant babies happy.

Even though some houseplants are very easy to care for, tap water is not the most ideal kind to water them with. Instead, harvesting rainwater to water them will do them the world of good.

Is rainwater good for houseplants?

‘If you’re trying to be the very best plant parent, you’ll be pleased to learn that many houseplants love being watered with rainwater,’ explains Jo Lambell, founder of Beards & Daisies. 

‘Rainwater is classed as ‘soft’ water naturally, meaning it’s free of many salts, minerals and chemicals that you’d typically find in treated tap water. Not only is it more gentle on your plants, but it can even help promote growth.’ This is apparently down to the presence of nitrates in rainwater, which are proven to help with plant growth and come from the nitrogen in the Earth’s atmosphere.

Those tap water additives are there to make it safe for humans to drink. But plants have very different needs from humans. 

‘These minerals can actually have a negative impact on our plants,’ continues Steve Chilton, gardening expert from LeisureBench. ‘Rainwater is minorly acidic. This means that when you use rainwater on your plants, you're helping to balance out the soil's pH, which might be a bit off if you've frequently been using tap water to water them.’

This sustainable hack is also a great way to save some extra cash. ‘Conserving natural resources like water will be so helpful if we see a drought this summer, and it can also do wonders for lowering your water bills,’ says gardening expert and author, Sarah Raven. 

How do you actually go about collecting this precious yet free water source? Our experts recommend getting a water butt. ‘Place the water butt outside in an uncovered area, and it steadily collects rainwater until it's full,’ Steve advises. ‘Most water butts will have a tap, which allows you to use it like you would with any tap/water system.’

But if your outdoor space is very limited (say you live in a flat), something smaller will do. 'Placing large containers outside when it rains will do the trick too. Once used on your plants ensure you clean the containers well and keep them handy for the next downpour,' says Suzie Woolley, plant expert at Serenata Flowers. 

So water your plants with rainwater and they will love you for it, it turns out. Not to mention your wallet and the planet.