How to Winterize a Lawn Mower and Outdoor Power Equipment: 2026 Guide
Quick Reference
- Number one killer: old fuel. Drain the tank or add stabilizer before storage.
- Oil change: annual or every 50 hours; you do not have to change it right before storage.
- Battery-powered gear: bring lithium-ion batteries inside if temperatures drop below freezing.
- Timing rule: winterize after the last mow, before the first hard frost in your zone.
- Do not pressure-wash a mower deck. High-pressure water forces into places it should not.
- Chainsaw exception: keep it ready if you cut firewood or clear storm damage.
- Spark plug rule: disconnect before touching a blade or working around the deck.
When the last mowing of the season is done, it is tempting to wheel the mower into the shed and forget about it until April. Do that, and there is a decent chance the engine will not start in the spring. According to the Outdoor Power Equipment Institute, old fuel is the number one cause of small-engine failure in spring, and its position has not moved for two decades. This guide keeps every step from the Almanac winterizing file and adds a piece-by-piece checklist, a first-frost timing table by region, and answers to the seven questions readers ask most.
Why Winterize Lawn Mowers and Other Equipment?
Fuel is the number one reason to winterize a lawn mower and other outdoor power equipment. Gasoline that sits in a small engine’s gas tank begins to degrade in just a couple of months, and the ethanol in modern pump gas attracts moisture that separates from the gas over time. Not only will old fuel cause equipment to run with less power and efficiency, it can also gum up the internal parts of the engine, shortening its life and making it much harder to start.
Managing leftover fuel is not the only reason to winterize equipment. Cleaning off dirt and debris, preserving batteries, and applying lubricant to ward off rust are all important parts of preparing power yard tools for the off season.
What Types of Outdoor Power Equipment Do You Need to Winterize?
In short, winterize any outdoor yard equipment that runs on a gas engine. Whether the machine has a two-stroke or a four-stroke engine, the process is the same.
Battery-powered yard equipment does not require much winterization. However, store lithium-ion batteries indoors if you live in a climate that drops below freezing. Cold cells lose capacity fast and can crack in a sub-zero shed.
Drain or Stabilize the Fuel
The most important step in winterizing any gas-powered yard equipment is dealing with the gas left in the tank. There are two options: drain the fuel or stabilize it so it lasts the winter.
- If only a small amount of fuel is left in the tank, run the mower until it burns off all the fuel and the motor dies. Restart the engine a few times to fully empty the gas lines.
- If there is a significant amount of fuel left over, rather than waste it (and add unnecessary exhaust to the air), add fuel stabilizer instead. Add the stabilizer to the fuel tank per the manufacturer’s instructions, then run the mower for a minute or so to circulate the stabilizer through the fuel lines and the carburetor. Stabilized fuel can last up to two years.
To Change the Oil or Not to Change the Oil
Lawn mowers, rototillers, pressure washers, and other yard equipment with 4-stroke engines require periodic oil changes. That does not mean you have to change the oil before putting the machine in winter storage. Unlike gas, which degrades over a period of months, it takes oil longer to deteriorate while sitting.
Change the oil in a 4-stroke engine about once a year or after every 50 hours of use. So, if the oil still has some life left in it, there is no need to change it as part of your winterizing.
Oil-change schedules vary, and some engines never require an oil change. Check the manufacturer’s instructions to determine when to change the oil for your yard equipment.
How to Winterize Common Yard Equipment
Along with managing leftover gas, there are a few other tasks to complete when winterizing yard machines. These tasks vary by equipment.
Gas-Powered Lawn Mowers
After draining the gas lines, clean the mower deck. Start by disconnecting the spark plug to prevent the motor from accidentally starting while working around the blade. Use a leaf blower or compressed air to remove any debris or grass clippings that have collected on top of the mower.
Next, tip the mower on its side so you can reach the underside of the deck (make sure the gas tank is empty; gas can leak out even with the cap on). With the mower on its side, use a scraper to loosen and remove any dried grass clippings stuck to the deck’s underside.
Do not be tempted to use a pressure washer for cleaning. High pressure can force water into places that are not supposed to get wet, causing damage.
Lawn Tractors
Winterizing a lawn tractor is like winterizing a walk-behind mower with a few extra steps. After draining or stabilizing the fuel, clean the mowing deck. Again, disconnect the spark plug before working around the blade. Use a blower to remove any grass clippings that have collected on top of the deck.
If the mowing deck has a washout port, clean out the underside by connecting a garden hose to it and flushing out the clippings. Otherwise, use a riding-mower lift to raise the mower and reach the deck’s underside.
After cleaning the deck and parking the tractor in storage, remove the battery and store it in a cool, dry place so it does not discharge over the winter.
Rototillers
After dealing with leftover gas, turn your attention to the tiller’s tines. Remove any dried dirt stuck to the tines. A garden hose works; a pressure washer can damage the tiller.
Once clean, wipe the tines dry with a rag, then rub a little cooking oil or used engine oil on them to prevent rust while in storage.
Pressure Washer
Pressure washers differ from other outdoor equipment because they have a pump system to winterize. Before dealing with leftover gas in the engine and fuel tank, winterize the pump. Drain any detergent or water left in it to prevent freezing damage while it is in storage.
Flush the system by putting the pressure washer’s injection tube in a bucket of water and running the unit for a couple of minutes. Turn off the pressure washer, then disconnect all the attachments and drain the lines and the spray gun.
Finally, attach a can of pump saver to the pressure washer’s water inlet and run it through the line until you see the pump saver liquid coming out of the outlet.
Chainsaw
Unlike leaf blowers, string trimmers, and lawn mowers that only see seasonal use, a chainsaw may be needed over the winter for cutting firewood or clearing downed trees after a winter storm. If that is the case, keep the chainsaw in action. Otherwise, winterize it by draining or stabilizing the fuel and cleaning the chain.
Start by engaging the chain brake to keep it from starting up while you clean it. Next, pop off the side cover and remove the guide bar and chain from the chainsaw. Use a dry, clean paintbrush or compressed air to remove any debris that has accumulated behind the cover. Then use a scraper to clear out any sap or debris stuck in the groove around the bar.
Clean the chain by soaking it in a solution of ammonia and water for about 15 minutes. Rinse the chain, allow it to dry, then oil it with chain oil before reassembling the chainsaw.
String Trimmers
String trimmers have an air filter that keeps debris out of the engine. Over time the filter fills with dirt, choking the engine.
Remove the air-filter cover and brush off any grass that has accumulated on the filter. If the filter is still in good condition, place it back in the engine and reinstall the cover. If the filter is caked with dirt or damaged, replace it with a new one.
Leaf Blowers
Winterizing a leaf blower is very similar to winterizing a string trimmer. Open the air-filter cover on the engine, remove the air filter, and examine it. Remove any debris and replace the filter if it is in bad shape.
The 30-Minute Pre-Storage Checklist
This is the short version, boiled down from the OPEI winterization guide and Almanac reader letters. Every step matters; skipping any one is where next spring’s no-start starts.
- Fill the tank three-quarters and add stabilizer, or run the tank dry. Do not store a partly full untreated tank.
- Run the engine for one minute after adding stabilizer so it reaches the carburetor.
- Disconnect the spark plug wire before touching the blade or deck.
- Scrape and blow the deck; wipe the underside dry.
- Check the oil level and note the hours. Change if annual or 50-hour mark is past.
- Pull the battery on riding mowers and store it indoors on wood or plastic, not concrete.
- Sharpen or replace the blade before storage so it is ready in April.
- Coat exposed metal with a light film of oil to block rust.
- Cover with a breathable tarp, not plastic, so condensation can escape.
- Note the storage date in the maintenance log with the fuel treatment used.
When to Winterize: First-Frost Timing by Region
The right window is after the last mow but before the first hard frost. Waiting past a hard frost lets moisture condense inside the engine block, which cuts winter storage life. These are median first-frost dates from the National Weather Service. Check your ZIP for a local number.
An Almanac Rule for the Autumn Shed
Old New England groundskeepers wintered the mower on the day the sugar maples went bare. It is not far off. That is roughly the first hard frost, roughly the last mow, and roughly two weeks before the ground freezes solid. If the maples in the yard have dropped their last leaves and the goldenrod has gone to seed, the mower is ready for the shed.
The Almanac has been publishing an autumn chore list since the 1800s. The one line every generation kept was “put the tools away dry.” Wet steel in a cold shed is next April’s rust. If nothing else in this guide sticks, that line does.
Join the Discussion
We hope this guide showed you how to winterize lawn mowers and other outdoor equipment.
Any questions?
Share your experience and ask away in the comments section below.
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Frequently Asked Questions About Winterizing Yard Equipment
How do I winterize a lawn mower step by step?
Drain the fuel or add stabilizer and run the engine one minute, disconnect the spark plug, clean the deck top and underside without a pressure washer, check or change the oil, remove and store the battery indoors if the mower is a rider, sharpen the blade, and cover with a breathable tarp. Total time: about 30 minutes for a walk-behind, 45 for a rider.
Should I drain the gas or add stabilizer?
Either works. If less than a quarter-tank is left, run it dry: it is quicker and there is nothing to hold water. If more than a quarter-tank is left, add stabilizer and run the engine one minute so it reaches the carburetor. Stabilized fuel is good for up to two years. The wrong answer is the third one: leaving an untreated half-tank in the shed. That is where next spring’s no-start comes from.
Do I have to change the oil before storing my lawn mower?
No, unless the annual or 50-hour mark is past. Oil degrades slowly at rest. Check the level, top up if low, and note the date in a log so the change happens at the right hour count next season.
Can I store a lithium-ion battery in an unheated shed?
Not below freezing. Lithium-ion cells lose capacity fast in the cold and can be damaged permanently below 32 degrees F. Bring the battery inside to a heated basement or utility room, off concrete, and top up the charge to about 50 percent before storage.
When should I winterize my lawn mower?
After the last mow, before the first hard frost. In the Northeast and Midwest, that is usually the first two weeks of October. In the Southeast, late October or early November. On the Canadian Prairies, first week of September.
Do I have to winterize a battery-powered lawn mower?
Almost nothing. Clean the deck, remove the battery, and store the battery indoors. There is no fuel to manage and no carburetor to gum up. Manufacturer instructions still apply; some brands recommend a specific storage-charge level.
How do I keep my mower blade from rusting over the winter?
Wipe the blade dry after cleaning the deck, then rub a thin film of used engine oil or cooking oil across the top and bottom surfaces. Store on a shelf or hang from a wall bracket so nothing sweats onto it. Sharpen or replace before storage so it is ready to bolt on in April.
Tony Carrick
Tony Carrick is an expert writer in home improvement, lawn and garden, and technology who contributes to FarmersAlmanac.com as well as Popular Mechanics, BobVila.com, US News and World Report, Pro Tool Reviews, and Popular Science. He covers a wide range of products—from power tools to grills to coffee makers—in how-to articles, product reviews, and feature stories. When he's not writing, Tony can be found working on his next home improvement project at his home in North Carolina.
