Epsom Salts Can Hurt Soil

DEAR MS. H.E.: I have an injury that requires me to soak my foot nightly in a bucket of hot water with two cups of Epsom salts dissolved in it. I alternate this with a bucket of cold water - hot then cold then hot then cold. This is beginning to add up to quite a lot of water. Could I throw it on the garden or lawn? Will it turn my garden into a desert? What are Epsom salts, anyway?

DEAR READER: Epsom salts are closely related to witch hazel and cream of tartar - that is, all three belong to that phylum of household products whose names you've heard all your life and whose ingredients and purpose are a complete mystery.

Philip Dickey, toxic-substances expert at the Washington Toxics Coalition, says Epsom salts are any one of a number of magnesium salts (magnesium hydroxide, magnesium citrate, magnesium carbonate, etc.) and they tend to be fairly innocuous. (Note the box says you can take small quantities of them as a laxative.)

But can you throw the salted water into the garden or onto your lawn? Carl Elliott, Seattle Tilth co-coordinator, thinks it's a bad idea. (I always find it amazing when I ask an expert an obscure question and they know the answer! He was not making this up!) While your soil does need magnesium, Elliott says the ratio of magnesium to calcium is very important and easily gets out of whack. In balance, your soil's calcium-to-magnesium ratio should be something like 10 to 1. Throw a bucket of water with two cups of Epsom salts in it onto your soil every day, and you will upset that ratio pretty quickly.

Dickey had another suggestion. Why not reuse the water? Add ice cubes to the cold water bucket every time. Reheat the salted water on the stove. Poor it down the drain and start fresh every three days or when it starts to smell like old socks, whichever comes first.

If you are a fanatic conserver of water (I'm not suggesting you are, mind you, but you are reading my column, after all), you could dispose of the un-Epsom-salted water by using it to flush your toilet. Turn off the valve that controls water flow to the toilet and refill the tank from your bucket. While the occasional Epsom salt-water tankful would probably be fine, a steady diet of Epsom salts would probably leave deposits that could eventually clog your mechanism.

DEAR MS. H.E.: I have a question regarding your article on composting toilets. For centuries - and to this day - the Chinese have been using their "night soil" as fertilizer for their gardens. This has allowed them to grow fertile soil - or what organic gardeners refer to as "humus" - as well as wonderful organic produce. Why, as in your article and other pieces I have read about composting toilets, are we in this country so careful to warn people to use this wonderful by-product, humus, only on ornamentals and not edible plants? Is this just another of our urban puritanical neurotic tics, or is there a bona-fide reason?

DEAR READER: It pained me to have to write "you can spread this on your ornamentals" when, in fact, my father puts his compost on his vegetable garden, and so do many other people with composting toilets. Properly composted feces should not contain any pathogens that will make you sick. Clivus Multrum has a publication, "Health Testing," on this subject. Here is their short answer: "In a Clivus, disease-causing organisms . . . die because conditions are not favorable to their growth, and because they are consumed by the very active population of decomposer organisms . . . " Health officials, whose job it is to look at the bigger public health picture, are more cautious. Washington State Department of Health guidelines say that compost should not be used on root crops or low-growing vegetables, unless you spread it 12 months before planting. These are only guidelines. If you are satisfied that your compost is stable, i.e., thoroughly composted, you are free to spread it wherever you like. For more information, contact your local public health department.

Susan McGrath's column runs every two weeks in the Home/Real Estate section. Send questions and comments to: The Household Environmentalist, P.O. Box 70, Seattle, WA, 98111.