Never Too Early to Plan for Late Fall-Early Winter Outdoor Burning

winter-time burn piles
Building these slash piles many weeks before burning allowed the materials to dry out and be almost fully consumed when eventually burned. Photo: U.S. Forest Service.

With fall weather just around the corner people are starting to think of when and how they will burn this year’s silviculture (forestry-related) debris.

In this article I will focus on outdoor burning under Washington State Department of Natural Resources (DNR) rules. The rules apply to burning silvicultural material (wood, branches, bark, etc., left after thinning, pruning or harvesting forest trees) on lands that are:

  • Under DNR wildfire jurisdiction (see insert below)
  • Outside of a designated Urban Growth Area (UGA).

Ten Tips for Success

Here are some tips to ensure you are successful and safe when burning silviculuture debris this fall and winter after temperatures cool and fire dangers recede.

  1. Know the rules – Visit DNR’s Outdoor Burning web page to see if you need a permit to burn. Not all outdoor fires require a permit. Whether or not you need a permit, be sure to call 1-800-323 BURN or check DNR’s fire danger web page before you burn. DNR monitors local fire dangers and air quality issues through the year and may need to restrict or shut down outdoor burning in some areas, even in winter.
  2. Locate the pile in a good place – Piles should be 10 to 20 feet away from trees. Larger slash piles may need to be further away from trees. If protecting your trees is a concern, make sure to burn on a calm day. Wind can easily push a fire’s heat sideways and scorch trees more than 20 feet away. Be aware of what is under your slash pile, too, because burning can damage soil as well as tree roots.
  3. Building tall piles are better – A taller pile is better because it often will burn cleaner and hotter. Just like building a campfire you want to form a pyramid of material. At that bottom of that pyramid you’ll need tinder and kindling to get the larger material above to burn. Needles and small twigs are excellent sources of tinder and kindling to get your slash pile burning efficiently.
  4. Start building piles in spring and summer – Building burn piles in the spring and summer allows them to dry out before fall. Dry material ignites easily and will burn cleaner and more completely.
  5. Cover piles before fall rains – When summer nears its end, cover between a quarter and a third of your slash pile so there will be a dry spot to ignite it. Pick the area you cover carefully; it should have enough dry, fine fuels to easily ignite. Tarps or plastic sold in large sheets make excellent slash pile covers. For a more economical solution, check with local lumber yards to see if they are giving away used lumber wraps — the materials lumber mills use to cover the loads of 2×4’s they ship to lumber yards and home improvement stores.
  6. Build a fuel break around your pile – Clear away all flammable debris for at least 24 inches around your slash pile to prevent the fire from spreading. If your burn is one that requires a permit, follow any special directions indicated on the permit.
  7. Burn with snow – If you live where it gets cold enough for snow to stick on the ground, wait until a couple of inches of snow have accumulated before igniting your pile. If you are not in snow country, burn after several good rains to insure that the ground and any nearby vegetation are moist.
  8. Burn in the fall – Fall or early winter are great times to burn because your material will be dryer than if you waited until spring. Fall burning also takes advantage of the approaching wet, cold winter weather that can help assure the fire stays out after the burn. Statistically, most wildfires caused by escaped outdoor burning occur in the spring, not late fall or early winter.
  9. Ignite your pile with a propane torch – A propane torch is a safe and efficient way to get piles ignited. Never, ever use gasoline to ignite a pile. To see what can happen if you use gasoline, visit www.youtube.com and type in “gas brush piles ignition” to see videos on the many things what can go wrong when you use gasoline to ignite slash piles. Now that you’re online, google “propane torch” for find places to buy a propane torch if you don’t already have one.
  10. Check your pile – Check your pile after you think it is out. Use a shovel to dig in the pile’s ashes to ensure that it is truly out. Numerous spring and summer wildfires linked to outdoor burning are started by slash piles that were burned the previous winter, some even with snow on the ground! What happens is that a pile may burn down and appear to go out but some of the material will get mixed with dirt underneath and smolder throughout winter and into spring. Then, with warmer weather, the ground dries out, the still-smoldering material finally gets exposed to air and nearby dry materials. The result? The next wildfire. No matter how sure you are that your wintertime slash pile burn is out, check the pile again — at last twice — when temperatures warm up in spring.

How do I know if my land is protected from wildfire by DNR? Look at your annual property tax statement. If it contains a charge for the Forest Fire Protection Assessment (FFPA) then your land is under DNR’s wildfire protection jurisdiction. Owners of private and state “forest land” pay this fee to help support DNR’s wildfire preparedness, education, training and other protection activities. FFPA rates are established in law by the legislature (RCW 76.04.610), and are assessed on the unimproved forested or partially forested parcels, excluding structures.


By Guy Gifford, landowner assistance forester & fire prevention and Firewise coordinator, Washington State Department of Natural Resources, Northeast Region, guy.gifford@dnr.wa.gov

Want answers to your questions about outdoor burning? Contact your nearest DNR Region Office, 8 a.m. to 4:30 p.m., Monday through Friday.