Your Landscape Mulch Will GO UP IN SMOKE!

1. Your Landscape Mulch Will GO UP IN SMOKE! Larry G. Steward The Ohio State University ATI

3. BASIC FACTS ABOUT MULCH USE • Mulches are commonly applied in the landscape for a variety of reasons: • Aesthetic Appeal and Color • Organic Content • Nutrient Content • Moisture Modification • Temperature modification • Reduction of Weeds • Dust and Soil Stain Abatement

4. Original Research Premise • Most Commercial and Public Facilities no longer allow smoking inside • Only permitted location for smoking is outside 25 feet from facility entrances • These facilities still desire the beauty of landscaping including organic mulching • Consequently, is any mulching material Fire Ignition Resistant?

6. Mulches Used 1 to 2” Pine Bark Nuggets

7. Mulches Used 1” Pine Bark Nuggets

8. Mulches Used Ground Hardwood including Bark

10. Mulches Used Dyed Ground Scrap Wood

12. Mulches Used Composted Yard Waste

13. Mulches Used Pine Straw

14. Mulches Used Oat Straw

15. Mulches Used Cocoa Hulls

16. Mulches Used Ground Cypress

17. Mulches Used Dyed Ground Tires

18. Mulches Used Brick Chips

19. Mulches Used Turf Grass

20. Three Ignition Tests • Discarded burning cigarettes • Wooden matches • Propane torch

21. Ignition Tests • Discarded Burning Cigarettes • Two times- Immediately after applying mulch and one year later • Three cigarettes to each mulch-each a different brand • Preliminary Findings • Ignition varies to type and brand • Ignition varies to period of time mulch has been place

22. Ignition Tests • Match Ignition • One test with three wooden matches to each mulch sample • Six months after mulch installed • Preliminary Findings • Most all mulches will ignite with this form of ignition • Some may not continue to burn after match is extinquished

23. Propane Torch Fifteen seconds applied to each mulch sample then torch removed Test done one year after installation of mulch Preliminary Results Surprisingly even some of the organic mulches would not ignite Ignition Tests

24. Ignition Results 1 Balance of mulches did not ignite

25. Ignition Results 2

26. Ignition smoldered and burned down into mulch

27. Same Happened with Compost

32. Ignition Results 3

33. Ignition Results Additional • Match ignition of Rubber Chipped Mulch occurred every time in later demonstrations along with the Dyed Shredded Hardwood Mulch • Fire in Chipped Rubber Mulch • Gives off toxic fumes, • Cannot be extinguished with water in fact water spreads the flames • Extinguished by beating out with a shovel

35. Ignition Results 3 Continued

36. Ignition Results 3 • This compared to the sod rating of 2.13 and the brick chips rating of 1.13 • 1 was equal to no flame at the end of the 15 seconds and 7 had to be extinguished after 1 minute following exposure to flame

37. What Did We Prove? • Water in mulch will slow ignition • Age and decomposition of mulch will increase ignition probability • Temperature of igniter can affect ignition • Exposure time to igniter even at lower temperatures will increase ignition • Certain organic mulches CAN be used near smoking locations

38. OUR IGNITION RESULTS • OAT STRAW VERY HIGH • PINE STRAW VERY HIGH • GROUND RUBBER TIRES (DYED) VERY HIGH • SHREDDED PINE BARK, CYPRESS, • or HARDWOOD-- HIGH * • GROUND DYED PALLETS VERY HIGH* • YARD COMPOST MEDIUM* • PINE BARK CHUNKS-TWO SIZES LOW • TURF VERY LOW • COCOA HULLS VERY LOW • BRICK CHIPS NONE

39. RESULTS* • THE THREE NOTED WERE FOUND TO SMOLDER AND BURN WITHOUT FLAME FOR A PERIOD OF TIME WHEN AGED FOR A YEAR. • THEREFORE, IF NEW MULCH WERE COVERED OVER OLD MULCH, IGNITION OF NEW MULCH COULD OCCUR WHEN IGNITION TEMPERATURE IS REACHED. NO MATTER HOW LONG TIME HAS PASSED. • This NOT by spontaneous combustion

40. Conclusion One • In those locations where lit smoking materials are discarded, the following mulches should NOT be used: • Ground recycled pallets • Composted yard waste • Shredded pine bark • Oat straw • Shredded cypress • Ground recycled tires

41. FLAMMABILITY OF MULCH • Recent research on four common Florida mulches on flammability was done by Dr. Wayne Zipperer, et al; U. S. Forest Service, Southern Research Station, Gainesville, Florida • Highest Temperatures Results were on Pine Straw and Large Pine Bark, next was Small Pine Bark and Lowest Temperature registered on Cypress Mulch

42. Conclusion Two • Where there is a chance of a Firewise Landscape/Wildfire Interface, the following mulches should NOT be used: • Decorative ground rubber • Pine straw • Oat straw • Shredded hardwood bark • Ground recycled pallets

43. Under Decks

45. Around Possible “’’Ladder” Trees

46. Mulch and Fire • The Potential for Burning of the Mulch Needs to be a Landscaping Consideration: • When Selecting Mulch for a Public or Private Landscape • What the Environmental Conditions are for the Area—Dry or Wet • Relationship to surrounding wild areas that have potential for wildfire • Structure material in close proximity to mulch

47. Mulch and Fire • It has not been demonstrated that Spontaneous Combustion starts Landscape Mulch Fires due to the little depth of mulch. • Fires are initiated and ignited by outside sources in the landscape.

48. Possible Spontaneous Combustion Location

49. Landscape Mulch Depth Not enough depth to build up heat if applied properly for self ignition-”Smoke” is merely steam from moisture in mulch

50. Relationship to the Wildfire Interface • Remember the Four Firewise Plant Zones • Zone 1—Structure foundation to 5 feet • Zone 2---5 feet to 10 feet from structure • Zone 3---10 feet to 30 feet from structure • Zone 4---Beyond 30 feet from structure(or 100 feet if uphill from wildfire source)