Disinfecting garden tools can help ensure the long-term health of plants and vegetables. According to the University of Minnesota Extension, plant pathogens, including bacteria, fungi and viruses, cause diseases that can damage and even kill plants.These pathogens can be transferred to plants and infect them through bits of soil and plant debris that get stuck on common gardening tools, including shovels and pruners. Pathogens are microscopic and invisible to the naked eye,which is why even tools that appear clean may still contain harmful substances on their surfaces that can prove life-threatening to plants. Disinfecting tools at the appropriate time, such as when the tools are being stored in fall or before using them in spring or after using them to remove infected pla nts, can prevent the damage caused by invisible pathogens. Avoid using strictly bleach to disinfect garden tools, as the UME notes that bleach corrodes metal and can therefore render tools that require sharp edges ineffective. A homemade solution that’s nine parts water and one part bleach can be used to effectively clean shovels, spades and rakes.The Centers for Disease Control and Prevention notes that isopropyl alcohol (rubbing alcohol) in concentrations of 70 percent or more can effectively disinfect surfaces for bacteria,fungi and viruses. Such a solution can be used to disinfect hand pruners and other small hand tools.