Quick Answer: Winterizing lawn equipment means more than draining the mower’s tank. Every gas engine, mower, trimmer, blower, edger, needs its fuel system addressed within about 60 days of last use, either drained or treated with stabilizer, according to Oklahoma State University Extension. Battery-powered tools need the battery pulled out and stored at room temperature, away from heat and direct sunlight. Hoses and anything holding water need to be fully drained before the first hard freeze.
Every fall, someone drains the mower’s tank, runs it dry, and calls the job done. Then spring shows up and the trimmer won’t start, the blower’s fuel line is gummed shut with last year’s gas, and the edger’s battery has been sitting dead in a freezing shed since January. The mower gets all the attention because it’s the biggest, most expensive piece of equipment in the garage. Everything else that ran all summer needs the same care, just in different amounts and for different reasons.
When to Start Winterizing Your Lawn Equipment
The right time to start lines up with when you stop needing the equipment, not a date circled on a calendar. Once your lawn stops needing a weekly cut, which for most cool-season grass means overnight lows holding in the 40s, that’s your signal to start moving gear toward storage. Waiting for the actual first hard freeze cuts it closer than it needs to: a mower or trimmer with fuel still in the tank once temperatures are already below freezing is a worse starting position than one prepped two weeks earlier while it’s still workable outside.
This guide covers the equipment itself: mowers, trimmers, blowers, edgers, battery tools, and hoses. If you still need to handle the lawn side of fall prep, fertilizer timing, final mowing height, aeration, our guide to winterizing your lawn covers that separately.
Winterizing the Mower: The Fuel Question Everyone Gets Wrong
Drain the tank or add stabilizer and top it off: both work, and which one is right depends more on where you’re storing the mower than on which method sounds more thorough. Oklahoma State University Extension’s fact sheet on ethanol blends in small engines lays out the actual mechanism. Gasoline, ethanol-blended or not, shouldn’t sit in an engine for more than about 60 days without a stabilizer added. Past that window, the fuel starts breaking down and leaving gum and varnish behind in the carburetor. Ethanol adds a separate risk: it can absorb water out of the air, and once that water hits roughly half a percent of the fuel’s volume, it separates out and pools at the bottom of the tank, which is what causes the rust and clogging people usually blame on ethanol itself.
If you’re storing the mower in an attached garage, or anywhere a fuel smell or spill next to a furnace or water heater is a real concern, drain the tank fully and run the engine until it stops. If you’re storing it in a detached shed, adding stabilizer to a full tank and running the engine a few minutes to circulate it protects the fuel system just as well, without the hassle of siphoning gas out by hand.
Beyond fuel, the same three items apply every year: change the oil while the engine is still slightly warm so it drains cleanly, pull the blade to sharpen or replace it, and if the mower has a battery, disconnect and store it separately (see the battery section below, the same rules apply whether it’s starting a gas engine or running the whole mower). For the full step-by-step process on all of this, spark plug replacement, blade torque specs, exact storage prep, our dedicated guide to winterizing your lawn mower walks through it in more detail.
Trimmers, Blowers, and Edgers Need the Same Fuel Logic, Different Cleanup
The fuel rules above apply to any small gas engine sitting idle over winter, not just the mower. What changes from tool to tool is the cleanup, because each one traps debris somewhere different. A trimmer’s shield and head catch grass clippings that dry into a caked layer if you don’t scrape them out before storage. An edger’s blade sits low enough to pick up dirt and rock chips that dull it faster than mower blades wear. A blower, by comparison, usually just needs a wipe-down since it doesn’t have a cutting deck collecting debris the way the others do.
One detail worth knowing if your trimmer or blower runs on a 2-stroke engine: that fuel is pre-mixed with oil, and old 2-stroke mix separates faster than straight gasoline once it sits. If you mixed a batch specifically for this season and have leftover fuel, don’t carry it into spring assuming it’s still good, mix fresh next year instead of guessing. For all of these tools, disconnect the spark plug before you start cleaning, just as a safety step, and check the air filter while you’re in there since a clogged filter is one of the more common reasons small engines run rough after months in storage.
Do Battery-Powered Mowers and Trimmers Need Winterizing Too?
Yes, just not for fuel reasons. Battery-powered equipment skips the gasoline problem entirely, but the battery itself needs specific handling that a lot of storage advice skips over. PRISM Risk Management, which advises public agencies on equipment safety, recommends removing batteries from tools whenever they’re not in use, especially for storage, and keeping them in a cool, dry area at close to room temperature, away from direct sunlight, heat sources, and vehicles. Don’t stack batteries or store them loosely where the metal terminals could touch another metal surface.
Watch for signs that a battery has actually failed rather than just discharged. The U.S. Fire Administration lists cracking, bulging, popping or hissing sounds, visible gas venting, and a battery that feels warmer than it should as warning signs of thermal runaway, the chain reaction that can lead a damaged lithium-ion battery to catch fire. If you notice any of that, isolate the battery away from anything flammable and don’t put it in regular household trash. On the charging side, use only the charger made for that battery, and don’t leave it plugged in for days at a time once it’s full. None of this is likely to come up with a healthy battery stored properly. Just don’t assume a hot garage for four months is a neutral place to leave one.
Hoses, Sprayers, and Anything That Holds Water
Drain it completely before the first hard freeze, since trapped water expands as it freezes and can crack a hose, split a sprayer tank, or damage the fittings on either one. Disconnect hoses from the spigot, drain them by walking the length while coiling, and store them somewhere that doesn’t freeze if you can, a garage or basement is plenty. Leaving a hose connected to an outdoor spigot all winter, even a supposedly frost-free one, traps water in the fixture itself and is one of the more common causes of a cracked spigot discovered the following spring.
Backpack sprayers and pump sprayers need the same treatment: run clean water through the system to flush out whatever was last sprayed, then drain the tank and pump fully. A full irrigation or sprinkler system is a different scale of problem entirely. Clearing water out of buried lines requires a compressed-air blowout at the right pressure for your system, not something most homeowners have sitting in the garage. Our guide to winterizing a sprinkler system covers what the process involves if you want to attempt it yourself.
Where to Store Everything Over Winter
Dry and temperature-stable beats cold and drafty, for gas equipment and batteries alike. Keep gas-powered tools off bare concrete where possible, moisture wicks up through concrete and speeds up rust on the underside of decks and blades, a pallet, mat, or shelf is enough of a barrier. For batteries, an unheated shed that swings from well below freezing at night to warm in direct sun during the day is worse than a consistent, moderate space like a closet or insulated garage corner.
Climate changes the stakes more than the method. In northern states, an enclosed, insulated space matters more because equipment left in an uninsulated shed sits through months of hard freezes. In milder southern climates, freeze risk is lower, but moisture and pests, mice especially like the smell of leftover fuel and the shelter of an idle mower deck, are still a real concern even where it never drops below freezing.
Common Mistakes When Winterizing Lawn Equipment
Leaving a battery on the charger for the entire off-season is one of the quieter mistakes, since it feels like the safe choice but actually shortens battery life over time. Draining fuel partway and assuming “mostly empty” is good enough is another: a small amount of plain gasoline left sitting for months can still gum up a carburetor just as effectively as a full tank would.
Forgetting hoses and sprayers until after the first freeze already hit is a common one too, usually because equipment winterization gets treated as a single afternoon focused entirely on the mower. And storing batteries stacked in a bin together, rather than separated with terminals protected, is a habit that’s easy to fall into simply because it saves space.
DIY or Hire a Pro for Equipment Winterization?
Most of what’s covered here is realistic to do yourself in an afternoon with tools you probably already own: a wrench, a fuel can, stabilizer, and a clean rag. Where it gets harder is the one job that genuinely needs equipment most homeowners don’t have on hand: blowing out a sprinkler system requires a commercial-grade air compressor and knowing the right PSI for your specific setup, too little pressure won’t clear the lines, and too much can damage them.
If that’s the piece you’d rather not tackle yourself, LawnGuru connects you with local pros who handle sprinkler winterization with the right equipment for your system, while you focus on the mower, trimmer, and everything else sitting in the garage.
FAQ
Do lawn mowers need to be winterized?
Yes, even if you’re storing it somewhere dry and heated. Fuel left sitting for months degrades regardless of storage conditions, and oil left in the crankcase over winter carries moisture that can corrode internal parts. Skipping winterization doesn’t guarantee a problem, but it’s the main reason mowers fail to start on the first pull in spring.
Why won’t my lawn mower start after sitting all winter?
Old, gummed-up fuel is the most common cause by far, especially if the tank wasn’t drained or stabilized before storage. A fouled spark plug and a clogged air filter are the next two most likely culprits. Before assuming something’s seriously wrong, try fresh fuel, a new spark plug, and a clean or replaced air filter, in that order, since that combination solves the vast majority of spring no-start problems.
Is it bad to store a gas mower with a full tank of fuel?
Not if you’ve added a stabilizer and run the engine long enough to circulate it through the system. A full tank with stabilizer leaves less room for condensation to form than a partially empty one does. Storing a full, untreated tank for months is the version that causes problems, not a full tank on its own.
Do battery-powered mowers and trimmers need winterizing too?
Yes. There’s no fuel system to worry about, but the battery still needs specific care: it should come out of the tool and sit somewhere cool, dry, and close to room temperature rather than an unheated shed or a hot attached garage. Leaving it in extreme cold or heat for months shortens its lifespan even if it never fails outright.
