When the grass stops growing and the first frost rolls in, it’s tempting to park the mower in the garage and forget about it until spring. But a little work now saves a lot of frustration later. Old gas gums up the carburetor, leftover clippings trap moisture and cause rust, and a neglected battery can be dead by April.
The good news is that winterizing a lawn mower usually takes an hour or two and a few basic supplies. The best time is right after your last mow, before the first hard frost. Here, we’ll cover winterizing gas push mowers, riding mowers, zero-turns, and electric mowers, so yours is ready for the first mow of spring.
Short on time? Here’s the process at a glance. Each step is explained in detail below.
Riding mowers and zero-turns need a few extra steps, and electric mowers skip the fuel, oil, air filter, and spark plug steps. See How to Winterize Riding, Zero-Turn, and Electric Mowers.
A few basic supplies are all you really need. Gather them before you start, and the job goes quickly.
Cleaning and blade care:
Fuel and engine (gas mowers):
Battery and extras:
Electric mower? You just need the cleaning supplies and your battery charger.
| What should you put in a lawn mower for winter? Fuel stabilizer and fresh oil. Stabilizer keeps gas from breaking down, and fresh oil keeps old, acidic oil out of the engine all winter. |
Gas mowers need the most prep, so work through these steps in order. The fuel step needs the engine running, so it comes first. Riding mowers and zero-turns follow the same steps, with a few differences covered in the next section.
Old fuel is one of the most common causes of hard starts in spring. Gas starts breaking down within a month or so, leaving varnish that clogs the carburetor. Ethanol in most gas also attracts moisture, which can corrode the fuel system.
Can you leave gas in a lawn mower over winter? Yes, as long as it’s treated with fuel stabilizer. Choose one of these three options:
| Option | How to do it | Best for |
| Stabilize a full tank | Fill the tank almost to the top with fresh gas, add stabilizer, and run the engine for 5 to 10 minutes. A full tank limits condensation. | Riding mowers, zero-turns, and mowers you may need for late leaf cleanup |
| Run it dry | Add stabilizer, run the engine for a few minutes, then let it cool. Siphon out the leftover gas, and run the mower until it stalls. | Walk-behind mowers |
| Use ethanol-free canned fuel | Drain the tank or run it dry, add canned fuel, and run the engine for a few minutes. It costs more but stays stable longer. | The longest protection |
Check your owner’s manual first, since recommendations vary by manufacturer. Always work outdoors, and keep gas away from sparks and open flames.
Turn the mower off, pull the rubber boot off the spark plug, and tuck the wire away. This keeps the engine from starting by accident while you work near the blade.
Old oil contains acids that can corrode the engine over winter. The engine is still warm from Step 1, which helps the oil drain, but let it cool for a few minutes first.
Take the used oil to a recycling center or another location that accepts it.
Clippings and dirt hold moisture against the metal, which leads to rust.
Keep water away from the engine and air filter.
A sharp blade cuts cleanly and eases the strain on your engine.
Replace any blade that’s bent, cracked, or deeply nicked.
A clogged air filter makes the engine work harder and burn fuel less efficiently. Remove the filter cover and check the filter:
Wipe out the filter housing before putting in the clean or new air filter.
Remove the plug, and replace it if it’s cracked, heavily carbon-coated, or worn. Check a new plug’s gap against your owner’s manual.
For extra protection, spray fogging oil into the spark plug hole, and slowly pull the starter cord a few times to coat the cylinder. Reinstall the plug, but leave the wire disconnected until spring.
Electric-start push mowers have a battery. Care for it the same way as a riding mower battery, covered in the next section.
Using zero ethanol gas throughout the year eliminates the need to use a winterizing agent like Sta-bil along with other year-long benefits. Zero ethanol gas also maintains a lower operating temperature and reduces corrosive damage to plastic, rubber and fiberglass components.
Pete Lombardo, Blain’s Farm & Fleet Divisional Services Manager
Once these steps are done, your mower is ready for storage. Jump to How to Store a Lawn Mower for Winter for where and how to park it until spring.
Riding mowers and zero-turns follow the gas mower steps above, with a few changes and extras. Good news for electric mower owners: yours takes the least work of all, since you can skip the fuel, oil, air filter, and spark plug steps. Just remove the battery or unplug the mower before you start. Here’s what’s different for each:
| Riding Mower or Zero-Turn | Electric Mower | |
| Fuel and oil | A stabilized full tank is usually best. Change the oil, and the filter if equipped. | None |
| Deck cleaning | Don’t tip it. Raise the deck, use the wash port, or remove the deck following your manual. | Scrape, then wipe with a damp cloth. Don’t hose it unless your manual says it’s safe. |
| Blade | Remove the deck or lift the mower safely to sharpen it | Follow Step 5 |
| Lubrication | Grease the deck spindles, front wheels, and steering fittings | Lubricate the wheels and height adjustment levers |
| Tires and belts | Inflate tires to the pressure in your owner’s manual. Replace cracked or frayed belts and learn how belt dressing extends belt life. | None |
| Battery | Lead-acid. See the steps below. | Lithium-ion. See the steps below. |
Zero-turn owners should also check the hydraulic system for leaks. On corded electric mowers, replace any damaged power cord before spring.
The battery is one of the most common reasons a riding mower won’t start in spring. A discharged lead-acid battery can even freeze and crack, so make sure to:
In spring, reconnect the positive cable first, then the negative.
If you’re wondering how to store an electric lawn mower for winter, the battery matters most. Lithium-ion batteries don’t like extreme temperatures or sitting fully charged or empty for months, so it’s important to:
Once your mower is prepped, the right storage spot keeps it that way. Moisture, temperature swings, and mice are the biggest threats, so here’s how to protect your mower until spring:
A few minutes spent on storage now means no rust, no nests, and no nasty surprises when the grass starts growing again.
A little prep now saves you from hard starts and costly repairs later, whatever kind of mower you own.
Rather leave it to the pros? If you bought your mower at Blain’s, our factory-trained technicians can give it a tune-up in the Small Engine Service Center at your local store. Find your nearest Blain’s Farm & Fleet to book an appointment.
Getting the rest of your equipment ready too? Check out our guide to winterizing your snow blower, trimmer, and other outdoor power equipment. |
It’s not recommended. Snow, rain, and freeze-thaw cycles speed up rust and can let water into the engine and fuel system. If you have no other option, park it under a carport or overhang, and use a waterproof, breathable cover. The storage tips above still apply, especially bringing the battery indoors. If outdoor storage is a regular problem, a small storage shed can protect your mower for years.
Often, yes. Many retailers discount lawn mowers in late fall and winter, when demand is lowest, to clear space for new models. If you’re thinking about an upgrade, the off-season can be a good time to shop. Check Blain’s Today’s Deals for current prices.
For more how-to guides like this one, check out our other Outdoor Equipment & Tools articles.
