Creating a Landscape that Fights Fire AND Saves Water

By Debbie Arrington
Guest Writer

Can you fight fire and save water at the same time? With thoughtful planning and planting, your landscape can help protect your home from wildfire while also cutting down on water use.

It’s called “firescaping,” a combination of fire-wise and water-wise landscape concepts that may be the perfect blend for drought-challenged, fire-prone California.

“Firescaping has a dual purpose; it’s the process of creating a landscape that’s resistant to fire that uses resources as efficiently as possible,” explains Kevin Marini, community education specialist for the UC Cooperative Extension Master Gardeners of Placer and Nevada counties. “In California, that resource is water.”

Marini has firsthand experience with firescaping. His Placer County home sits on seven tree-studded acres on a slope in the Sierra foothills.

“The threat of fire is very, very real for me on a daily basis,” he said. “But wildfire is pretty much a threat for every Californian, no matter where they live. We tend to focus on the wildland-urban interface like where I live, but suburban neighborhoods need to be aware, too.”

Firescaping is different from most water-wise landscaping techniques in that the focus is to retard fire danger while at the same time cut down on water use – and still have a beautiful, enjoyable, vibrant landscape.

“As a gardener, you need to retrain your brain,” Marini said. “As gardeners, we tend to pack a landscape with as many plants as possible. We layer them in borders and beds, and keep adding more. Typically, landscapes are lush with different levels of plants, from groundcover to shrubs to trees. But that lushness is not enough to protect it from fire.”

However, all those packed plants can be potential fuel for a wildfire. Firescaping trades lushness for leanness.

“It looks different from a traditional landscape,” Marini explained. “There’s space between plants instead of continuous borders or packed beds. It’s mostly a collection of low-growing plants, spaced well apart.”

In firescaping, start be creating “defensible space,” a zone that extends 100 feet in all directions from your home or any other structures on your property. According to CalFire guidelines, the five feet closest to a building is most critical.

“You don’t want anything close to the house that an ember can catch fire,” Marini said.

That includes mulch, as well as plant material. Instead of wood chips, gravel or rock mulch is best in that first five feet.

Water-wise gardening depends on mulch to retain soil moisture. Firescaping also makes use of mulch, but not as thick.

“It’s all about density,” Marini said. “Typically, for water-wise gardening, we master gardeners recommend 3 to 5 inches thick. In firescaping, you need only 1 to 2 inches.”

Deeper mulch allows embers to smolder. Also, think about the mulch’s flammability. Besides inorganic gravel, arborist coarse wood chips – a mix of tree trimmings – is a good choice. “It’s a mix of live and dead wood, so it isn’t just dried-out wood chips,” Marini said. The most flammable mulch: Gorilla hair or shredded bark.

Think about how a wildfire spreads and moves through a landscape. Fire tends to burn uphill, making dense groundcover on slopes problematic. Clumped bushes under taller trees give flames a leg up into branches. Trees that overhang your roof can drop embers.

Any plants close enough to touch leaf to leaf can be a fire danger. That includes many traditional borders or hedges.

“The outside of a hedge may look green, but the inside can be all dead wood,” Marini said. “The middle of the hedge is a major fire danger. It can go up like a torch.”

A big difference between firescaping and low-water gardening: Plant choice. Several favorite low-water Mediterranean plants such as rosemary or lavender burn easily due to the high oil or resin content in their leaves. Juniper, pine, incense cedar and other conifers also are not fire-wise – even though they may be native. Low-water native grasses tend to burn rapidly.

“Avoid plants with a lot of resin or oil,” Marini said. “Go for bigger leaves that hold more water.”

To help fire-proof the area around your home, break up the potential flow of flame. Use non-flammable hardscape – paths, driveways, patio, etc. – as firebreaks winding through your landscape. Keep trees and shrubs far enough apart where branches don’t touch.

Within 30 feet of structures, keep your landscape low, lean and clean, says CalFire. That gives your home a buffer zone away from flame and embers.

“You want to keep embers away from your house – particularly your roof,” Marini said. “You don’t want trees dropping embers on your roof, which means you want to keep fire out of the tree tops.”

Traditional multi-layered landscapes create “ladders” for fire to spread up into trees. So do vines that can grow up walls or tree trunks. Low branches on trees also act as ladder steps, boosting flames upward. Eliminating those fire ladders greatly decreases fire danger.

No landscape is “fireproof,” Marini noted, but design, materials and plant choice can make a huge difference in determining if a spark catches or flames spread. So does proper irrigation. Make sure plants get the water they need to stay healthy.

“The biggest part of firescaping I learned: Keep plants really healthy, watered and well spaced,” Marini said. “A healthy plant has a much better chance for survival – from drought or wildfire.”

Debbie Arrington is a longtime home and garden reporter and co-author of the blog Sacramento Digs Gardening: