Is Dishwater Safe for Vegetable Gardens?

Small quantities of dish water can help water a vegetable garden.

Safe Applications

A small quantity of used dish water can supplement fresh water for garden vegetables such as tomatoes, peppers, corn and broccoli. Dish water used for this purpose should not contain grease or food particles if at all possible, and other forms of gray water such as bathtub water are safer.

Unsafe Applications

The UMass Extension does not recommend using dish water at all for root vegetables such as carrots, beets, potatoes, turnips and radishes. In addition, avoid getting dish water on the parts of vegetables that will be eaten. Dish water should never be used on seedlings.

Bottom Line

The safety of dish water in the vegetable garden depends on what is in the water and what vegetables are being watered. This Old House advises against using dish water in vegetable gardens at all, but the UMass Extension says it can be used in small quantities on some vegetables.

References

• UMass Green Info: Recycling Gray Water for Home Gardens
• This Old House: Gray Water and Vegetable Gardens