End of Spraying Season Checklist

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About Tom Wolf (Nozzle_Guy)

Tom Wolf is based in Saskatoon, SK and has 33 years research experience in the spraying business. He obtained his BSA (1987) and M.Sc. (1991) in Plant Science at the University of Manitoba, and his Ph.D. (1996) in Agronomy from the Ohio State University. Tom focuses on practical advice that is research-based to improve the efficiency of producers.

See all posts by Tom Wolf (Nozzle_Guy).

It’s finally that time of year to put away the most-used piece of farm equipment, the sprayer. Winterizing is a necessary step, but also an opportunity to do a few extra things.


  1. Before you do anything, walk around the sprayer and note any telltale signs of liquid leaks. Once washed, the helpful dusty surfaces are gone and slow, chronic leaks may go unnoticed.
  2. Now it’s OK to clean and rinse the sprayer tank and wash the sprayer exterior.
  3. Drain any remaining water from the product and the rinse tanks. These remainders will cause unwanted dilution of the antifreeze. After you drain filter housings, inspect and clean filters.
  4. Choose your anti-freeze. Automotive anti-freeze works, but’s it’s toxic and you can’t spray or drain it on the ground. Liquid fertilizer is sometimes used, but it’s corrosive, crystallizes when cold, and is not recommended. The best product is RV Antifreeze. It’s friendly to rubber and plastic, considered non-toxic, and can protect down to the coldest temperatures. Some dealers carry specific sprayer antifreeze.
  5. Add between 25 and 50 gallons of antifreeze to the product tank, or if you have one, to the clean water tank. Most larger sprayers need at least 25 gallons just to prime the plumbing.
  6. If you have a rinse tank, start a normal rinse procedure. Run the product pump, drawing from the rinse tank and pushing the material through the wash down nozzles into the product tank. Once the rinse introduction is complete, an automatic rinse procedure may subsequently open various lines leading to the tank as it swirls the rinse solution through the tank. Familiarize yourself with the specifics of that process.
  7. If rinsing valves are manually controlled, once the antifreeze is in the product tank, run the pump, drawing from the tank and circulating back to the tank via agitation. If you have any other bypass lines, such as sparge, make sure the valve is opened. Run for two to three minutes.
  8. If you have an on-sprayer eductor system, run the antifreeze past it and activate the eductor wash process.
  9. Now, it’s time to push the antifreeze to the boom. Treat this like a boom cleaning, making sure the antifreeze gets to each nozzle body. If you have high- and low-flow options, open them to ensure the bypass gets the antifreeze.
  10. Activate one boom section at a time and ensure all nozzles have received the antifreeze. Open nozzle end caps and allow the antifreeze the push out the water that is trapped there. It helps if you first purge the system with compressed air, then you don’t need to wait for the clear water to gradually change colour as the antifreeze arrives.
  11. For extra points, rotate the nozzles through each position. As with cleaning or servicing, a remote-control boom section controller is invaluable here.
  12. Remember to activate the fence row nozzles if you have any. These usually have their own dedicated feed line coming off the outer boom section.
  13. If you filled your anti-freeze directly into the rinse tank, briefly open the rinse and product tank fill valves to allow anti-freeze to push out any water. Don’t forget the front fill line.
  14. It’s OK to leave any leftover antifreeze in the tank. Next spring, collect it for re-use in the fall. You’ll still need more but this saves you some.
  15. Don’t forget to also winterize your spray tender and any other transfer pumps.
  16. It’s always a good idea to grease fittings after equipment is washed, to displace any water that got in, and to lubricate other moving parts that should be protected from corrosion.

Inspecting and Reflecting

You’re going to be looking closely at a clean sprayer, and this is a good time to spend a few extra moments to ponder the big picture. But first:

  1. Inspect the full length of all hoses. Look for kinks, rubbing, small leaks, loose or defective clamps, valves, nozzle bodies. Tighten what’s loose, replace what’s worn.
  2. Check cabin air filter service interval. Most new sprayers have activated carbon filtration that requires regular replacement. Activated carbon starts deteriorating with any air contact, so if you get a new one, leave it wrapped in its plastic until you need it.
  3. Download or record sprayer performance data. How many engine and spraying hours? How many acres? How much water? A typical sprayer may calculate your acres per hour, but uses spraying hours only which paints a rosy picture. Do the calculation using gross engine hours to get a better idea of time lost to idling, transporting. Compare to previous year, perhaps set some goals.
  4. Check with the dealer to make sure you’ve got the latest controller software version. Many systems get an upgrade during the off-season, so check back in the spring.
  5. Remove the flow meter from the system and ensure it runs free. Do not use compressed air to run the impeller, this can ruin it. Simply blow on it and ensure it runs freely. This is an important part of the sprayer, so some people store it separately over winter. Did it provide accurate information?
  6. Top up the fuel tank to prevent condensation.
  7. Don’t forget to mouse-and bird-proof.


  1. Think back on the season. What went well? What went poorly? What repairs were needed? Which ones did you put off? Are you happy with your procedures for filling and cleaning? Did you hear or read about improvements that seem interesting? Reminisce by reading the notes you wrote on your cab windows.
  2. Make a list of the improvements that would address the main issues you came up with during your reflection. Is it time for a better filling setup? Do you need a whole tender system, or just an upgraded fill pump or a better inductor? Is it time to add a continuous rinse system?

Replacements and Improvements

  1. Some sprayer components simply wear out and need regular replacement. A rule of thumb for sprayer nozzles is about 30,000 acres for an average sprayer speed and boom width. But before you buy, make sure you know what you need. Were you happy with the spray performance? Did you have more drift than you wanted, or poor coverage? As our cropping systems change, we may need different nozzles to suit the purpose. Now is the time to think about that very coarse low-drift nozzle that would have allowed you to get the spray on before the rain that delayed you for 3 days. Or the higher volume spray that would have done a better job with desiccating the tall canola crop, speeding up harvest. Or the finer spray that works better with the contact products you need to manage resistance.
  2. Pumps can also wear. An impeller replacement can revitalize a centrifugal pump and give back more pressure and flow. Or a new pump with run-dry seals can avoid downtime from a pump failure in the middle of a good stretch of weather.
  3. We still see plastic boom lines on some sprayers. Replacing them with stainless steel eliminates warped lines and makes spray patterns more accurate, improves cleanout, and adds sparkle.
  4. A wider boom can dramatically increase productivity. After-market booms are available in 135′ and larger widths. Aluminum construction keeps them light, and corrosion-free.
  5. Pulse Width Modulation (PWM) can be retrofitted on any sprayer. This will offer improved sectional control resolution, turn compensation, and better droplet size control.
  6. Spot spraying can be added to any sprayer, and this will save 50 to 75% of pre-seed product use. In the case of WEEDit Quadro, these systems now come with stand-alone PWM that will work for general broadcast spraying in crop, with all the features mentioned above. Trimble offers the WeedSeeker II, it’s also feature rich but doesn’t offer PWM.
  7. Become part of a mesonet. Most crop imaging services and some agronomic service providers offer weather stations, and obtaining one can make you part of a large, high resolution network. Local monitoring of temperature, rainfall, and wind conditions improves spray decisions as well, and may even give you the ability to identify temperature inversions.

The sprayer will often be the first piece of equipment used in the spring. Preparing it for its next job starts now.