Why does my garden hose smell like rotten eggs? How to fix an odorous gardening issue

Watering the plants is many people's favorite gardening task. It's relaxing and meditative and helps your plants to stay at their healthiest.

However, sometimes that calming chore can turn pretty foul smelling. Occasionally, the water coming out our your hose can smell like rotten eggs.

I chatted with our gardening experts about why this happens and how to stop it. The good news is that it's almost always safe. The bad news is that it can be fairly expensive to fix.

Why does my garden hose smell like rotten eggs?

The 'rotten egg' smell is almost always due to hydrogen sulfide gas. This naturally occurring gas results from sulfate-consuming bacteria in your water source, whether it's a well, plumbing system, or groundwater. These bacteria excrete hydrogen sulfate, which smells like rotten eggs.

Another possible cause, but less likely at this time of the year, is rotting leaves in your water source. As they decay, they can make a rotten egg smell. This tends to happen in the fall, as there are more rotting leaves around.

It's incredibly rare, but a more serious contamination is from agriculture or animals. Agricultural runoff from a nearby farm can get into your water source, introducing a wide range of bacteria and chemicals. It's the least likely source, but if you get your water from a well, a dead animal could contaminate your water and create that egg smell.

Is it dangerous?

Gardening expert Drew Swainston told me that 'The smell is pretty foul, but it's not dangerous for your plants. In fact, it won't affect them at all.'

However, it's a terrible smell, so it might make watering a little less enjoyable.

Drew Swainston

Drew qualified as a journalist and wrote for many websites and publications, before studying for a horticulture qualification. He worked as a professional gardener for several years, specializing in kitchen gardening. He's now bringing his expertise and passion to Homes & Gardens as a member of our team. 

How can I stop my garden hose smelling like rotten eggs?

The best short-term fix for a garden hose smelling like eggs is to buy a filter for your outdoor faucet. Hydrogen sulfide gas is unstable and breaks down when aerated. A filter on your faucet can remove the hydrogen sulfide and therefore remove the smell. However, these filters don't last forever, so this isn't a long-term fix.

How do I prevent it happening in future?

The best long-term fix is to get your water tested by a professional. A pro can tell you exactly what the issue is by identifying the levels of hydrogen sulfide, manganese, and iron in your water. From there, they can treat your water source and likely install an air injection filter. These pump air into your water which breaks up the hydrogen sulfide and removes the smell, but they're pretty expensive and can be tricky to install if you don't know what you're doing.

If the smell is also in your house, it could be an issue with the manganese anode in your hot water heater. This can be hard to DIY, so it's another case where it's probably fastest and cheapest to call a plumber. However, most outdoor faucets aren't usually connected to hot water, so it's most likely an issue with the groundwater or the well.

Garden hose FAQ

How do I get rid of the plastic smell in a garden hose?

The best way to get rid of the plastic smell in a garden hose is to fill a bucket with a mix of baking soda and water. Leave the hose in the mixture of a day and it should remove the smell.

For more help with watering, take a look at our guide to fixing a garden hose, or our tips on maintaining a garden hose.