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How do I store a lawn mower for the winter?

Deal with the fuel first: add an alcohol-free stabilizer to a full tank and run the engine a few minutes, or run the tank dry. Then change the oil, disconnect the spark plug wire and clean the engine and deck, look after the battery if it has one, and park the mower covered in a dry place away from flame.

Free to ask. Local shops send quotes, and you pay only when you book one.

By Kasra Taheri, Founder, LoclisPublished

Researched and drafted with AI, then checked claim by claim against the sources listed below before it was published. Prices and rules change; the dates beside each source say when it was last checked.

Step by step

Read when to stop and call a pro, further down this page, before you start.

  1. Step 1: Treat or empty the fuel

    Either add an alcohol-free stabilizer to a full tank and run the engine a few minutes,[1] or empty the tank and run the engine until the carburetor is drained of fuel.[2]

  2. Step 2: Disconnect the spark plug wire

    Pull the plug lead off the spark plug before you clean or reach near the blade.[4]

  3. Step 3: Change the oil

    With the engine warm, drain and replace the oil, and the filter if it has one, then dispose of the old oil properly.[1][2]

  4. Step 4: Clean the engine and deck

    Remove grass and debris from the engine surface and under the deck, using a degreaser and warm water, not gasoline.[1][2]

  5. Step 5: Oil the cylinder

    If your engine manual allows it, put about a tablespoon of engine oil in the cylinder through the spark plug hole, turn the engine over, and refit the plug.[2]

  6. Step 6: Inspect and lubricate

    Look for worn or damaged parts, tighten loose fasteners, and lubricate grease fittings, joints and axles.[2]

  7. Step 7: Look after the battery

    Clean, charge and store the battery in a cool place, protected from direct cold.[2]

  8. Step 8: Store it covered and dry

    Park it in a clean, dry place away from flame and cover it.[2]

Fuel first, then the rest

The most important job is the fuel. Gas begins to degrade in as little as 30 days, which can clog the fuel system and leave a mower that will not start the next season.[1] So before you park the mower for winter, either treat the fuel in the tank or run the tank dry, then change the oil, clean the mower, and store it somewhere clean and dry.

A red Toro 22-inch walk-behind lawn mower with a Honda engine, standing on grass in front of a tan storage shed
Photo: Garylittlewood, CC BY-SA 4.0, via Wikimedia Commons

Two ways to handle the fuel

Manufacturers do not agree on one method, so check your own manual. The two common ones both work when done properly.

Treat it and leave it full. Briggs & Stratton says to top off the tank before storing, add an alcohol-free fuel stabilizer and ethanol treatment according to the package directions, then run the mower for a few minutes so the stabilized fuel circulates through the engine's fuel system.[1] A full tank also leaves less room for moisture to condense inside it.[1]

Run it dry. Husqvarna's storage steps say to empty the fuel tanks or add a fuel stabilizer, then start the engine and let it run until the carburetor is drained of fuel or the stabilizer has reached the carburetor.[2] Briggs & Stratton's note for anyone not using its fuel stabilizer, or running fuel that contains alcohol such as gasohol, is to remove all fuel from the tank and run the engine until it stops from lack of fuel.[1]

Why the fuel matters more than usual with ethanol blends: gasoline is not water soluble, but ethanol is, so it can pick up contaminants and deposit them inside the engine.[3] Penn State Extension adds that engines that are rarely or seasonally used, such as lawnmowers or chainsaws, are especially prone to difficulties.[3] A mower sits unused all winter, which is the worst case.

Whichever method you choose, keep fuel away from flame. Husqvarna warns: "Do not store an engine with fuel in the tank indoors or in poorly ventilated spaces where fuel vapor can come in contact with open flames, sparks, or a pilot light such as in a boiler, hot water tank, clothes dryer, etc."[2] If you drain fuel, drain it into an approved container outdoors, away from open flame or sources of ignition.[2] A shed or detached garage is a better home for a mower than a utility closet with a water heater.

Oil, plug and cleaning

Change the oil while the engine is still warm, and replace the oil filter if the mower has one.[1] Dispose of the old oil properly.[2]

Before you clean anything near the blade, disconnect the spark plug wire. Virginia Cooperative Extension's rotary mower safety guide says to disconnect the spark or electric plug before troubleshooting or repairing the mower.[4] With the spark plug lead removed from the engine, Briggs & Stratton says you can use a garden hose to wash away residual grass clippings.[1] Clean the engine surface of debris, chaff or grass.[1] Do not use gasoline for cleaning; Husqvarna says to use a degreaser and warm water.[2] Always check your own manual first, since some riding mower makers do not want the machine sprayed with water.

Husqvarna's storage list also includes a step some owners skip: remove the spark plug and pour about a tablespoon of engine oil into the cylinder, then turn over the engine so the oil is evenly distributed and refit the spark plug.[2] It coats the cylinder wall against rust over the winter. Check that your engine manual allows it.

Deck, battery and parking spot

Thoroughly clean the machine, especially under the mower deck. Husqvarna adds to touch up paint damage and spray a thin layer of oil on the underside of the deck to avoid corrosion.[2] Inspect for worn or damaged parts, tighten any loose nuts or screws, and lubricate all grease zerks, joints and axles.[2] This is also the best time to book a blade sharpening, so the mower is ready in spring; see how to sharpen mower blades.

A riding mower or any push mower with an electric start needs its battery looked after. Clean, charge, and store the battery in a cool place, but protect it from direct cold.[2] The full routine is in how to store a riding mower battery for winter.

Finally, store the machine in a clean, dry place and cover it for extra protection.[2] A breathable cover is better than a sealed plastic tarp, which can trap moisture against the metal.

What to do in spring

Check the oil level, fit a fresh spark plug if yours is worn, and check the air filter before the first start. If the mower does not start, the usual cause is old fuel in the carburetor; see how to tune up a lawn mower for the full routine.

Stop and call a pro if

  • Fuel is leaking. Husqvarna's manual says that if leaks occur in the fuel system, the engine must not be started until the problem has been resolved.[2]
  • You cannot get the fuel out. If the tank will not drain, the fuel line is cracked, or the shut-off valve sticks, a shop can drain and service the system.
  • The engine will not turn over after the cylinder oil step. Do not force it; stop and have it checked.
  • A safety switch or guard is damaged. Never disengage any safety switches or devices.[4]
  • You would rather hand it off. Many shops do a winter service that covers fuel, oil, blade and belts; see whether to take the mower to a shop each year and what servicing costs. Husqvarna notes that an annual check-up at an authorized service workshop is a good way to ensure that the machine performs its best the following season.[2]

Getting help in Virginia

Loclis has more lawn equipment answers and a list of local pros at lawn equipment repair.

When you are ready, describe the mower once and local repair shops quote it.

Common questions

Should I drain the gas from my mower for winter?
Either approach works if done properly. Briggs & Stratton says to fill the tank, add an alcohol-free stabilizer and run the engine a few minutes. Husqvarna says to empty the tank or add stabilizer, and run the engine until the carburetor is drained or stabilizer reaches it. Check your own manual for which one it prefers.
How long does gas last in a mower?
Briggs & Stratton says gas begins to degrade in as little as 30 days, which can clog the fuel system and stop the mower starting next season. Untreated fuel left in the tank all winter is a likely reason a mower will not start in spring.
Is it safe to store a mower with gas in it in the garage?
Husqvarna warns not to store an engine with fuel in the tank indoors or in poorly ventilated spaces where vapor can reach open flames, sparks or a pilot light, such as a boiler, hot water tank or clothes dryer. If a water heater is in your garage, drain the fuel outdoors into an approved container or store the mower in a shed.
Should I change the oil before or after winter?
Before. Briggs & Stratton says to change the oil while the engine is still warm, and the filter too if there is one.
Do I need to take the battery out of a riding mower?
Husqvarna says to remove the battery, clean and charge it, and store it in a cool place protected from direct cold.[^husqvarna] See the separate answer on storing a riding mower battery for winter.

Sources

  1. [1] Storing Your Mower & Outdoor Power Equipment, Briggs & Stratton. Checked October 28, 2026.
  2. [2] Operator Manual, zero-turn mower, Husqvarna. Checked October 28, 2026.
  3. [3] Fuel Ethanol: Hero or Villain?, Penn State Extension. Checked October 28, 2026.
  4. [4] Lawn Care: Rotary Mower Safety (BSE-42P), Virginia Cooperative Extension, Virginia Tech. Checked October 28, 2026.

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