Any advice on using rainwater?

I’m getting gutters installed soon and I’ll be using a rain barrel to catch a lot of it. I’m wondering if there’s anything that I’ll need to add to it in order to make it appropriate for my trees. Clearly they get rained on naturally, but are there any issues with rainwater being the only type of water that they get?


I have been using this for a few years to collect rainwater. I do nothing with the water. I just water.


If you are pulling from the downspouts, I’ve heard some people say you should discard the water from the first storm of the year (pulls up extra tar or whatnot from your roof).

Other than that, you might need to check the ph and adjust for that but that’s highly unlikely as rainwater is pretty good ph wise.


Ah, good point about the runoff from the roof.

Depending on your local conditions, a rain barrel could empty in less than a week of watering. It may be worth looking into rain water bladders with larger capacities. Get the largest you can reasonably afford :slight_smile:

1 Like

My yard is tiny :confused: :sob:

You can sneak them under the deck… if you have one, that is :slight_smile:

Lol, I wish. My house is up on stilts which is where the garage is located.

Man, that’s gonna limit the options… biggest tank you can reasonably afford, then.

Lol, perhaps some day.

The average rain water is around 5.7 ph. (I think it’s pretty standard round the world but it may be worth checking locally). So it’s good for most trees including azaleas. I empty and wash mine out during January to get rid of algae and sludge which accumulates. This year though, we’ve had so much rain I’ve simply half drained it about four times instead.

1 Like

I store about 1800 gal. of rainwater in 7 of those cube tanks. I just use it as it comes out of the tanks. Rainwater has so little nutrient in it that it does not promote much algal growth and I don’t have to filter it. I use it on all my tender trees and anything in a show pot because my regular tap water causes mineral buildup on the pot. Trees in training pots may get conditioned tap water when the rainy season ends. If you can get it rainwater is the best for any bonsai.

1 Like