Common sense rules here water that you used for washing vegetables will be no problem whilst washing up water from a barbecue needs caution.
Can you use washing machine water for plants. Washing machine water can be used to water the plants in your yard and garden instead of being sent to the sewer drain. For each load of laundry you run per week plan on irrigating 1 to 2 fruit trees 3 to 4 berry bushes 3 to 4 edible vines and 6 to 8 smaller perennial plants such as roses lavender or artichokes per load. Garden 19 per cent.
This really is the greenest option. Wash in hot water if it worries you--just dont pour it directly on the garden. Do not use greywater on vegetables fruit herbs or anything you plan to eat.
Never re-use water from toilets washing nappies or kitchen water. If its untreated limit your use to water from the shower bath and washing machine preferably only the rinse water. If you choose to use environmentally safe detergent that is fine as well but I have used all sorts of detergents and have never had any issues.
This type of water is known as dark greywater because it has a higher concentration of chemicals fats and other organic matter that isnt good for your garden. The answer is yes you can use water from a dehumidifier in the washing machine. I would also be unhappy about washing up liquids - unless organic - leaching their chemical content into the water table as these chemicals are highly toxic to aquatic life.
Unlike the contaminated black water from your toilet and kitchen sink greywater is easier to purify. The first thing you need to do is identify the water you can use from around your home. Sink a plant pot into the soil and pour the grey water into it so that microorganisms in the soil can further break down any remaining substances.
It is also loaded with nutrients that can feed your plants. Assuming you dont use harsh laundry detergent or chlorine bleach in your washing machine a laundry-to-landscape system can be an effective method of. So care needs to be taken to do as MG and Dorjac do - eco-products in water for the garden.