Graywater from Washing Machines: Safe for Landscape Plants

UGA Soil Lab analysis of graywater (GAIN detergent, half cup) found sodium, boron, and pH levels safe for ornamental plants. SAR (sodium adsorption ratio) was well below problematic thresholds. Measured pH 6.4 and alkalinity 40 compare favorably to well water averages.

Caveats:

• Boron in first rinse may harm sensitive plants (peach, onion, barley)—but you wouldn't use graywater on edibles anyway.
• Never use graywater on vegetable gardens due to pathogen risk.

Bottom line: Use graywater freely on landscape plants. See Graywater data and interpretation.