How to Repurpose Used Laundry Graywater for Earth-Friendly Gardening

How to Repurpose Used Laundry Graywater for Earth-Friendly Gardening


Reusing laundry graywater is a sustainable way to conserve water while irrigating your garden. Graywater refers to gently used water from sinks, showers, washing machines, and other household sources. With some simple systems, I can capture laundry water before it goes down the drain and repurpose it to nurture my plants.

Benefits of Using Laundry Graywater

There are several advantages to collecting and reusing laundry graywater:

  • Saves fresh water: Repurposing graywater reduces the amount of fresh water needed to keep plants hydrated. This preserves our limited drinking water supplies.

  • Removes waste from sewer/septic: Diverting graywater stops it from entering sewers or septic tanks. This decreases strain on wastewater treatment facilities.

  • Nutrients for plants: Laundry detergent and dirt from clothes contain phosphorus, nitrogen, and other minerals that feed plants when released into the soil.

  • Less chemical fertilizer needed: The nutrients in graywater can replace some commercial fertilizers. This saves money and avoids chemicals leaching into groundwater.

Evaluating My Water Sources

Before setting up a laundry graywater system, I considered my household’s water supply and quality:

  • Water source – My home uses a private well for fresh water. Capturing graywater will help conserve my limited groundwater supply.

  • Laundry detergent – I use low-sodium, plant-safe detergents without bleaches, dyes, or toxic chemicals. This creates graywater suitable for gardening.

  • Water quality – My well water does not contain heavy metals, salts, or other contaminants that could accumulate in the soil from graywater. I tested it to confirm it was safe for plants.

Choosing a Basic Graywater System

Several options exist for collecting laundry graywater, ranging from simple to complex:

  • Laundry-to-landscape redirect: This easy DIY approach involves connecting a pipe or hose to drain water directly from the washing machine to outside. I went with this low-cost, low-maintenance method since my landscape is downhill from my laundry room.

  • Holding tank: Graywater can be stored in tanks or barrels and pumped to the garden later. More parts are required, along with space for a tank. This setup allows greater control over when and where to use the water.

  • Constructed wetland: A biological system uses gravity flow through filtration beds of sand, soil, and plants to clean graywater naturally. This requires more land area and maintenance but maximizes water treatment.

Setting Up My Laundry-to-Landscape System

With my site suitable for simple water diversion, I followed these steps to set up my laundry-to-landscape graywater system:

Materials Needed

  • Washing machine with pump and accessible drain connections
  • Garden hose, piping, hoses, and fittings
  • Screen filter to remove lint and debris
  • Signage and splitters for potable vs. graywater plumbing
  • Shovel, tools, and hardware

Installation Process

  1. Disconnected the drain hose from my washing machine and ensured the drain pump was functioning properly.

  2. Installed a diverter valve with one output going to the sewer and one to a garden hose hookup. This allows me to choose where to send water.

  3. Ran piping and hoses from the new hookup on my laundry room wall to my yard and garden beds. I made sure to bury and stabilize any connections.

  4. Added a screen filter to the line to catch lint and particles before the graywater reached the garden.

  5. Clearly labeled both the graywater and regular plumbing hookups to avoid confusion.

Using the System

With everything hooked up, I can now easily divert each load of laundry to irrigate my trees, flowers, and other outdoor vegetation. The plants seem to love their new water source! To use it safely, I follow these guidelines:

  • Only wash biodegradable, plant-safe products in loads I’ll reuse
  • Rotate graywater between plants and yards areas to avoid saturation
  • Ensure graywater doesn’t touch edible plant portions or pool on the surface
  • Watch for signs of overwatering like soggy soil or unhealthy plants
  • Divert graywater back to the sewer if the garden has enough moisture

Maximizing the Benefits

My simple laundry graywater system cost very little to implement but is already reducing my environmental footprint. To make the most of this setup:

  • I use plain laundry detergent without additives, opting for low-cost, low-waste products safe for the garden. Vinegar works great as a fabric softener!

  • I fill wash loads to capacity so all the water gets fully used by plants, rather than wasted down the drain.

  • In dry times, I hand-water plants directly with a bucket first, then turn on the graywater to help it soak in.

  • I alternate graywater between zones in my landscape based on which plants need it most. This prevents oversaturation.

  • I watch for problems like odors, bugs, or unhealthy plants, and switch the system off if issues arise.

With some simple observation and care, I’m confident my laundry-to-landscape graywater setup will continue providing eco-friendly irrigation for my garden! Let me know if you have any other tips for repurposing graywater.