Post-fire tips from the Ecology Center

Wildfires swept through more than a quarter of Sonoma Valley, and many returning residents want to expedite the healing of their land but aren’t sure how to go about it.

The most important rule is to be safe. Assess the property carefully before acting. Watch out for potential hazards. Consult with professionals as appropriate.

Remember that the land has burned frequently over thousands of years. The native plants and animals are adapted to recover from fire. Be patient. Anticipate the wildflowers next spring!

• Do not enter the area where a building has burned, or handle the ashes of a burned building, without prior testing and protective gear: proper clothing, respirator, eye protection, gloves, etc. Vegetation ash is not toxic, but ash and debris from man-made materials may contain asbestos, heavy metals or other hazardous substances. Do not touch or breathe this material without consulting with county officials.
• Do not re-seed a burned site, not even with “native” seeds. Fire releases the native seeds stored in the soil, and those seeds will restore the land. Grasses are highly flammable, and a big flush of grass can attract pests. Many “native” or “wildflower” seed mixes contain species that are genetically inappropriate to our area and could be destructive invaders.
• Do not spread straw, hay, or use bales, unless you can guarantee they are free of seeds. Even material sold as weed-free is usually contaminated.
• Do not simply chip or remove all brush, branches and trees. Rather, use that material to prevent soil erosion (see below).
• Be cautious! Before reentering a burn site, first assess the property for hazards including toxic ash and debris, unstable structures, trees with burned-through trunks, power lines, and landslides or mudslides.
• Consult with county officials and obtain professional help in removing potentially toxic materials. Ideally, clean the site before rains wash toxic runoff into storm drains and waterways.
• Slow down soil movement, especially into waterways. Use logs, branches, small berms, sandbags, check dams, silt fencing, native plants or other features to slow runoff into nearby streams. Repair fire breaks so they do not channel runoff but blend in evenly with the slope of the land. Mulching is only modestly effective for reducing erosion, and can introduce weeds. Use only mulch with guaranteed seed-free material, such as chipper material from a known source, hydromulch without seed, or guaranteed straw.
• Have an ecologist or arborist assess the damage to vegetation before planting or seeding. Most trees and shrubs will recover on their own, and the land’s existing seed bank will push new growth in the winter. If you do seed, use only guaranteed locally native perennial species.
• Be suspicious of “weed-free” material for sale. Inspect it carefully yourself. • Be patient. These lands have recovered from wildfires countless times before. In most cases, once man-made debris and ash are removed from a burn site, the land will heal itself. It just needs time.

Information provided by Sonoma Ecology Center, North Bay Climate Adaptation Initiative, www.laspilitas.com, and www.sonomacounty.ca.gov. To learn more, contact the SEC [email protected].