By Christina Curell, Water Quality Educator

All summer you have diligently maintained, calibrated and cleaned out your sprayer. Good winterizing and storage of your sprayer can ensure that when you pull it out of your shop next year it will function properly. Here are a few tips to make winterizing easy.


Prior to storing a sprayer for the winter it needs to be thoroughly rinsed of all pesticide residues. It is better to rinse the sprayer several times with a small amount of clean water than to fill it up only once. 

Once the inside of the tank is cleaned out, do not forget about the outside of the sprayer. The outside should be rinsed with clean water and if at all possible on an impervious surface and the rinsate collected. Always remember to read the label of the pesticide used and use appropriate personal protective equipment when cleaning.


Once you have the tank properly rinsed the next step is to decontaminate it. You can purchase commercial cleaning agents or you can clean your system with some common household products. For a chart of the product and amount that you should use consult Montana State University Extension bulletin “Maintenance, Cleaning and Storage of Ground Sprayers”. Remember to run the cleaning solution through the entire system, including agitation and return lines. Rinse clean water through the system after it has been thoroughly cleaned, opening up the nozzles and running the water until only clean water is coming out.


Now that your sprayer is rinsed and cleaned, carefully inspect the system, making note of any maintenance concerns and repairing them. Look at nozzles, screens, hoses, valves, pumps, boom, as well as the tank. Now is a good time to check for tank integrity. Consult this previous news release, “How to Check Poly Tank Condition Using Three Different Methods.” Now is also the time to make any modifications that you need to make. Please remember that even though the system has been cleaned, you still need to be cautious and wear all labeled personal protective equipment.


The final step is to properly store the system. Any removable parts should be removed to ensure that there is no damage during storage, such as nozzles, filters, tips, check valves, screens and pressure gauges. If at all possible, store these in an area that will not freeze. Clean filters with soapy water before storage. 

The last step is to circulate antifreeze throughout the system including the boom’s hoses. Cap the boom nozzles. One or two nozzles may need to be left open to ensure total circulation — remember to cap them when the system is filled, to make sure that antifreeze is in the entire system.

Your system is now ready for storage. If you have foam markers and flowmeters, don’t forget to clean these also. To clean them, follow the manufacturers suggestions.