Is Grey water Good For Vegetables? Garden Tips 2024

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We use a lot of water in our daily habits and it would be a shame to continually waste it. In this article, we’ll discuss what grey water is, if it is safe to use, and how to better conserve the water we need.

Is grey water good for vegetables? Grey water, such as leftover water from washing dishes or having a bath, can be used in your vegetable garden. It should be poured into the soil to allow it to filter better. You can also take further precautions against bacteria and pathogens by only using grey water on plants that don’t come into direct contact with the soil.

What is grey water?

Grey water is an all-encompassing term that involves water that was once used for a specific purpose. This includes water used for baths, showers, and washing dishes.

Basically, clean water is used for specific purposes, mainly washing, and once it is done with its purpose, it may still be useful.

Grey water is not water that was used for flushing toilets. This has been exposed to fecal matter, which means it needs to be treated in order for it to be used in other manners.  

Grey water vs blackwater, difference?        

While you use clean water to flush a toilet, once it has served its purpose, it becomes blackwater. Blackwater is a mixture of water, urine, and fecal matter that flows through sewage pipes.

The water that drains from your dishwasher can also be classified as blackwater as it comes into contact with grease and pathogens, which again necessitates it being treated in order to be useful again.

Grey water, on the other hand, is primarily leftover from cleaning. This can include shower water, bath water, and sink water after doing the dishes.

Grey water can be used without treatment; however, black water cannot be used unless it is treated. Most municipal governments treat blackwater to help it break down better so it can be re-introduced into the natural ecosystem.

Homeowners can use grey water for their own needs but they should be confident that there are no chemicals or dangerous contaminants in it. Furthermore, grey water should only be used for specific purposes, which we will touch on next.

Is grey water safe for garden use?

Yes, grey water can safely be used in your garden. However, you should use it in a specific manner.

There are different viewpoints on how safe grey water is for your garden. While grey water has been used for centuries, the soaps we use and the food we eat is more processed, which means more chemicals can leach into this water.

Furthermore, grey water that comes simply from you rinsing food or from collecting shower water as you wait for the temperature to warm up will be cleaner than sink water from washing dishes. You will need to decide how to clean your water.

Generally, it is safe to use grey water in your vegetable garden as long as you plan on cooking those vegetables. You may also want to only use grey water on crops that won’t come into contacts with the soil, such as tomatoes and peppers.

How to collect grey water

Perhaps the easiest and most common way to transport grey water to your garden is through the use of a bucket. You can use small or large containers, depending on how strong you are and how far you need to transport the water.

Stovetop pots

An easy bucket idea for grey water includes the water in pots that you use to boil vegetables or pasta. Instead of pouring that used water down the sink, take it out to the garden.

Bathroom sink

How often do you let the water run while waiting for it to warm up to wash your hands? By placing a bucket in your bathroom sink, you can collect the water, including the water you use to wash your hands, and then easily transfer it to your garden.

Kitchen sink

The kitchen sink is a veritable minefield for grey water. It helps if you have a double sink to put one bucket in, but you can improvise with just one sink, too.

Any time you rinse out a glass before putting it in the dishwasher or rinse vegetables before cooking do so over your grey water bucket.

If you only have a few dishes you want to wash by hand, fill your bucket with natural soap. Then, you can throw that bucket of dishwasher outside after you are done.


While this may not be the most efficient and you may have to contort your body a bit, keep a bucket in your shower. At a bare minimum, you can collect the water as it warms up and then move that bucket out of the way.

If you want to take things further, keep the bucket in the shower while you wash. This will collect even more water and it might be a wake-up to take shorter showers when you see just how much water is used.


It can be hard to collect bathwater simply because you need to dip your bucket in and carry it out, which can be a bit messy. However, before you pull the plug, think about all the uses this water has.

Bottled water

There are probably countless times when you drink most of a bottle of water and go to pour the rest down the drain. Instead of doing this, however, take that water and use it to water your houseplants.

Pet bowls

Pets need fresh, clean water, so you probably change their water every day. If there is still water left in their bowl, use it in your garden instead of pouring it down the sink.

Benefits of using grey water for vegetables

Contains nutrients

Plants need nutrients and what’s neat is that they can get many of these nutrients from grey water. The soap and organic matter that is mixed in with grey matter are quite beneficial to plants.

Phosphorous, nitrogen, calcium, and sulfur are just some of the nutrients in grey water. While the water won’t have high amounts of these nutrients, if you keep using grey water in your garden, the amount will increase.

Pest control

If you use grey water from washing your dishes or from bath water, there will be trace amounts of soap in the water. This soap clings to plant leaves but doesn’t damage them.

Pests, however, are repelled by soapy water. They will avoid plants that have grey water on them, which makes for a natural pest deterrent.

Considerations of using grey water for vegetables

Water the soil, not the plant

Whenever possible, pour grey water into the soil around your plants and not directly onto them. This will allow the water to filter through the soil so that when the roots find the water, it will be cleaner.

Use water right away

Stagnant grey water is more at risk of developing pathogens. This is especially true in the summer.

Always use grey water within an hour or two after collecting it. This way, it can get into the soil before bacteria form, which can contaminate your crops.

Use organic cleaning products

The fewer chemicals that are in grey water, the better your garden will adapt to it. What type of soap you use will increase or decrease the efficacy of grey water?

Whenever possible, use plant-based cleaning products. Look for cleaning soaps that are organic or that have as few ingredients as possible.

Other types of water you can use for watering your garden


Why not get water directly from nature? Any time you can collect rainwater and store it for future use, you will greatly help the planet.

You can purchase special rain collectors that have lids and spigots on them. You can also just place buckets of water out to collect rainwater.

Rainwater has natural minerals in it that help your garden. Plus, you know it is safe as rain naturally waters your garden as it falls.

Aquarium water

The next time you go to drain your fish tank, move the hose so it feeds directly into your garden. Fish tank water will have small amounts of fish waste, which can act as a natural fertilizer. Plus, fish tanks can be quite large, so this water should be harnessed, not wasted.

Can you install an irrigation system?

If you get tired of moving buckets of water from your home to your garden, there is an alternative. You can install a greywater irrigation system.

This can be as simple or as complex as you want it to be. For example, a simple system is tapping into your washing machine discharge pipe and creating a system where that grey water runs into your soil.


It’s amazing once we realize how much water we waste every day. Grey water from your shower, bathtub, and sinks can be used to water your lawn and garden. While it can take a bit of effort, you’ll be saving money and the environment.

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