Leaving a lawn mower outside might seem like a convenient shortcut for homeowners focused on yard maintenance. After all, mowing grass is a routine chore, and quick access to equipment saves time. But is exposing your lawn mower to the elements truly cost-effective or safe? The answer isn’t a simple yes or no — it depends on several critical factors, including climate, mower type, and long-term maintenance habits. In this comprehensive guide, we explore whether it’s wise to leave a lawn mower outside, the risks involved, and the best alternatives for preserving your investment. Whether you own a gas-powered, electric, or battery-operated mower, this article provides actionable advice to ensure your machine remains efficient, durable, and ready for the next mow.
Understanding Lawn Mower Storage Challenges
Lawn mowers are complex tools made of metal, plastic, electrical components, and in many cases, combustible fuel systems. These materials are not naturally resistant to all outdoor conditions. Whether your mower runs on gas, electricity, or batteries, prolonged exposure to sun, rain, and temperature fluctuations can significantly shorten its lifespan.
Why Outdoor Storage Is Risky
1. Exposure to Moisture and Rust
Water is one of the most damaging elements for lawn mowers. Rain, morning dew, and humid air can cause metal components like the blade, crankshaft, and chassis to rust. Once rust takes hold, it not only degrades performance but can also compromise safety. A rusted blade, for instance, may crack or break during operation.
2. UV Damage from Sunlight
The sun’s ultraviolet (UV) rays degrade plastics, rubber, and painted surfaces. Lawn mowers stored outside under direct sunlight often experience brittle plastic housings, faded paint, and deteriorated wheel seals. These cosmetic damages may not stop the mower from working immediately but can lead to structural weaknesses over time.
3. Temperature Fluctuations
Extreme temperature changes — especially in regions with distinct seasons — stress the engine, battery, and fuel system. For example, rapid cooling and heating can cause condensation inside the fuel tank, leading to water contamination in gas-powered engines.
4. Pest Infestation
An uncovered mower can become a nesting site for rodents, insects, and spiders. Mice are particularly notorious for nesting in engine compartments during colder months, gnawing on wires and hoses. Insects such as wasps may deposit nests in sheltered undercarriage areas, posing risks to future users.
Types of Lawn Mowers and Their Weather Tolerance
Different lawn mowers react differently to outdoor environments. Understanding the distinctions helps determine whether brief or prolonged outdoor storage is feasible.
Gas-Powered Lawn Mowers
Gas mowers are the most common but also the most vulnerable to weather damage.
- Fuel System Breakdown: Moisture in the fuel tank leads to ethanol separation, gumming up carburetors and fuel lines.
- Oil Contamination: Water exposure can mix with engine oil, reducing lubrication effectiveness and increasing wear.
- Hard Starting Issues: After sitting outside, gas mowers may require extensive maintenance just to start.
While these mowers can be used in damp grass, they should never be stored outside long-term.
Electric Corded Mowers
Corded electric mowers rely on consistent power delivery through a cable. These models are sensitive to moisture.
Warning: While it’s safe to use a corded mower on wet grass under controlled conditions (following manufacturer safety protocols), storing it outside exposes the motor and electrical connectors to water, increasing the risk of short circuits or electrocution hazards.
Additionally, the cord itself can deteriorate due to UV exposure and physical wear from contact with the ground.
Battery-Powered (Cordless) Mowers
Modern battery-powered mowers offer greater flexibility, but their lithium-ion batteries are delicate.
Effects of Cold Weather on Battery Mowers
Storing a battery-powered mower in unheated outdoor sheds or garages during winter can damage the battery. Lithium-ion batteries operate best between 40°F (4°C) and 86°F (30°C). If stored below freezing for extended periods, the electrolyte solution can freeze, permanently reducing battery capacity.
Exposure to Moisture
Even though cordless mowers don’t have a fuel tank, their electronic motor and circuitry are still vulnerable to moisture. Water intrusion in the control panel can cause permanent failure and void warranties.
Short-Term vs. Long-Term Outdoor Storage
Deciding whether to leave your mower outside depends on how long it will remain exposed.
Short-Term Outdoor Storage (Overnight or a Few Days)
Leaving your mower outside overnight after mowing is generally acceptable — especially if covered by a tarp or protected under a covered patio. However, consistent nightly exposure adds up over time.
Best Practices for Short-Term Outdoor Storage:
– Tip the mower (if recommended by the manufacturer) to avoid oil leakage or spark plug fouling.
– Store on a flat surface to prevent fuel from spilling.
– Use a breathable mower cover (not a plastic tarp) to prevent moisture buildup.
Long-Term Outdoor Storage (Several Weeks or Seasons)
Long-term outdoor storage without protection is strongly discouraged. Over months, even minimal exposure accumulates damage that could render the mower unusable.
Before storing any mower outside for an extended period — such as during the off-season — seasonal preparation is essential.
Seasonal Maintenance Before Storing a Mower Outside
If you must store your lawn mower outside temporarily or lack indoor space, follow these steps to reduce damage:
1. Clean the Mower Thoroughly
Before storage, clean grass clippings, dirt, and debris from the deck, wheels, and undercarriage. Organic material retains moisture and promotes rust.
How to Clean Your Mower:
– Run the mower after mowing to clear loose debris.
– Use a garden hose (avoid direct water spray on engine or electrical parts).
– Scrape off clumped grass with a putty knife.
– Dry completely with a microfiber cloth before storing.
2. Drain or Stabilize the Fuel (Gas Mowers)
Old gasoline breaks down in 30–60 days, forming varnish that can clog carburetors.
Option A: Drain the Fuel
Empty the gas tank completely. Run the engine until it stalls to burn off remaining fuel in the lines.
Option B: Use Fuel Stabilizer
Add a fuel stabilizer to the tank and run the engine for 5 minutes to circulate treated gas through the system. This method preserves fuel integrity for up to 12 months.
3. Remove and Store the Battery or Spark Plug (When Applicable)
For cordless mowers, remove the battery and store it indoors at room temperature. For gas mowers, consider removing the spark plug to prevent moisture buildup in the combustion chamber.
4. Change the Oil and Inspect the Air Filter
Old oil contains acids and moisture that corrode internal engine parts. Drain and replace with fresh oil during pre-storage maintenance. Likewise, replace a dirty air filter to prevent clogs.
5. Sharpen and Balance the Blade
A dull blade strains the engine and tears grass instead of cutting cleanly. While not directly storage-related, sharpening before storage ensures the mower is ready for use when needed.
Proper Protection: Covering Your Lawn Mower Outdoors
If you must leave your lawn mower outside, proper covering is a must. But not all covers are created equal.
Choosing the Right Lawn Mower Cover
A quality cover should:
– Be made of breathable, waterproof fabric (e.g., polyester with PVC coating).
– Fit snugly to prevent flapping and water ingress.
– Include ventilation to minimize condensation.
Avoid Plastic Tarps: While cheap and available, plastic tarps trap moisture underneath, creating a greenhouse effect that promotes mold, mildew, and rust.
Best Placement for Outdoor Storage
Even with a cover, placement matters.
- Elevated Surface: Store the mower on a wooden pallet or cement block to avoid ground moisture.
- Sheltered Area: Use a carport, covered porch, or lean-to to reduce direct rain and sun exposure.
- Well-Ventilated Spot: Avoid dark, enclosed outdoor sheds without airflow, which retain humidity.
Indoor Storage: The Best Long-Term Solution
For lasting lawn mower health, indoor storage is the ideal choice. Here’s why:
Garage Storage
The garage offers protection from weather and pests.
Tips for Garage Storage:
– Keep the mower away from furnaces, water heaters, or other ignition sources — especially important for gas models.
– Elevate the mower on a shelf or stand to avoid floor dampness.
– Store gasoline in an approved container, not in the mower.
Shed Storage
A dry, lockable garden shed is another excellent option.
Ensure Your Shed Is Suitable:
– The roof and walls must be watertight.
– Install shelving or racks to keep equipment off the ground.
– Place a moisture absorber (like silica gel packets or a dehumidifier) to control humidity.
Basement or Utility Room Storage
These areas provide excellent climate control, but storing fuel-powered mowers indoors poses safety risks.
Important Safety Rule: Never store a gas-powered lawn mower — especially one with fuel in the tank — in a basement, living area, or where fumes could accumulate. Carbon monoxide and flammable vapors are serious hazards.
Battery-powered mowers, however, are safe to store in climate-controlled basements.
Weather and Climate: Regional Considerations
Your local climate plays a major role in determining how much risk is involved in outdoor storage.
Mild, Dry Climates (e.g., Southwest U.S.)
In arid zones with low rainfall and moderate temperatures, occasional outdoor storage is less damaging. However, UV exposure remains a concern, so covering is still advised.
Humid or Rainy Regions (e.g., Southeast U.S., Pacific Northwest)
High humidity and frequent rain drastically increase the risk of mold, rust, and engine failure. In these areas, long-term outdoor storage is strongly discouraged.
Areas with Harsh Winters (e.g., Midwest, Northeast U.S.)
Freezing temperatures and snow can crack casings, ruin batteries, and freeze residual water in engine parts. Mowers left outside in freezing climates often suffer irreparable damage, including blocked fuel lines and seized engines.
Myths About Lawn Mower Storage Debunked
Several common misconceptions lead homeowners to make poor storage decisions.
Myth 1: “It’s Just Outside the Back Door — It’s Fine”
Proximity to your house doesn’t protect the mower. If it’s not under cover, it’s still exposed to weather elements.
Myth 2: “My Mower Has Been Outside for Years — It Still Works”
Just because a mower runs doesn’t mean it’s performing optimally. Long-term deterioration reduces efficiency, increases fuel consumption, and shortens the machine’s overall life.
Myth 3: “Covering It with a Tarp is Enough”
As mentioned earlier, plastic tarps can trap moisture. A proper breathable cover is essential.
Myth 4: “I Don’t Need to Winterize My Mower”
Winterizing is crucial for gas-powered mowers. Skipping this step leads to hard starts, poor performance, or complete engine failure in spring.
Cost of Neglect: What Happens When You Leave a Mower Outside?
Ignoring proper storage can lead to expensive consequences.
Potential Damages and Repairs
| Problem | Effect on Mower | Estimated Repair Cost |
|---|---|---|
| Rusted Blade | Poor cut quality, safety hazard, imbalance | $30–$75 (replacement) |
| Carburetor Clog | Engine won’t start or runs poorly | $100–$250 (cleaning or rebuild) |
| Fuel Tank Corrosion | Fuel leaks, engine contamination | $150–$400 (replacement) |
| Short Circuits (Electric Models) | Motor failure, no power | $200–$600 (motor repair/replacement) |
| Seized Engine | Engine won’t turn, requires overhaul | $300+ (often not cost-effective) |
Conclusion: Over time, the cost of repairs from outdoor exposure often exceeds the price of a quality mower cover or minor indoor storage adjustments.
Best Practices for Lawn Mower Storage: A Summary
To maximize the lifespan and performance of your lawn mower, follow these best practices:
Year-Round Storage Tips
- Always clean the mower after each use.
- Store indoors when possible, especially during off-seasons.
- Use manufacturer-recommended fuels and oils.
- Inspect cables, hoses, and blades regularly.
Pre-Storage Checklist
- Clean the mower thoroughly.
- Drain fuel or add stabilizer (gas mowers).
- Change engine oil and replace air filter.
- Remove battery or spark plug (as appropriate).
- Sharpen the blade.
- Apply a light coat of oil to metal surfaces to deter rust.
- Store in a dry, ventilated, pest-free area.
Alternatives When Space Is Limited
Many homeowners struggle with limited garage or shed space. Here are practical alternatives:
Wall-Mounted Storage Racks
Install heavy-duty wall hooks or vertical storage racks for hanging mowers. This keeps them off the ground and out of the way.
Covered Outdoor Mower Caddies
Specialized outdoor mower enclosures, such as lockable steel cabinets with roofs, provide weather protection and deter theft.
Shared Community Storage (HOA or Neighborhood)
Some planned communities offer shared tool sheds or storage lockers for homeowners.
Final Verdict: Can You Leave a Lawn Mower Outside?
The short answer is: you can, but you shouldn’t — especially long-term. While brief outdoor exposure is manageable with proper protection, consistent or seasonal outdoor storage significantly increases the risk of rust, mechanical failure, and safety hazards. The convenience of leaving the mower just outside your door quickly diminishes when faced with costly repairs, downtime, or replacement.
Investing in a secure, dry storage space — even a small corner of a garage or shed — pays dividends in mower longevity, performance, and safety. Combine that with routine seasonal maintenance, and your lawn mower will serve you reliably for many years. Remember: a well-maintained mower does more than cut grass — it saves time, money, and frustration.
Take care of your equipment, and it will take care of your lawn.
Is it safe to leave a lawn mower outside during the winter?
Leaving a lawn mower outside during winter is generally not recommended due to the damaging effects of cold temperatures, snow, ice, and moisture. Exposure to these elements can lead to rust on metal components, deterioration of the engine, and potential freezing of leftover fuel or oil, which can impair performance when you’re ready to use it again. Additionally, snow and ice can block air filters and create moisture build-up inside the engine, increasing the risk of corrosion.
If you must store your mower outside during winter, take protective measures such as covering it with a waterproof, breathable tarp and elevating it slightly to prevent water pooling underneath. Drain the fuel or use a fuel stabilizer to prevent gumming in the carburetor, and remove the battery if it’s a battery-powered model. Ideally, store the mower in a dry shed or garage to extend its lifespan and maintain optimal performance.
What are the main risks of storing a lawn mower outdoors?
Storing a lawn mower outside exposes it to various environmental risks, including rain, humidity, UV rays, and temperature fluctuations. Prolonged exposure to moisture can lead to rust and corrosion on the blade, deck, and engine parts, while UV radiation from sunlight can degrade plastic components and wiring insulation over time. These conditions not only reduce the mower’s aesthetic appeal but also its operational efficiency and longevity.
Pests such as mice, spiders, and insects may also take refuge in an unmoved mower, nesting in the air filter, under the deck, or within wiring, which can cause damage when you restart the machine. Additionally, temperature changes can cause condensation inside the engine and fuel system, leading to water contamination in the fuel tank and potential starting issues. These combined risks make outdoor storage less than ideal without proper protective steps.
Can covering a lawn mower protect it when stored outside?
Using a high-quality, waterproof cover can significantly improve the protection of a lawn mower stored outside. A proper cover shields the mower from rain, snow, dust, and UV rays, helping to minimize rust and plastic degradation. It’s essential to choose a breathable cover to allow moisture to escape, preventing condensation from building up underneath, which could otherwise lead to mold or corrosion.
However, a cover alone isn’t enough for long-term protection. Ensure the mower is clean and dry before covering it, as trapped grass clippings and moisture accelerate rust and attract pests. Secure the cover tightly to prevent it from blowing off in wind, and consider using a cover specifically designed for lawn mowers to ensure a snug fit. For best results, combine covering with other storage practices like fuel stabilization and blade maintenance.
Should I drain the fuel before storing a lawn mower outside?
Yes, draining the fuel or treating it with a stabilizer is a crucial step before storing a lawn mower outside, especially for extended periods. Untreated gasoline can break down over time, forming gum and varnish that clog the carburetor and fuel lines, leading to difficulty starting the engine. Ethanol-blended fuels, common in modern gasoline, are especially prone to absorbing moisture, which can further damage internal components.
To prevent fuel-related issues, you can either completely drain the tank and run the engine until it shuts off or add a fuel stabilizer and run the engine for a few minutes to distribute it through the system. If storing for more than a month, draining is often the safer choice. This step helps preserve engine integrity and ensures smoother starts when the mower is next used, especially after months of outdoor exposure.
How can I prevent rust on my lawn mower when storing it outside?
Preventing rust begins with keeping the mower clean and dry. After each use, remove grass clippings, dirt, and moisture from the deck, blade, and undercarriage, as trapped debris retains moisture and promotes corrosion. Applying a rust inhibitor or light coating of oil on metal parts, especially the blade, helps create a protective barrier. Regular maintenance such as sharpening and cleaning the blade reduces vulnerable areas where rust can begin.
Additionally, store the mower on a raised, flat surface like a wooden pallet to prevent direct contact with damp ground, and use a waterproof, breathable cover. In humid climates, including desiccant packs under the cover may help absorb excess moisture. If possible, store the mower with the air filter and spark plug facing upward to avoid oil leakage and water ingress. These preventive measures can greatly reduce rust risk during outdoor storage.
Is it better to store a lawn mower vertically or flat outside?
For most traditional push mowers, storing them flat on a level surface is the preferred method, especially outdoors. Storing the mower flat ensures that oil remains properly distributed in the crankcase and prevents leaks into the combustion chamber or air filter, which can occur if the mower is tipped improperly. It also offers greater stability, reducing the risk of the mower falling over and sustaining damage, particularly when stored outside in windy conditions.
However, some mowers are designed to be stored vertically, typically rear-wheel drive models with this feature in mind. Always consult your owner’s manual before storing your mower on its side or vertically. If vertical storage is approved, ensure the air filter and carburetor are positioned upward to avoid oil seepage. For general outdoor storage, flat positioning on a dry, elevated surface remains the safest and most effective approach.
What maintenance should I perform before storing a lawn mower outside?
Before storing a lawn mower outside, thorough maintenance is essential to protect its functionality. Start by cleaning the entire machine—remove grass clippings from the deck, wash the exterior, and clear debris from the cooling fins and air filter. Change the oil if your usage season was extensive, as old oil can contain contaminants that promote corrosion. Inspect and sharpen the blade, replacing it if there are significant nicks or cracks.
Next, address the fuel system by either draining the tank or adding a fuel stabilizer. Remove the spark plug, clean it, and store it in a safe place, or replace it if it’s worn. Check tire pressure and ensure all nuts and bolts are secure. Finally, lubricate any moving parts, like height adjustment levers, to prevent seizing. Completing these steps will significantly enhance the mower’s readiness for the next season and reduce the risk of damage during outdoor storage.