Mater Gardener: Winter project: Cleaning garden tools & pots

Lower the risk for plant disease in next year’s garden. Turn on the heater in your garage and spend some time cleaning your garden tools and dreaming about next year’s beautiful flower gardens and bountiful vegetable gardens. Many plant pathogens can survive from one season to the next in infected plant debris, soil, or on tools, trellises, stakes, or pots that were used to grow plants.

Remove all soil and plant debris attached to tools, trellises, or old pots. Potting soil, annual plants, leaves and stems killed by frost can all be placed into a compost pile. Use a brush or hard stream of water to completely remove soil and other organic material.

Make a 10% solution of bleach (5.25% Sodium hypochlorite) by mixing one part bleach with 9 parts water. Dip or spray tools with the 10% bleach solution. This will kill fungi, bacteria, and viruses within seconds. Bleach can be very corrosive to metal, so bleach may not be a good choice for metal pruners and other cutting tools that require a sharp edge.

Lysol (.1% alkyl dimethylbenzyl ammonium saccharinate). Many different products carry the Lysol label so look in the bottom left corner for the active ingredient (see above). Research has shown that this formulation of Lysol will eliminate bacteria, fungi, and viruses from tools. Use the product as is. Do NOT dilute it in water. Lysol is not corrosive to metal and can be used to clean pruners and other cutting tools.

Studies have been done testing 3 concentrations of rubbing alcohol (70%, 90% and 99% isopropyl alcohol) for its ability to remove bacteria that cause fire blight transferred from a pruning tool. The tool was soaked in alcohol for 1, 3, and 5 minutes, and then used to cut into healthy apples. In all cases, the cutting tool spread the fire blight bacteria to 25% of the healthy apples. This shows that rubbing alcohol is not an effective disinfectant for bacterial diseases.

A disinfectant should be applied after all soil and plant material has been completely removed from the tool, pot, or other garden equipment. Apply the disinfectant to completely coat the surface of the equipment. Be sure to get the disinfectant into corners and tight spaces. Small pots, clips, or ties are most easily treated by dipping in a bucket of disinfectant. Wooden or bamboo stakes or trellises benefit from soaking in a large tub filled with the disinfectant to allow time for the solution to move into small pores and cracks common in natural materials. Large equipment like a garden tiller or a tall trellis can be sprayed. Use of a pressurized sprayer with a wand attachment can be useful in reaching the top of tall equipment or getting into tight spaces like the tines of a tiller.

Information from Michelle Grabowski, U of MN Extension Educator 2018