Tap Water and Your Garden

by on March 5, 2012

UrbanFig: Rain Barrel

Rain Barrels like this one are inexpensive and a great way to collect safe water for your garden.


It might surprise you to learn that one of the most common questions we get about urban gardening has to do with water. While many new gardeners are worried about the dangers of over watering or under watering their precious plants, still more are concerned about the water itself – specifically tap water.

There has been a growing concern in recent years over the safety of drinking tap water and even to a lesser extent, using tap water to bathe or brush your teeth. It makes sense then that some might be wary of using that water on the vegetables and herbs in the urban gardens that will feed them and their families.

Is Tap Water Safe for My Garden?

In most areas, the biggest cause for concern with tap water in the garden is chlorine. Chlorine – the same stuff in bleach –  kills pathogens and bacteria and while that may be what you want inside, you definitely don’t want something to kill the beneficial fungi and bacteria that are keeping your garden soil alive and thriving.  That reason alone may be enough to send you running from tap water for good, but you don’t have to necessarily.

The best solution in this case is to allow chlorine to dissipate from the water before you use it in the garden. You can usually achieve this by filling your watering can or a large bucket the night before, and allowing it to sit. Much of the chlorine will evaporate in that timeframe yielding a much safer water for your garden.


Of course the best solution is to use what nature provides whenever you can. While that’s not always a possibility in some urban settings, if you have the ability to use a rain barrel for water collection, do it. Nothing could be better for your garden!

{ 3 comments… read them below or add one }

Beth Jones March 7, 2012 at 4:30 PM

I have always heard that about tap water… so my “system” of sorts has always been filling up my big, metal watering can overnight and letting it sit in the spring. Put up high on a shelf to try to help avoid any accidents with wild or stray animals. During the scorching part of summer it’s hard… you need water NOW. I will be happy when I get a rain barrel system system in place!


Harriette Jensen January 9, 2013 at 12:46 PM

The water here in Oakland CA does not contain chlorine. The water district has started using chloromine, which does not dissipate in the air. It is my understanding, however, that clay filters it out. If you have clay soil, that may mean that you don’t have to worry. However, what would you suggest for others?


Michael Nolan January 9, 2013 at 12:53 PM

Chloromine is a combination of Ammonia and Chlorine, and as you mention, it won’t evaporate into the air as chlorine alone will. Your best bet to remove chloromine is with a high quality Reverse Osmosis or carbon filter.


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