Don't Do the Right Thing the Wrong Way

Mowing and weedeating grass is a common cause of wildfires during the spring and summer months as vegetation is managed to reduce wildfire risk. Firefighters refer to these ignitions as “doing the right thing the wrong way.” Use the right tools for the job at the right time of the day and take all necessary precautions. Lawnmowers are not designed for high weed mowing.

The safest way to mow or weedeat grass is to do it during the coolest part of the day, normally before 10 AM, with a person watching for a fire to start, and the ability to suppress a fire that starts. Windy conditions can dry grass out and rapidly spread a fire that starts. Never mow or weedeat when any of the following conditions exist:

1. Grass is dry to the touch
2. Air temperature is above 90 degrees
3. Relative humidity is below 30%

Mowing and weedeating caused wildfires are specifically caused by improper spark arresters, striking a rock with a metal blade, buildup of grass against moving parts (friction) or exhaust, refueling hot motors, and setting hot motors in dry grass.

• Ensure you have a spark arrestor. Modern equipment is equipped with a spark arrestor.  Watch this video for more information: Why I Don't Remove Muffler Spark Arrester Screens From 2 Cycle Equipment!
• Replace metal blade on weedeater with string. Do not use lawnmower to mow anything other than green grass. Use a high weed mower with string, like the one here.  
• Do no let cut grass build up on top of decks of mowers or weedeaters. Spinning shafts, and hot motors/exhaust can ignite cut grass that builds up.
• Let motors cool before refueling and refuel in areas without vegetation.
• Do not set hot motors/exhaust in vegetation.

References:

Equipment & Vehicle Use