Tips for Designing a Fire-Safe Garden

When thinking about how to slow the movement of a wildfire, space is key. Design your plantings in clusters that have adequate empty space between them rather than packing the garden with plants standing shoulder-to-shoulder.

While there are lots of shrubs that will fill your garden with some shape, color, and interest, they don’t all hold up as being fire-resistant. Choose shrubs for your garden that are proven to stand well against fire, such as cotoneaster (pictured), sumac, bush honeysuckle, or hedging roses.

The tidy gardeners out there can give themselves a pat on the back when it comes to fire prevention. For the rest of us, there’s still hope! Spend a few hours each week clearing dead leaves and branches from the garden. It’s one of the most highly recommended fire-resistant strategies out there.

While no plants are completely fireproof, there are some that resist burning for longer, require higher temperatures to ignite, and may be able to slow the spread of fire through a landscape. Those with more water stored in their shoots and leaves are a safe bet. You can’t go wrong with anything from the succulent family.

When planting trees in the landscape, opt for deciduous over evergreen. Trees such as junipers and pine, while stunning, contain high resin content. This makes them highly susceptible to burning up, and quickly. Smarter options include maple, poplar, and cherry (pictured).

When planning a home garden through the lens of fire safety, it’s helpful to think in terms of spatial zones. Zone 1, closest to the house and extending out for 5 feet, is the most important to care for. Plantings here should be kept short, and to a minimum. Zone 2, extending from 5 to 30 feet out, can include more plantings, but they should ideally remain under two feet; grasses and lawns should be mowed to a length no greater than four inches. Prune trees up to six to ten feet from the ground, and for shorter trees, refrain from exceeding one third of the total tree height. Treetops should be no closer than ten feet from your home. Additionally, trees and shrubs should be clustered together in small groups to break up the landscape's vegetation. Finally, in the zone between 30 to 200 feet from your home, trees should be spaced a certain distance apart: at least 12 feet between treetops when planted 30 to 60 feet from the home, and at least 6 feet between treetops when planted 60 to 100 feet from the home.

By holding moisture underground, mulch helps your soil stay cool and moist, so it would seem intuitive that it would slow the spread of fire. However, many varieties of mulch are still combustible, particularly most types of wood chip mulch; composted wood chips are the least combustible and hence the safest, but should be used with caution. The safer bet is to stick with noncombustible rocks, gravel, concrete, and pavers as a highly effective fire-resistant strategy. 

When it comes to a fire-resistant garden, including smart hardscaping features can be just as important as choosing the right plants. Patios, retaining walls, and stone walkways can earn their weight by acting as barriers to a quickly spreading fire.

Good garden maintenance is good fire planning. Plants that are dying or thirsty are likely to rapidly ignite and encourage fire to spread. This is great incentive to invest in a good drip irrigation system to make sure your plants are watered deeply and regularly, without wasting water in the process.

While ornamental grasses are lovely, they require a level of upkeep and time that most of us don’t have. This leads to tall, dry, overgrown grass that could catch fire in the blink of an eye. Opt instead for short, low-maintenance groundcover such as succulents or santolina.