Firescaping: Post-Fire Recovery for Your Landscape
After more than three weeks, some of California’s most devastating wildfires are nearly 100% contained, enabling authorities to lift all remaining evacuation orders and allow residents to return to their properties. As residents begin returning to their homes, it is important to remember that damage to your property isn’t always limited to the structures—your landscape can suffer significant harm as well. In this post, Douglas Kent, a landscape and fire-protected property design expert with 30 years of experience, shares 6 ways of helping you to restore and protect your outdoor space for the future.
Fairfield, California, USA. Photography from Trevor Bexon.
1. Minimize Traffic
Keep foot and equipment traffic off burnt landscapes. Activity on slopes will increase the likelihood of erosion by weakening a soil’s bonds, dislodging soil particles, and trampling just sprouted plants. Activity on flat ground can compact the soil and lower its water absorption rates, which increases runoff.
Informative sketch & graphic depiction courtesy Douglas Kent.
2. Leave the Mess
Do not clean your landscape—the debris on your injured site provides much needed protection. The charred remains of plants and garden features protect the landscape from wind and water erosion, slows sheeting water, and helps prevent the surviving seeds and plants from drying out. Do not remove debris until a restoration plan has been developed.
3. Drain Water
Drainage systems will be clogged with debris after a fire. Water skipping out of drains, such as swales, is a leading cause of erosion, fire or not. Roof gutters, street gutters, culverts, swales, infiltration and detention basins, small streams, and concrete waterways will need cleaning. This is the very first thing to do.
Malibu, California, USA post-fire. Photography from Brian van der Brug.
4. Divert Sheeting Water
The chances of topsoil loss dramatically rise if a landscape receives sheeting water from nearby features. Driveways, roadways, sidewalks, and parking lots are often designed to sheet their runoff to the landscape. If this is the case on your property, divert that runoff away from the landscape and towards the storm drain system.
Diverting devices include bales, check dams, diversion ditches, dry stacked walls, staked boards, and sandbags.
5. Watering
A recently burned landscape will absolutely need water, but there are two distinct types. The first immediate watering is aimed at breaking the soil’s repellency layer. This watering is light—no more than 1 gallon per 10 sq ft. The goal is to water only the top quarter inch of soil.
Once the repellency layer is broken, begin deeper waterings. The goal is to get the water 4 inches deep and encourage seeds, roots and surviving plants to sprout. Three to 5 gallons of water per 10 sq ft will be required. Water again only when the first 2 inches have dried.
Informative sketch & graphic depiction courtesy Douglas Kent.
6. Assess Your Risk of Topsoil Loss
Determining the levels of erosion risk not only helps prioritize recovery resources, but also helps determine the aggressiveness of your response. The erosion test below provides indicators to the likelihood of topsoil loss, but for an accurate analysis of risk consult a local Certified Professional Soil Erosion and Sediment Control Specialist (CPESC).
California, USA. A tree sprouts in the ashes of a forest fire.
a. Slope
A slope’s degree of incline has the greatest influence on its chances of producing erosion. The incline and length of a slope are two measurable factors. Although slopes have a higher risk of erosion, flat ground is susceptible too. Scorched and bare landscapes are easily compacted and prone to puddling and sheeting water, contributing to erosion elsewhere.
Steepness of Slope
o 1 Point: Between 0 -16%: Not Likely
o 2 Points: Between 17% - 34%: Low Likelihood
o 4 Points: Between 35% - 51%: Likely
o 8 Points: Between 52% - onward: Most Likely
Length of Slope
o 1 Point: 0 - 25 feet
o 2 Point: 26- 50 feet
o 4 Points: 51 - 100 feet
o 8 Points: 101 - 200 feet
b. Rain
How a burnt landscape reacts to storms depends on the amount of time between the fire and the first rain and the rain’s intensity and duration.
o 1 Point: A late autumn sprinkle with light to moderate storms through remaining season.
o 2 Points: Late autumn sprinkle with heavy winter downpour.
o 4 Points: No autumn rain and heavy winter downpour.
o 6 Points: Heavy early autumn and winter downpour.
c. Type and Density of Plants Burnt
This is a forest versus grasslands comparison. You are looking at two measures: the amount of debris littering the landscape and the amount of plants remaining that can resprout.
o 1 Point: Formerly densely forested landscapes. Trees had shrubs and possibly ground covers growing below them.
o 2 Points: Formerly a landscape with scattered trees and no understory shrubs, or a landscape with only shrubs and ground covers. Oak woodland and coastal scrub communities are examples.
o 3 Points: Formerly a grassy landscape with scattered perennials.
o 4 Points: Formerly a landscape with tough and difficult growing conditions. Plants are shallow rooted, sprawling and sparsely planted.
Informative sketches & graphic depiction courtesy Douglas Kent.
d. Type of Soil
The structure, density and size of a soil’s particles influence its likelihood of erosion. Clay soils are the least erodible, sand and gravel the most. But clay soils have other problems: they are much faster to produce runoff due to poor infiltration, and this leads to the washing of fine particles and the siltation of streams. Sand and gravel do not travel like clay.
• 1 Point: A soil dominant in clay that has silt, sand and/or organic matter.
• 2 Points: A sandy soil mixed with silt and organic matter.
• 3 Points: A clay soil with little or no organic matter.
• 6 Point: Sandy soils with little or no organic material. Loose and gravely rock.
e. Amount and Type of Activity
Activity by animals and humans has a large impact on chances of topsoil loss—the more activity, the more erosion. Tunneling animals, such as gophers and ground squirrels, are a threat to stability, more so if the fire has displaced their predators. Even walking on a burnt landscape can slow its recovery; trampling lowers germinations rates, redistributes seeds, and crushes new seedlings.
o 1 Point: Animals and people walking on the site.
o 3 Points: Storm drains and gutters clogged. Tunneling and browsing animals lack predators and their populations are large.
o 4 Points: An area that was cleared sometime before the fire and never replanted, allowing shallow rooted opportunists to grow.
o 6 Points: A barren landscape. Also, massive cuts into a hill and/or fill brought in on a slope.
f. Fire Intensity
A low temperature fire can cleanse and waken a dynamic landscape. A high temperature will do just the opposite—not much survives 2,000 degrees. Fire intensity not only affects a landscape’s rate of recovery, but also the amount of repellency a soil has. Hotter fires produce more repellency. This test assumes a fairly hot fire, slow recovery, and high repellency.
Offsite Water
Roadways, sidewalks, driveways and parking lots can sometimes deposit their runoff on surrounding properties. If your burnt landscape is receiving sheeting water, the risks of erosion are high.
o 0 Points: The slope is not receiving sheeting water from elsewhere.
o 6 Points: The slope is receiving sheeting water from elsewhere.
Approximate Level of Risk
Between 6 - 13 points = Fairly Low Risk of Erosion
Between 14 - 20 points = Medium Risk of Erosion
Between 21 - 28 points = Fairly High Risk of Erosion
Between 29 - 44 points = High Risk of Erosion
Interested in Learning More?
The scorching heat, smoke, and burned vegetation can leave your garden, trees, and soil in a vulnerable state, but with the right care, your landscape can recover. Kent’s expertise spans decades of experience working across the United States and is documented in FIRESCAPING: Protecting Your Home with a Fire-Resistant Landscape. It is available now and beneficial for all flammable areas of the world. If you would like to personally get in contact, you can reach him here.
Words & Illustrations by Douglas Kent
Mr. Kent has been working to create fire protected properties and communities since 1994. He has written the best-selling book on landscaping for fire protection (Firescaping) and has led educational efforts and landscape projects across California. He has written over 50 articles appearing in such publications as Fire Gardening, Los Angeles Times, and Sonoma Press Democrat. Mr. Kent teaches land management courses at Cal Poly Pomona, UCLA Extension, and USC’s School of Architecture and Urbanism.
Curated by Seth Calmes
