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Is A Rusty Watering Can Bad For Plants?

Metallic tools for outdoor gardening have a penchant for getting rusty after a short while. The rust typically appears after the iron particles react with oxygen and moisture (water).

Among the metallic tools, something that gets rusty pretty fast is the watering can. You may be wondering whether a rusty can could be bad for your plants. We discuss this in-depth in this article. 

Does Rusty Water Hurt Your Plants?

Rusty water in moderate amounts has no side effects on plants because it’s insoluble in water.

On the flip side, rust could turn out to be beneficial since oxidized iron imparts red color to subsoils. The iron in soils is of great benefit to plants.

However, under very low soil pH or extreme acidity, the iron oxide could get soluble.  A build-up of iron resulting from watering your plants with iron-rich water could cause significant damage to them.

As a precaution, ensure that the rusty metallic containers or tools in your garden don’t contain or are used to carry toxic materials. The toxic materials could be anything ranging from paints, oil, or dissolving agents.


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That said, there should be no fuss about a rusty watering can. Your only worry should be about the bad appearance. 

What’s Best? A Plastic Can Or A Metallic Watering Can?

Watering cans sold in stores are usually made up of iron or plastic. Each material has its pros and cons.

Plastic cans are less expensive, lightweight, and easy to tote. And if the bad appearance of rust in metals is something you don’t cherish, the plastic can is likely to be more appealing for you.

On the other hand, metallic cans are heavy and expensive but durable. Their major problem is rusting, but you will find them lasting pretty long.


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Plastic cans have some downsides as well. Off-gassing is common in low-grade plastics, and this could contaminate your water and poison your edible plants.

However, high-quality food-grade plastic is less likely to develop this problem.

In a nutshell, both of the materials are pretty good. It all boils down to your preference vis-a-vis their pros and cons. 

Preventing Your Metallic Watering Can From Turning Rusty

A combination of water and oxygen is deadly to iron.  The two components combine with iron, leading to the formation of ferric oxide, which appears as brown corrosion on your metallic watering can.

To get rid of this reaction, create a galvanized surface by coating your metallic can with zinc. You could also paint your watering can with rust-proof enamel paint.

You could also buy painted or galvanized steel watering cans.

They are handy to avoid the rust eyesore in your watering cans since water and oxygen can’t reach the iron surface beneath the zinc layer or the enamel paint.


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Also, you avoid the risk of overdosing your plants with iron in case it becomes highly soluble. 


Rusty water isn’t bad for your plants. However, you want to check your soil pH to make sure it isn’t very low since it could lead to the build-up of iron. Iron build-up can prove quite damaging to your plants.

The other challenge with rusty watering cans is that they are an eyesore. That said, you can solve the problem by coating your metallic can with zinc or rust-proof enamel paint.

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