Can You Use Washing Up Water on Plants?

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Washing up water, commonly called recycled or “grey” water, is effluent from washing dishes and clothes. This water can be used for toilet flushing, irrigation, and machinery cooling, but not drinking. This method can utilize 50% of residential wastewater.

Now the question that arises is, can it be used for watering plants? Let’s find out in this article.

But before that, let’s get a little more familiar with washing up water.


Background on Washing-Up Water

Goleta County, California, pioneered the distinction between gray and black water contamination levels. The local water district conservation office advocated for gray water for household use in the county due to this distinction.

The conservation office wrote to the Santa Barbara Board of Supervisors that gray water’s impurities were not severely contaminated with feces or urine, making it appropriate for filtering and reuse.

Properties of Washing-Up Water

Gray water—washing-up water—can help the environment. Phosphates in dishwashing detergents can fertilize the soil. This makes gray water ideal for reuse and conservation.

The Goleta County water conservation office convinced the Santa Barbara Board of Supervisors that gray water recycling is safe and effective. In 1992, 17 western states legalized gray water use.

This milestone advanced water conservation and highlighted the significance of alternative water sources.

Since then, water recycling and conservation—including washing-up water—have grown in popularity. Gray water lowers water scarcity and freshwater strain.

Gray water recycling systems can help conserve water as more people and towns go green.


Can You Use Washing Up Water on Plants?

During droughts, using “grey” water on plants can aid. The shower, bath, kitchen sink, and washing machine rinse water is grey water.

To protect your plants, use grey water carefully and follow the instructions.

Grey water quality matters. Grey water may include detergent residues. These contaminants may not harm your plants, but not all can withstand them. Planting soil and compost filter out these pollutants, thus it is ideal to make sure to not miss out on the same

Moreover, soap and detergent residues can benefit plants. These leftovers may nourish plants.

However, food plants like vegetables and fruits should not be treated with these chemicals. Unfiltered grey water with feces and urine can be harmful as well, thus, it is important to understand what kind of washing-up water can be used on plants.

How To Properly Use Washing-Up Water On Plants?

The best benefits from watering your plants with grey water can be achieved by the following steps:

  • It is advised that grey water be filtered to eliminate any solid particles or bigger debris before being used on plants. You can use a filtration system or a fine mesh to do this.
  • Make immediate use of grey water. Grey water that sits around for too long can develop a bacterial breeding ground, which can be harmful to plants. To prevent the growth of bacteria, grey water should be used within 24 hours of being collected.
  • If you have more grey water than you need, you may either put it to better use around the house or dispose of it in an environmentally responsible manner.
  • Don’t use it on plants with edible portions. Grey water is not safe for consumption. Thus, you won’t be putting your health at risk by consuming plants that have been exposed to unfiltered grey water.
  • Instead of spraying it on the plant’s leaves, grey water is better off applied directly to the soil. As a result, the leaves of the plant are less likely to become contaminated or damaged.


What Kind Of Washing-Up Water Should Not Be Used On Plants?

Not all washing-up water can water plants. Avoid using dishwater on edible plants if you’ve washed poultry or other infected items. Bacterial contamination causes this.

Bathwater, which may include soap residues or other toxic elements, should not be used on plants either.

If you have a vegetable garden, use dishwater on non-edible or non-water-contact plants. Thus, you can use water without endangering food crops.


What Are The Benefits Of Using Washing-Up Water On Plants?

Below is a detailed overview of the various benefits of using washing-up water on plants:

Nutrient-Rich Water

Washing-up water includes several plant-beneficial nutrients.

Dishwater contains residual food and detergent residue. These particles contain nitrogen, phosphorus, and potassium. Washing-up water can replenish these minerals for optimal plant growth.

Save Water

Washing-up water reuse on plants conserves water. We can reuse this water instead of dumping it.

This reduces water use and strain on natural water sources. This simple practice can help save our planet’s water.

Affordable Solution

Washing-up water is cheap plant care. Reusing washing-up water saves money and gives plants the nutrients they need. It saves money and cleans dishes and plants – win-win, right?

Enriching Soil

Washing-up water can nourish soil beyond its nutrients. Soapy residue improves soil moisture retention as a natural surfactant.

This reduces watering for plants that need continuous hydration.

Moreover, organic matter in water improves soil structure and fertility, making plant roots healthier.

Chemical Reduction

Reusing washing-up water on plants reduces chemical fertilizers and pesticides. Synthetic substances in plant care products can harm humans and the environment.

Natural alternatives like washing-up water reduce the usage of such pesticides, making plant care safer and more sustainable.


What Are The Cons Of Using Washing-Up Water On Plants?

Plant care goes beyond watering. Many gardeners and plant enthusiasts use greywater—washing-up water—to hydrate their plants. Washing-up water on plants may seem eco-friendly and convenient, but there are disadvantages.

Cleaning Agents

Chemicals and detergents in washing-up water pose a risk to plants – especially sudsy dishwashing soaps that contain phosphates, surfactants, and scents.

Using these compounds regularly can harm plants. Dish soap compounds can alter soil pH and fertility, causing plant stunting or death.

Salt Buildup

Washing-up water may cause soil salt accumulation. If a water softener is utilized, dishwater is salty.

As plants absorb soil water, salt builds and damages roots, reducing growth and output. This can permanently destroy the plant.

Nutrient Imbalance

Washing-up water as irrigation might cause soil nutrient imbalances. Greywater often has imbalanced nutrients from food particles or leftovers.

Greywater may not supply the right nutrients for plants. Detergents and chemicals can also hinder nutrient absorption, worsening the imbalance.

Microbial Contamination

Greywater can contain germs and bacteria, especially if stored for a long time. Microorganisms in this water may infect plants and cause diseases.

If greywater comes into direct touch with edible plant components, microbial contamination may pose a health risk. Before irrigation, washing-up water must be filtered and treated.

Residue Buildup

Washing-up water may leave residues on plant leaves and stems. Water detergents and chemicals can create a film on the leaves, making them look dull or greasy.

This residue can hinder photosynthesis and stunt plant growth. Residue attracts bugs and insects, further harming the plant.


How To Use Washing-Up Water On Plants?

Below we have listed two popular methods to use washing-up water on plants:

The DIY Bucket Method

Collecting grey water in buckets may not be the most efficient method, but it is a simple and cost-effective way to reuse non-potable water. To get started, all you need is a bucket and some determination. Consider these DIY ways to save grey water indoors:

  • Warm-up water: Place a jar beneath the faucet to collect cold water as it heats up. Water plants with this.
  • Kitchen sinks: Rinse veggies and dishes in a pan. Gardeners can reuse pan water.
  • Stovetop: Don’t drain water from steaming or boiling vegetables. Instead, let it cool and water hydrangeas.
  • Rinsing bottles: Pour wine or other bottles and rinse water onto thirsty plants before recycling.
  • Bathroom sinks and bathtubs: Collect water from regular tasks like washing hands and brushing teeth in buckets for gardening.
  • Showers: Catch water as it warms in a bucket. Water plants with this.
  • Air conditioner condensation: Run a hose from the spout to your garden plants. During hot summer days, move the hose to hydrate plants.
  • Leftover coffee: Pour leftover coffee onto acid-loving plants like azaleas or Phalaenopsis orchids. Coffee nutrients will aid them.
  • Bottled water: Instead of tossing leftover bottled water down the sink, water your plants.
  • Dog bowls: Instead of flushing excess water from a halfway-filled bowl, pour it into a container for outdoor usage.

Professional Grey Water Irrigation Systems

Professional greywater irrigation solutions are available if the bucket method is too laborious. Greywater Action, a collaborative initiative, reduces home water use and promotes sustainable water practices.

They create economical, low-tech household systems that use gravity to move grey water from the kitchen, bathroom, and laundry room to the garden. These systems let homeowners keep a backyard ecosystem with food, decorative gardens, and wildlife.

Greywater Action offers installation training and a list on its website to help homeowners find trained installers.

Is It Worth The Money?

Installing a greywater irrigation system may appear expensive, but the long-term benefits may make it worth it. Reducing water use can lower your water cost over time. The system will pay for itself over time, depending on your water usage.

Professional greywater systems provide drought insurance for your plants in addition to financial benefits. Imagine a drought-stricken neighborhood with water rationing and thirsty vegetation. A greywater system might help protect your plants from water scarcity.


Can You Use Rainwater For Plants?

Since tap water contains chemicals, rainwater can be used to water plants. Before using rainwater for plants, consider a few things.

First, roof or other surface rainfall may carry bird droppings, dust, or neighboring contaminants. Use a rain barrel or gutter system with a filter to collect rainwater from a clean surface to assure water purity.

Second, verify the pH before using rainwater for plants. Most plants like pH 6.0–7.0. To optimize plant pH, you may need to add lime or sulfur to rainfall.

Rainwater storage is another issue. Rainwater must be stored in food-grade barrels or tanks. Chemical containers can taint water and harm vegetation.

Covering rainwater storage containers prevents algae and mosquito breeding. A mesh screen or tight-fitting cover can keep trash out while letting water in.

Plants may use rainwater to save tap water. Water quality must be monitored routinely. Discoloration, odor, or sediment may indicate contamination, thus avoid applying it on plants.

In dry periods or if you have a large garden, rainwater may not be enough for your plants. To keep plants hydrated, mix rainwater with tap water.


How To Double The Benefits Of Washing Up Water On Plants?

To maximize washing-up water use, mulch, and compost can be added to your gardening practice.

Mulch Power

Mulch covers the soil to protect it. It insulates the soil and prevents evaporation. Mulching your garden beds retains washing-up water and reduces irrigation.

Start with a mulch that suits your plants and gardening demands. Wood chips, straw, and shredded leaves are good organic mulches because they break down and improve soil fertility.

Gravel and plastic sheeting can be used as mulches, however, they don’t improve soil health.

Mulch your plants with at least two to three inches. Blocking sunlight limits weed growth and water competition. Mulch prevents soil erosion during heavy rains.

Utilize Compost

Compost helps gardeners conserve water. Decomposing kitchen waste, yard debris, and plant clippings are all options that can be utilized as compost. It enhances soil structure, water retention, and plant nutrition.

Apply compost as mulch to the soil to maximize its use. Washing-up water will soak into the compost and reach the plant roots. This decreases runoff and evaporation.

Compost prevents soil compaction, letting water penetrate deeper. This boosts root growth and plant health. Over time, composting your vegetable beds will improve soil moisture retention.


How To Prevent Bacterial Growth In Washing-Up Water That Is To Be Used On Plants?

Water recyclers and sustainable gardeners may worry about bacterial development in washing-up water.

Plant health depends on preventing bacterial growth. Preventing bacterial development in washing-up water involves these steps:

Strain Water

Strain washing-up water before using it on plants. This will limit bacteria-feeding water nutrients.

Conserve Water

To prevent bacterial growth, properly store washing-up water for plants. Stagnant water can breed bacteria. Thus, water must be used within 24 hours following collection.

Clean Containers

Clean washing-up water containers regularly. Thoroughly clean containers with a mild detergent and scrub brush. Rinse before refilling.

Darken Storage Containers

Algae and bacteria thrive under sunlight. Store containers in a dark, shaded area to avoid this. This prevents algae and bacteria growth.

Black Paint Containers

Black storage containers also limit bacterial growth. Black absorbs heat and raises water temperature, inhibiting bacterial growth.

Natural Disinfectants

Natural disinfectants can reduce bacterial growth in washing-up water. Hydrogen peroxide and vinegar are antibacterial alternatives. If overused, these compounds can harm plants.

Rotate Water Sources

Rotating water sources prevents nutrient buildup in washing-up water. Use fresh water one day and washing-up water the next. Reducing nutrition will inhibit bacterial development.


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