Guest post by London Nelson, Star Tribune designer

I am the first to admit that I ' not always the greenest gal around. I have good intentions, but I'm kind of lazy. I'm likely to throw out the moldy sour cream rather than wash and recycle the container. I know, I know, I'm trying to do better.

However, I am proud to report that I'm keeping our water supply cleaner and saving money by making my own laundry detergent.

About six months ago I was trolling the Facebook page of one of my more crunchy-granola friends. Robin was talking about her homemade laundry detergent and how it cleaned just as well as the store-bought stuff and was way less expensive. I didn't even know such a thing existed. I consider myself something of a pioneer woman (I use a spinning wheel and make my own root beer!), so I thought I'd give it a try..

Most of the recipes were laborious, involving grating and cooking soap and other ingredients until it becomes a gloppy, icky-looking concoction. I wasn't that interested until I found a simple formula for powdered detergent that I could make in a snap. The three ingredients cost about $7 and make enough for several batches.

Ingredients:
1 cup powdered Borax (I knew the stuff from my cloth-diaper washing days.)
1 cup Arm & Hammer Washing Soda (not the same as baking soda. I find it at Cub Foods.)
Regular-size bar of soap with no added moisturizer (I prefer Fels-Naptha Soap because it made specifically for laundry, but I have used Dr. Bronner's, too.)

Directions:
Dump the two powders in a bowl. Grate the soap by running it through the shredder of your food processor. (I have an old machine I use for this. But I think you could use your everyday one if you wash it well. After all, it's just soap.) Pour the soap shavings into the bowl. Change the processer from the shredding disc to the cutting blade. Pour everything back into the processor and buzz it until all the soap pieces are ground up fine.

I store my laundry detergent in an old yogurt container and use 2 tablespoons per load. The clothes come out nice and clean, smell fresh and I'm saving buckets of money.

For my a family of three, I make a batch of detergent about every three or four weeks. I have a conventional top-loading machine but a friend with a high-efficiency machine says it works great for her.

Do you have recipes for being clean and green?