I've never dealt with them myself but I did find some suggestions:
It has been suggested that spraying plants with a 1:1 mixture of alcohol and water will kill spider mites on contact.
It came from this site: http://www.getridofthings.com/get-rid-of-spider-mites.htm
Good luck! My beans are about the only thing that may produce a little. I'd be devastated to lose them to a pest.
According to "The Organic Gardener's Guide to Natural Insect and Disease Control" (Rodale Garden Books, ed. Barbara W. Ellis and Fern Marshall Bradley):
"Eggs or adults overwinter in bark crevices or garden debris, emerging in early spring. Eggs hatch in 2-3 days, nymphs develop to adults in 7-10 days. many overlapping generations every season; reproduction continues all year in greenhouses.
"Spray fruit trees with dormant oil to kill overwintering eggs; in garden or greenhouse rinse plants with water and mist daily to suppress reproduction of mites; release predatory mites Metaseiulus occidentalis on fruit trees, Phytoseiulus persimilis or similar species on vegetables, strawberries, and flowers; spray insecticidal soap, pyrethrin , or neem; as a last resort, spray avermectins or rotenone."