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How to Store Rainwater for Plants

How to Store Rainwater for Plants

Did you know that for every inch it rains on a 1000-square-foot roof, you can collect up to 600 gallons of rainwater? Unfortunately, most of this water goes to waste because of the unreliable storage options most homes use.

It is pretty overwhelming, and our plants endure the worst during summertime, more so when water consumption is limited to household use only. Definitely, something needs to be done, and the sooner, the better.

Well, I am a big subscriber to trying out stuff that works out, and today I will be sharing some of the methods on how to store rainwater for plants.
Are you ready for this thrill? If yes, let’s dive right in.

How to Store Rainwater for indoor Plants

For a long time, I struggled with watering my indoor plants for the simple reason that there was no water available. Often it happened during the summer when authorities rationed water usage.

But as you know, indoor plants don’t consume that much water. So I needed to find practical solutions to ensure my plants pulled through the season. That involved collecting and storing rainwater. To say the least, the results were astonishing.

1. Plastic Water Bottles

We all know how devastating plastic water bottles are to the environment. How about killing two birds with one stone?

Well, you can collect plastic water bottles, as many as you want, and fill them with rainwater, then keep them in a cool place. It could be your backyard or basement.

Ensure that you tighten the tops so that no pathogens penetrate inside. When summer comes, you can use bottled water to irrigate your indoor plants and keep the bottle safe until the rains come again.

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2. Jerry cans

Forget the compressed steel 5.3-gallon oil jerry cans used during the Second World War. Nowadays, there are plastic water jerry cans often used when people go out camping.


Usually, they store water but can also carry oil, fuel, and other liquids. If not in use, fill them up with rainwater and keep them in a cool environment away from the sun.

Bonus tip: Ensure you label the container properly since someone can easily mistake it for oil.

Here are some Jerry cans:

3. Rainwater butts

If you thought that storing rainwater for your plants couldn’t get any better, well, rainwater butts provide an even more unique solution. They come in different shapes, sizes, and colors, and with accessories such as taps and stands.

Usually, they collect roof water through the gutters and store the resource until when you need it. Often people mistake them for barrels, but they still function the same way despite the few disparities.

How Long Can I Store Rainwater for Plants?

While dealing with this question, I came across various opinions from different people with varying experiences. Most of them said indefinitely, meaning rainwater could last for as long you want.

But there is a catch to this. The storage vessels needed to be well covered to prevent pathogens and debris from falling inside. More so, open vessels can be perfect breeding grounds for mosquitoes.

Therefore, picking a suitable storage vessel is key to ensuring long shelf life for the rainwater. But that’s not what some thought.

They suggested that when the rainwater is sterilized or boiled and then covered perfectly, it should last a lifetime, which I also agree with.

But then, do you need to sterilize or boil rainwater for your plants? Sounds like quite some tedious work which of course you don’t have to do.

All you need to do is ensure that your rainwater vessel is adequately covered to prevent the entry of organic material, insects, and other detritus, and you are guaranteed the water will last for as long as you want.

See also: How to measure rainfall using rain gauge at home

How to Filter Rainwater for Plants

While most people assume rainwater is very pure, usually, it is not the case. It gets contaminated with debris such as leaves, dust, and other organic materials. Such might not be what your home garden and plants necessitate.

It is crucial to eliminate the debris from your rainwater through filtration to ensure it’s safe for the plants. In fact, filtration is the most significant step one should take on any water harvesting method, no matter the size.

But how is filtration done?

Most people harvest rainwater from their roofs, and often, leaves and other detritus are washed into the gutters. Therefore filters are installed in the downspouts to trap the debris from getting into the collecting vessels.

Choose the best filter you can afford but ensure it is adequately sized for your gutters. A good one will eliminate leaves, feathers, and other debris. Also, ensure you have it at a place you can easily access and clean when necessary.

Bonus Tip: If you can’t afford a filter, you can use a regular kitchen rag or sieve to filter the water into your storage containers.

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How to Store Rainwater for Your Garden

During the summer, most backyard gardens get scorched dry simply because there is a limited amount of water for the plants. But that shouldn’t be the case given the heavy rainfalls a few months ago.

This calls for gardeners to learn how to store rainwater for plants.

Method 1: Install Rain Barrels

If you live in arid areas, you understand how frustrating it gets when you have to water your garden, but unfortunately, you can’t do so due to authoritative restrictions. However, if you had a rain barrel, you could have stored rainwater for use in your garden.

Usually, rain barrels receive water from the roof flowing through the gutters, then to the downspouts and into the barrels. You can connect two or more barrels together using pipes such that when water fills in one, the excess fills the other tanks.

When the rain is over, cover the barrel with a lid to prevent pathogens and entry of other detritus.

Also read: pros and cons of rain barrels

Method 2: Install Underground Rain Harvesting Tanks

If you think rain barrels are too small for your garden, maybe you should install an underground rainwater tank. One great thing is that the underground tanks come in various sizes, so don’t worry if you have just an average garden.

But the larger, the better because you get to store a lot more water.


Unfortunately, this isn’t a DIY process. You have to get the services of a professional contractor to excavate the land.

You can choose to install a readymade plastic or steel tank in the ground or have the contractor construct a concrete tank. All the same, they provide safe water for your garden, just that one is more permanent than the other.

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Method 3: Installing Above Ground Rain Harvesting Tanks

Above-ground water tanks work similarly to rain barrels, but they store a lot more water. Like barrels, they receive rainwater from the roof through the gutters and direct it into the above-ground tanks.

They also come in different shapes and sizes, some made of plastic while others steel. This gives you an array of options to choose one that fits your garden. Once installed, always cover the top of the tank to prevent the entry of pathogens and debris.

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How to Store Rainwater Long-term

When I see rainwater flowing down the streets, it gets to my nerves, knowing very well that a time would come when we really need this resource. For those who wear my shoe, I am pretty sure you understand how important it is to store rainwater for the long term.

To even think of storing rainwater for a long time, you are obviously thinking of large quantities. Not to say that you can’t keep little amounts for a long time. Of course, you can. But how do you go about this?

Well, the first thing you need to do is ensure the safety of the water.


For one, you need to install filters in you your gutters to get rid of detritus and other organic materials. Also, because you are dealing with large quantities, you can use ultraviolet sterilization to kill harmful pathogenic microorganisms present in the water.

Regardless of your storage vessel, it could be an underground tank, barrels, or above-ground tanks; you need to keep them always covered. Remember, disease-causing pathogens can get into the water once the treatment wears off.

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How to Store Rain Water for Plants: Frequently Asked Questions

Can I water plants with stagnant water?

If the stagnant water was stored properly, there is no point whatsoever to deny the plants a chance to blossom. But you need to be very careful with improperly stored stagnant water since it may contain parasites and diseases that may affect your plants.

How long will rainwater keep?

If you wonder how long you can store rainwater, don’t get surprised when I tell you indefinitely. For this to happen, the water needs to be free of any debris contaminants and covered correctly to prevent the entry of other foreign materials.
With this practice in play, you can store your rainwater for as long as you want.

Is collected rainwater good for plants?

Rainwater is suitable for plants. In fact, there are traces of nitrates in the water, which are ideal for their growth. More so, tap water has additives such as chlorine which may not be ideal for human consumption.

No doubt plants need water to survive. But it so happens that there is little to no water during the dry season, which leaves us with no option but to learn how to store rainwater for plants.

Don’t get discouraged by the tedious processes involved. If anything, you should be happy because you now have a solution for your plants.

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