In the hot, dry months of summer and early autumn, your landscaping might not be the first thing that springs to mind in terms of wildfire preparedness. But choosing a fire-resistant design for your outdoor space will add one more layer of protection to your home—something to consider if you’re in a wildfire-prone area. Fortunately, making the landscape around your home less fire-prone isn’t as much work as you might have thought.
A hot-enough fire will burn any plant
The first thing to remember is that any plant will burn under the right conditions. Rather than choosing the right species of plants, creating a fire-resistant yard is more about careful spacing, pruning, and focusing on the characteristics of the plants you choose. Plants that have lots of resin or wax are more likely to burn hotter while plants that have a thicker undergrowth are more likely to hold onto small embers that can smolder and reignite. Plants that drop needles, lots of leaves, or bark can create flammable ground cover if not regularly raked.
Keep tree branches away from undergrowth
When designing for fire resistance, you should make sure to prune tall trees at least six feet from the ground. This creates a gap between the low branches of the tree and the grass, where flames can travel. Since a tree’s trunk is larger and more dense than a smaller branch with leaves or needles, the trunk will often resist fire damage more effectively than the branches of the tree. A similar rule applies when pruning trees above hedges or shrubs. The minimum distance between the lowest branch of a tree and the top of a shrub should be three times the height of the shrub. This spacing will make it more difficult for a fire to spread from the ground to the canopy of the tree, making it easier to fight.
Keep flammable material away from your structure
Spacing is also important when planning where you should plant in relation to your home. Having plants within five feet of your home or any structure will increase the likelihood of a brush or grass fire becoming a structure fire as well. While mulch can be useful in terms of keeping the soil moist, it is not recommended to be used within five feet of a structure as it can be combustible if it’s dry. Keeping plants in clusters with the surrounding area being low vegetation or hardscaping like gravel will slow the spread of a fire in your yard and reduce the risk to nearby structures.
Keep your ground cover damp
Watering regularly to keep plants and soil moist can help slow a fire down and make it less likely to spread. If you have wood mulch, make sure that it’s spread in a thin layer of less than three inches and that you water it during wildfire season to reduce the risk of it becoming kindling. You can also choose compost mulch, which is less combustible than woodchips alone. Keeping a ground cover of low-growing vegetation can help the soil hold onto moisture and watering your yard during hot, dry times will help reduce the risk of fire as well.
Prune shrubs
Pruning shrubs to prevent them from growing thickets of slender, narrow branches is a good practice when designing for fire prevention. Thicker underbrush with lots of dry material inside is more combustible than plants with broader branches with only healthy leaves attached. If you do have a plant or two that’s less suited for this type of pruning, consider spacing it at least twice its height from other plants to keep it from becoming a source of fire spread.
Landscape with flame-resistant materials
Gardening with non-combustible materials like stone, brick, and concrete is also a good way to reduce the risk of fire spreading to your home. Using gravel as a spacer between plants, using boulders or stepping stones between plants, and paving patios with brick or concrete can create more space between plants. Combining hardscaping with the other methods to slow a fire down can make a difference in protecting your home.
