While drought plagues some regions of the country, gardeners in other areas are dealing with excessive rainfall. All that moisture means a bumper crop of slugs devouring prized plants and turning the lawn into a slug-ridden mine field. If this sounds familiar, fire up the coffee maker and brew some high test. USDA researchers in Hilo, Hawaii, have found that caffeinated coffee kills or repels slugs and snails better than the commercial slug bait, metaldehyde. The higher the caffeine content, the better.
Even coffee grounds will repel slugs, but the liquid coffee appears to be more effective. It can be poured onto the soil as a protective barrier around plants. Unfortunately the coffee may harm beneficial insects as well, so keep it off the foliage where the good guys are likely to be feeding.