Graywater and the garden

Laundry graywater is not the best thing for your grass. Lawns prefer acidic conditions and soap residue is alkaline. Plus for safety reasons, you are not allowed to apply graywater as a spray. Graywater systems must release water at least 2 inches below the surface. Graywater is best for trees, shrubs and closely grouped plants that are easy to reach without extensive piping.

All graywater emitters must be under 2 inches of cover. Cover your drip irrigation with approved mulch, rock, woodchips, or soil shields. A filter can prevent hair, lint, food, and other particles from clogging your emitters. Clean or back flush your filters regularly.

• Some filter systems can sense blockages and perform an automated backflush.
• Drip irrigation requires a pump, electronic controllers, and a back flow prevention device.
• Expert installation knowledge is important.  Graywater drip irrigation can be a costly addition to an existing system. They are best for new systems separate from existing irrigation systems. 
• Use irrigation tubing 1-inch in diameter for the main irrigation line. Use 1/2-inch tubing to move water from the main line to individual plants in lengths no longer than 2 feet.   Smaller tubing can lead to clogs. Larger tubing can cause uneven distribution. 
• Large wood chips in graywater basins can condition the water. Wood chips can balance the pH of graywater.
• Don’t install an irrigation zone uphill from your washer without a permitted pump system. Laundry to Landscape provides more detail. 
• Don’t plug or restrict the outflow of your 1-inch tubing at the furthest outlet of a zone.
• Ball valves are not the best for graywater systems. Debris and minerals in graywater can create clogs.

• Avoid human and pet contact to minimize health risk.
• Graywater is different from tap water. Understand it well and be smart with it.
• Your first choice for graywater should be ornamental trees, bushes, and flowers. Next are fruit trees. Lastly, graywater is for edibles that are neither leafy greens nor root crops. It is always best to water edibles with regular water. 
• Works best on plants that prefer alkaline conditions.

• Don’t use unfiltered graywater for drip irrigation.
• Don’t apply graywater as a spray. 
• Don’t wet leaves with graywater.
• Don't use for leafy greens and root edibles.
• Don't use on seedlings, recent transplants, or exotics.

• Add compost to your soil.
• Use mulch.
• Avoid using chemical pesticides or fertilizers.
• Use plant-friendly products in your home. Biodegradable soaps, and ph-balanced products promote soil health.
• Salts and chlorine bleach can harm soil and plants. Irrigate with rainwater or fresh water a few times a year to improve your soil.

• Frequent rain eliminates the need to water.
• Washing dirty diapers or anything with chemicals. Materials soaked with oils or chemicals.
• Someone has a communicable disease (e.g., staph infection, hepatitis).
• Using harsh cleaning or personal care products. These include salts, bleach, harsh cleaners, and chemical dyes.
• The water isn't draining well and you see pooling or runoff.
• Plants are getting too much water.

• Ornamental trees, shrubs, and bushes.
• Large annuals with edible fruits that grow well off the ground.
• Berry patches but never blueberries. Blueberries need acidic conditions.
• Flower beds where many plants are bunched together.
• Where possible, use fresh water on your edibles.

• Agapanthus
• Bermuda Grass
• Berries (except blueberries)
• Bougainvillea
• Fan & Date Palms
• Fescue (Tall & Red varieties)
• Fruit Trees
• Honeysuckle
• Ice Plants
• Oaks
• Oleander
• Rosemary
• Roses
• Ryegrass
• Wheatgrass

• Deciduous plants
• Deciduous trees
• Most annuals
• Some turf grasses

• Crape Myrtle
• Evergreens
• Holly
• Redwoods
• Star Jasmine

• Ash
• Avocado
• Azalea
• Begonias
• Bleeding Heart
• Blueberry
• Camellia
• Ferns
• Foxglove
• Gardenia
• Hibiscus
• Hydrangea
• Impatiens
• Oxalis (Wood Sorrel)
• Philodendron
• Primrose
• Rhododendron
• Violet
• Xylosma