Water is water, right? Yes, but sometimes water contains things that you don’t want your houseplants getting.
Tap water will usually be fine and will get you through, but a good houseplant parent is looking for better than ‘fine’. So, what is the best water for houseplants?
Glad you asked, let’s take a look!
What Water Should I Use For My Houseplants?
Ok, there are several types of water you might use on your houseplants, based on where they come from.
And yes, they are all quite different. Some will actually harm your houseplants.
Let’s just look at each one and why it is either good or bad for your plants.
Tap water is the best starting point because it is what 99% of you will want to use. It is readily available and the minimum of fuss.
However, everyone has slightly different tap water.
Basically speaking there is hard tap water and soft tap water. If you live in an area that is supplied by water that filters through mineral-rich rocks before it gets sent to you then it will likely be hard. If you simply get water that runs off mountains into streams then it will likely be soft.
You can tell the difference by spraying some water on a window or glass shower screen and letting it dry. If there are lots of white marks on the screen then it’s probably hard water.
Your houseplants will normally be fine with either. So why did I mention it? Because sometimes, if you have really hard water, you might have a water softener. This artificially softens your water. But it is nothing like naturally soft water.
You cannot regularly use artificially softened water on your houseplants because it will contain a fair amount of sodium. Once in a blue moon is fine, but not regularly.
So, hard or soft water is fine, just not if you have a water softener.
Some plants, known as ericaceous plants, will suffer over time if you only give them hard tap water. These include ferns and African Violets.
Another consideration with tap water is that it will often contain chemicals such as chlorine and flouride that are added for cleanliness and health reasons (however controversial you might find this). Generally speaking, these are not helpful for your houseplants, although not life-threatening.
The simplest way to reduce these chemicals is to fill a big jug of water and leave it to sit for 24 hours. The chemicals with ‘off-gas’, meaning they will simply rise out of the water and into the air (in tiny amounts so don’t worry about your air now!).
Tap Water Summary:
- It is by far the easiest type of water to use for your plants.
- It will generally not be harmful unless you have a water softener (but you might also have a dedicated hard water tap).
- To remove some of the chemicals, filter the water or let it sit in a jug for 24 hours.
I was going to say that rainwater is your next best option, but actually it is the best option if you can easily collect it.
Collection is the only issue with rainwater. If you have a water butt, then I highly recommend you use that water for your houseplants. They will be very thankful to you.
Rainwater is basically the same as distilled water, but with all the highly beneficial, natural dirtiness and nutrients that it collects on its journey.
If you don’t think you have room for a water butt, consider a space-saving water butt combined with a water butt diverter. All you need is access to a gutter down-pipe so, theoretically, you could even have one on a balcony.
I don’t think you should go down the route of buying distilled water just to be avoiding tap water for your houseplants. The cost of that will add up significantly and, as we’ve seen, tap water isn’t that bad.
- Use rainwater for your houseplants if you can get it.
- Consider a space-saving water butt and water butt diverter if you don’t have much space.
Technically, filtered water is a part of the tap water category, but seeing as you can get filtered water from other sources, I thought it would be good as a separate category.
Filtered water is very similar to the water you get by letting tap water sit in a jug for a day. But cleaner.
It will have almost everything stripped out of it except for the pure water itself. This means it will not have any of the bad stuff (chlorine, mercury, etc), but will also not have any of the good stuff (copper, magnesium, organic compounds).
The fact it doesn’t have the good stuff is not a big problem, especially if you are being a good houseplant parent and repot your houseplants when necessary to refresh the soil. Combine this with the use of fertiliser in the growing season and filtered water is perfectly fine.
The downside is the cost. Even a simple jug filter adds up in replacement filter costs over time. I would certainly avoid using bottled water… it’s hundreds, if not thousands of times more expensive than tap water, not to mention the environmental cost.
But if you already drink filtered water yourself then the extra cost will be much reduced.
I have filtered water on tap because it’s good for both humans and plants. Ok, so I got it because its good for drinking water, the houseplants benefit as a bonus.
Filtered Water Summary:
- Filtered water is good for houseplants, as long as you follow good repotting and fertilising practices.
- It is a more costly way of watering your houseplants, but if you already use filtered water for yourself then it’s not so bad.
So, What Water Will You Use For Your Houseplants?
Ultimately, it will come down to what is easiest for you. Whether that is ease of getting something like a water butt or filter set up or ease of accessibility at any point in time.
I have a water butt and filtered water and I swap between the two (usually depending on whether it’s raining or not ☂️).
But, I also use the tap-water-in-a-jug-for-24-hours method as well as a bit of soft water if I’m really feeling lazy (🤫).
As long as the majority of what you use isn’t going to harm your houseplants in the long run then you’ll be fine.
If you can use rainwater, great! If you have no option but to use tap water, no problem, but try the water in a jug method.
What do you think you will use in the long term? Let me know in the comments!