With wildfires on the rise, many places are beginning to look for ways to protect properties from destruction. One practice that is becoming increasingly popular in some towns and mandatory in places like Marin County, California, is fire-resistant landscaping. 

Fire-resistant landscaping, also known as fire smart landscaping, refers to using specific gardening and lawn care techniques to stop fires from reaching your home. It’s more than just keeping your yard maintained. It’s also selecting fire-safe plants and strategically placing them in your yard.

You should consider practicing fire-smart landscaping if you live in an area at risk of wildfires. It’s an inexpensive way to control damage and, in some cases, may lower your home insurance costs. This article will cover the best fire-resistant landscaping practices for protecting your property. 

Are there really fire-safe plants?

Fire-safe or fire-resistant plants are those that do not readily ignite from a flame, and while a fire could injure or kill them, their leaves and stems do not significantly add to the fuel. However, all plants can burn under certain conditions, regardless of being classified as fire-safe. The flammability of a plant has to do with its specific characteristics, environmental conditions, and maintenance. 

For example, a plant with an adequate water supply will have well-hydrated leaves and will take longer to ignite. On the other hand, a water-deprived or stressed plant will have drier leaves and could have accumulated dead materials. The latter condition will increase combustibility. Therefore, a plant could be marked as fire-safe in one condition and flammable in another.

How to determine if a plant is fire-safe

Be wary of fire-safe plant lists. As stated above, it is difficult to classify plants as flammable or non-flammable, given that their combustibility can change based on their environment and maintenance. Instead, the focus should be on the plant’s characteristics, placement, and yard maintenance practices.

Characteristics of fire-resistant plants and trees

To determine a plant’s ignition probability, Cal Fire encourages you to consider the following criteria:

• Does the plant contain waxes, oils, or resins?

Plants, such as cone-bearing shrubs and trees (think pine trees) with high volumes of sap or resin are more likely to ignite. Once ignited, they burn more quickly and support fast-moving wildfires. 

• Plant Structure: Open-Growth or Dense?

An open-growth structure makes a plant less susceptible to catching fire, while a plant with densely-packed branches is more likely to ignite. In addition, dense plants may have dead materials packed inside, enabling them to capture embers and facilitating ignition. 

• Speed of Plant Growth

A rapid-growing plant may quickly grow out of control and intrude in Defensible Space zones, which we will explain later.

• Potential Height of Plant

Just like the pace of plant growth, a plant’s height will influence the amount of maintenance required. 

• Bark-Shedding Plant?

Plants that shed bark require more routine cleanup. You’ll need to keep the plant base clear of dead bark and other materials, as these are highly flammable. 

Cal Fire suggests that pollinator-friendly, drought-tolerant, or native plants can be optimal choices based on the criteria above; however, they may or may not be more fire-resistant than other plants.

Plant Placement

Plant placement is a crucial part of building a fire-safe property. The most obvious factor to consider when placing a plant is whether it touches your home, including a deck or chimney, or could grow to touch it. Placing vegetation in contact with your home can increase the chances of a wildfire destroying it. 

Creating Defensible Space Zones will decrease the chances of fire reaching your home. These zones will serve as buffers between your home and vegetation. Within 0-5 feet of your house, you should only keep low-growing, non-woody plants. Also, be sure to keep them adequately watered and maintained.

In addition to minimizing vegetation growth, you should be prudent in keeping the area closest to your house free of dead or dying plants (trees, shrubs, grasses, weeds, etc.). Remove remains such as leaves, sticks, and bark.

Yard Maintenance 

As for the rest of your yard, you should be proactive in maintaining it to prevent the spread of fire. Here are some tips for landscape design and maintenance:

• Remove all dead or dying plants from the ground.
• Make trees more fire-resistant by removing branches close to the ground and trimming the dead branches.
• Keep your lawn mowed according to local requirements.
• Clear roof and gutters of debris and vegetative remains.
• Use a non-flammable mulch, such as gravel, close to your house instead of wood chips or organic mulch.
• Place firewood far from your home.
• Use non-combustible materials like concrete or stone or fireproof fencing. 
• If you have a deck or patio, limit the number of combustible objects you keep on it (i.e., wood furniture, planters, etc.).
• Properly space or trim trees based on the type and size of the plant and slope of the land.
• Properly water all plants.

These are some general fire safety recommendations to consider when gardening and landscaping, but always follow local guidelines regarding types of plants, spacing between them, and other landscaping regulations. Also, you should check with your local nursery, landscape contractor, or county’s UC Cooperative Extension service for advice on fire-resistant plants suited for your area.