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How Long Can You Store Rainwater for Plants?

how long can you store rainwater for plants

Rainwater collection is quickly becoming a more and more popular method of choice for watering plants. With time spent at home now than ever before what better way is there to brighten up your house than with some wonderfully leafy plants or brightly colored flowers?

Rainwater is a great way to cut down on the cost of watering all your plants as it is both free and natural. Additionally, the lack of chemicals found in rainwater, such as chlorine which is used to make tap water safe to drink, is actually better for your plants’ health.

But how long can you store rainwater? Thankfully, the answer is you can store rainwater for plants for an indefinite amount of time. This means that you can always ensure that you have enough rainwater to keep your plants alive even in the hot summer months.

How Do You Store Rainwater for Plants?

The first thing to consider is how to actually store the rainwater. Rainwater will only last for an indefinite amount of time as long as you keep in good conditions. For this, you will need the right equipment. You will need to invest in a good-quality rain barrel if you plan on collecting a lot of rainwater or storing it for a long period of time.

However, if you only plan on needing a little bit of rainwater to keep your plants healthy then you can just as easily place any container outside to catch the rain.

For example, if you only have a few indoor plants that you need to water and do not plan to keep the rainwater for longer than one week then you will not need to buy any expensive equipment.

Instead, you can even place a large saucepan outside. As long as you ensure that the collected water is free of any contaminants then it will be perfectly fine to use this on your plants.

You can even store water using this method for up to one week. Beyond this, the water may need cleaning, but you can do this easily with a filter. If you live in an area where there is a lot of rain all year round then using a smaller container to catch fresh rainwater every week, or even every few days, may be a better option. 

Whatever your choice you will need to ensure that you are using a clean container and that it is free of any contaminants and bugs.

In order to do this you will need to place your container (be it jug or barrel) away from any structures, such as your house or garage) as well as from any trees. This will stop any dirt, sap, bugs etc. from falling into your container.

You can then simply leave your container here until you need it. Bear in mind that this type of storage works best if you empty the water regularly so that it does not become old and stagnant. 

We recommend using a rain barrel that is leak-proof and has a high capacity if you utilize rainwater for many daily chores. This collapsible rain barrel by Vingli is high-quality, portable, and reusable. It comes in 50, 66, and 100 gallon tanks.

How Do You Store Rainwater Long Term?

If you are planning to store your rainwater long term then you will need a much more advanced setup. For example, if you want to keep rainwater all year round in order to water your plants with rainwater in the summer when there is a lot less rain to catch then storing it correctly in the winter will help.

In order to store your rainwater long term, you will need to purchase good-quality rain barrels. Once you have collected the water you cannot simply leave them for months on end until you decide that you want to use them.

You will need to keep them clean. It is not actually the water itself that goes bad, but rather the environment. Since the water will be stagnant in the barrel it can be susceptible to algae growth, bugs (such as mosquitos) and other contaminants. 

This means that you will need to clean the barrel every week. To do this you have a few options. You can either clean them manually transferring the water from one barrel to another, filtering it in the process, and cleaning the barrel before replacing the water, or you can chemically clean it.

If you are planning on using your rainwater for plants then it is best to avoid using chemicals as much as possible as this can discolor and burn the plants. 

However, if you do decide to use chemicals in a bid to save yourself time and energy you will need to complete the following steps:

  • Install a filtration system
  • Paint the barrel(s) black (sunlight can increase algae growth)
  • Use oil. This will form a layer on the very top of the water and stop any mosquitos (or other bugs) from entering the water.
  • Use chlorine or iodine tablets. Be careful to monitor the levels of these chemical as they can cause toxicity for your plants.

How Long Can You Keep Untreated Rainwater For?

If you are using your stored rainwater for your plants then you can keep it indefinitely. Obviously, the cleaner you keep the water the better it will be for your plants, but it will not do them a significant amount of damage. 

However, if you are planning on using your collected rainwater for other purposes, such as for drinking water or for washing your clothes then you should not keep it longer than one week if it is untreated. If it is kept any length of time beyond this then it will cause damage. Drinking untreated water that has been stored for a long time can make you very ill. 

But if the water is just for your plants then you can simply store it for as long a period as you need and then filter it before use. That way you can ensure that no bugs or algae will be fed to your plants, but beyond this, there is no risk to them.

You can either install a filter directly into the rain barrel or you can add one to the instrument of your choice: a watering can or a hose pipe. That way you are minimizing the amount of effort on your part whilst still ensuring that your plants are getting all of the nutrients that they need. 

Final Thoughts

Rainwater is a fantastic natural alternative to tap water when it comes to keeping your plants alive and healthy. By having a good setup to collect and store rainwater you will save yourself a lot of money in the long run, as well as do some good for the environment. Essentially, you are simply recycling the water.

The rainwater is naturally soft and contains some essential nutrients for your plants so by using this cheap alternative you are actually helping them to be healthier. However, if you are also using your rainwater for other things, such as drinking water, you should monitor the chemical levels very carefully.

For plant use only you can store the rainwater indefinitely. You can simply filter it before pumping it through the hose or before using a watering can. That way you can still ensure that your plants are getting clean water, even if it was from a rainstorm last year. 

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