Two women smiling as they pour greywater from a watering can on plants in their garden

Gardening is incredibly eco-conscious, but many people face the dilemma of rising water bills and using too much fresh water. As a result, some gardeners are switching to greywater, or water repurposed from showers, sinks, dishwashers, and so on. 

However, there’s a lot you should know before adding greywater to your garden.

Throughout this article, we’ll discuss how you can use greywater in your garden, what you should avoid, and why it’s one of the best ways to water your plants.

Can Grey Water Be Used For Gardening?

You can use greywater for gardening if you ensure it doesn’t have too many additives or contaminants. Not only will various chemicals damage the soil, but they can also sear the roots and prevent your plants from growing. Therefore, opting for plant-safe cleaning solutions is always best if you intend to reuse the water.

When gardening with greywater, it’s important to avoid harsh detergents and strong chemicals. You can install a collection and dispensing system to automatically drip water into your garden. Another option is to collect the water from your sinks and showers with a bucket.

Here’s a list of five key points to know about gardening with greywater:

  1. Greywater provides numerous benefits you won’t find when using hose water – for example, hose water is much more expensive because the water is recycled. Furthermore, greywater often has a lot of additives removed (for instance, calcium) when it’s initially used. Both of these advantages make it optimal for gardening.
  2. Choose biodegradable soap, shampoo, and other cleaning products – anything you put in your garden will stay there for a long time. If you opt for biodegradable soaps and other cleaners, they’ll break down in the soil. You won’t have to worry about them preventing root growth, either.
  3. Steer clear of water with strong detergents (such as harsh laundry cleaners) – many people use strong laundry detergents to clean their clothes. Water with a lot of detergents will gunk up your garden and make it nearly impossible for plants to grow and beneficial bugs to thrive.
  4. It’s best to test a small patch of your garden before dumping all the water on the soil – while most greywater is perfectly fine for your garden, you should test a corner area with a couple of plants. Use about half a gallon of water, then look for signs of damage after a couple of days before proceeding with the rest of the garden.
  5. There are many ways to collect and use it – you can use numerous devices (buckets, hoses, drains, etc.). Greywater is easy to gather and even easier to use throughout your yard.

You can plant all sorts of fruits, herbs, vegetables, and other plants with greywater. However, some of them thrive much more than others. Below, we’ll provide a list of plants you can add to your garden if you use a lot of greywater from your home.

What Can I Plant For Use With Greywater?

You can plant almost anything with greywater, including trees, bushes, flowers, vines, etc. However, plants such as apples, lemons, grapes, blueberries, and many others thrive in it due to pH alterations. Remember that your water’s pH will inevitably influence the soil’s pH.

Greywater Action also states that the following plants work very well with greywater:

  • Raspberries
  • Rhubarb
  • Blackberries
  • Hops
Hops growing on a vine

Note: Don’t let the water touch the portion of the plant you intend to eat. While greywater is excellent for hydrating the soil, it’s not always safe for consumption.

Speaking of consumption, you should filter the water, whether or not you intend to eat the plants. Recycled water is usually safe to use right out of the sink or shower, but it’s better to be safe than sorry. 

Let’s dive into several ways to collect and filter greywater throughout your home.

How Do I Filter My Garden For Greywater?

To filter your greywater before pouring it into your garden, try one of these methods:

  • Collect the water in a bucket, then pour it over the cheesecloth to remove the particles – cheesecloth is a popular choice for water filtration because it removes extremely fine particles from it. It’s an excellent solution for those who use gritty exfoliants that they want to keep out of their garden.
  • Cut the water with a 1:1 ratio of hose water to dilute the soap and other additives – if you’re unsure whether or not your soaps are biodegradable, it’s a good idea to cut the greywater. Not only will you prevent them from harming the soil, but you’ll also ensure that the garden gets enough clean hydration.
  • Use a greywater collection system that automatically filters the water before it goes into the soil – these systems range from thin hoses that run from the laundry machine to your garden to high-end devices that pull greywater from every water source in your home, filter the water, and dispense it in the yard.
Diagram of a DIY Greywater System
Courtesy of ClimateBiz
  • Boil the greywater if you only use small amounts (such as balcony gardens in apartments) – this tried-and-true method ensures your garden won’t have unwanted particles, bacteria, and other contaminants. However, it’s important to note that boiling greywater won’t remove harsh chemicals.

Read on if you’re interested in learning the best processes for reusing greywater in your garden.

How Do You Use Greywater From House To Garden?

To use greywater from your house to your garden, follow these instructions:

  • Collect water in buckets when you use your sink or shower – you can also plug the shower or sink to ensure you get as much water as possible. Use a short tube or hose to siphon the water from the sink or tub into a bucket, then gently pour the bucket on the soil throughout your garden.
  • Water Wise Group suggests installing a greywater collection and dispensing system that connects to your bathtubs, laundry machines, and sinks – these high-end systems prevent you from having to do anything. They’re better than sprinklers because they use less energy, and you don’t have to worry about water collection.
  • If you choose the bucket method, let the water settle for a few hours to remove the heavy debris at the bottom. Then, place a thin mesh sheet over the bucket and pour the water through it to prevent the debris from getting into the soil. You can also pour it through a colander, though it won’t be as effective.

Never use greywater from the following sources in your home:

  • Toilets
  • Any water that touches feces, urine, or other bodily fluids
  • Water that’s mixed with harsh detergents that could harm the soil and the plants
  • Water sources plagued with fungal growth that could cause root rot

Greywater collection is pretty straightforward once you get the hang of it. Any water source that uses soft cleaners or nothing at all can often be repurposed. However, if you’re still worried about harming your garden, consider getting a sample of the water and testing it for calcium, phosphates, nitrates, and other contaminants.

A jar of dehumidified and greywater side-by-side on a table
A greywater sample on the left. Courtesy of Wikipedia.

Is It Ok To Put Washing-Up Water In The Garden?

It’s okay to put washing-up water in the garden if you don’t use harsh chemicals or have feces and other bodily fluids in the water. However, if you have babies or pets using the water source, avoid using it since it could be contaminated. Dirty water can harm plants and cause a hazardous environment for the soil.

Keep these things in mind before using washing water in the garden:

  • UC Davis warns that using water with food particles can attract various pests – while that doesn’t mean you should avoid kitchen greywater, it does mean removing large bits of food debris before pouring the water into the garden. It also means you might want to consider using an all-natural pesticide.
  • Avoid washing-up water if it has a lot of artificial dyes and scents – these additives might work wonders for your laundry, but they can cause long-lasting damage to your garden. Furthermore, many harsh chemicals will make herbs, veggies, and fruits inedible.
  • Make sure it doesn’t contain chunks or globs of soap – diluted soap is typically fine (as long as the ingredients aren’t harsh), but significant bits of soap and detergent will make it hard for the plants to grow. It can also make it challenging for the soil to evenly distribute the water to ensure optimal hydration.

Another option is to place a bucket in your shower when you’re soaking before using the soap, but not when applying or washing off the soap. This method ensures that none of the soap gets into the water.

Final Thoughts

While it’s important to avoid pouring dangerous chemicals into the soil, there are many ways to reuse greywater in your garden. Whether you prefer manual collection and pouring or an automatic drip-fed filtration system, there are ways for everyone to save money, energy, and plants with greywater.


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