- Author: Maggie Mah
- Editor: Cynthia Nations
Many parts of California sizzle in the summer heat, but living on the coast means spending most days under a thick marine layer blanket and being buffeted by chilly breezes. Cool temperatures and proximity to a large body of water can lull us into thinking that wildfires happen somewhere else, but climate change is turning a lot of things upside down and we now know that's not the case. How we think about landscaping is part of this “New Abnormal” of bigger, more destructive fires. We are learning that the kinds of plants we choose and where we put them can help to protect our homes in the event of a wildfire. This concept is known as “firescaping” and if the term conjures up an image of a barren moonscape reminiscent of a scene from Star Wars, that's not it. However, cling as we might to the traditional, cozy look of trees and shrubs encircling our homes, adopting a new proactive garden aesthetic could mean the difference between survival and devastation.
Pillars of the Idea: “Firescaping” is defined as designing your landscape in a strategic way to reduce the impact that a fire could have on your property. There are two key elements. The first is to minimize the amount of flammable vegetation that could “feed” a fire and the second is to interrupt the “path” of an approaching fire to slow its progress and ultimately prevent it from reaching a house or other structure.
Defending Your Space: According to studies by the National Fire Protection Association and others, most homes are not destroyed by a wall of flame but by wind-blown embers which ignite flammable materials on or near the structure. Many of the homes that survive in fire-devastated areas are those that are surrounded by 30 feet of defensible space. The good news: it's easy to see how keeping the area surrounding your home as fire resistant as possible can make an enormous difference.
Getting Into the Zones: Picture your house in the center of a circle with a series of concentric rings radiating outward. These represents the “zones” that will guide the type, placement/location and amount of maintenance and irrigation needed for creating an effective “firescape.”
Think of the first 5 feet around a house or other structure as a kind of “thin red line” when it comes to fire because preventing fire from reaching this area is crucial. It should be kept free of anything combustible, including plants. Unfortunately: “foundation plantings,” those familiar shrubs and planter boxes immediately next to the house, are highly problematic in a fire situation and need to go. (If you must have a plant right next to your house, make it a succulent in a ceramic pot that can be easily moved.) In addition to being flammable, tools, furniture, toys and pretty much “stuff” of any kind creates nooks and crannies for dry leaves to collect. In short: neatness really does count!
Next is the area between 5 and 30 feet away from your house or other structure. The terms often used to describe this area are “lean, clean and green.” In choosing plants for this area, limit the number of plants overall and make fire-resistant varieties the top priority. If properly maintained, these types of plants can trap and help to extinguish flying embers. When it comes to design, think in terms of clusters or groupings of plants with space in between. This type of arrangement makes it harder for flames to spread and climb. These areas should also be kept free of dry, dead debris. When you plant, incorporate plenty of organic soil amendments to increase the water-holding capacity of the soil and use inflammable rock mulches to hold in moisture. If flammable mulches such as “arbor” chippings are used, keep them on the perimeter and away from low lying branches and remove any large twigs or pieces of bark. Even fire-resistant plants can become problematic if not properly maintained so it is important to ensure that plants in this area get plenty of care and adequate irrigation.
30 Feet and Counting: If the perimeter of your property extends beyond 30 feet from your home, you have additional “zones.” Slope and overall terrain are complicating factors that must be considered but reducing the amount of flammable material that would allow fire to move inward toward your home and upward into taller trees is essential. This means removing all dead and dying trees, dead branches, and dried vegetation. Healthy trees should be trimmed so that lowest branches are both 10 feet from the ground and 10 feet away from other trees. Trees and shrubs that are spaced appropriately and with adequate separation from combustible materials will lower the chances of flames being able to make their way to your house.
Bottom Line: Whether or not you decide to make changes to your existing landscape, proper maintenance of the vegetation surrounding your home is a given. Anything dry, dead, or brittle should be considered kindling that even the tiniest spark could set ablaze. Also, good to know: the traditional method of shearing shrubs and hedges from the outside creates dense, flammable interiors. Diving inside on a regular basis to prune out shaggy bits, dry twigs and branches will make them less flammable. Removing any overhanging tree branches at least 10 feet away from your roof is also a must. This might require having a heart-to-heart with the folks next door and if this seems awkward, remember that minimizing the threat of fire takes a neighborhood. Ultimately, they will thank you.For more on choosing fire-resistant plants go to:
The article was written by Maggie Mah who is currently the Marketing Chair for SM/SF UC Master Gardeners. The article was edited by Cynthia Nations.