Fire Resistant Plants for Your Garden

Before choosing any fire-resistant plants, you must first establish a Home Ignition Zone (HIZ). This area includes your home and all the surroundings within a 100-foot perimeter, or 200 feet, if on a steep slope. The HIZ determines how well your home will survive wildfires. But it can also help to reduce any potential fire risk. To make your HIZ as fire-resistant as possible, you must reduce or remove any materials that could ignite. 

Within the HIZ, there is a buffer, known as defensible space. This is where the actual management of vegetation and other fuel sources around your home takes place. Defensible spaces are divided into three distinct zones, each with their own specific landscaping and clearing guidelines. Besides boosting your home’s survival, these zones provide a safe space for firefighters during wildfire events.

Zone 0

Located 0-5 feet from home, Zone 0 is also called the Immediate Zone. This is the most critical area, where embers can build and ignite homes. You must make it a non-combustible area, free of all flammable materials.

Zone 1

Located 5-30 feet from home, Zone 1 is also known as the Intermediate Zone. This is the area designed to slow fire spread.

Zone 2

Located 30-100 feet from home, Zone 2 is also called the Extended or Reduced Fuel Zone. This area is meant to reduce fuel density to interrupt a fire’s path. 

When it comes to setting up defensible spaces, not all homes are the same. Planning varies, depending on factors like ecological setting, prevailing winds and surrounding vegetation. But you don’t want to completely remove all plant life. Not only is this harmful for ecosystem health, but it may lead to increases in invasive weeds and grasses.

Contact your local fire authority or governing municipality to learn about getting a free defensible space inspection. They’ll also provide specific regulations, as firebreak requirements are site-specific and vary by jurisdiction. But generally, with gardening and landscaping, firebreak requirements depend on the zone around your home.

In Zone 0, 0-5 feet from your home, remove all flammable materials, including dry or dead leaves and grass, bark mulch, weeds and branches. Instead, opt for gravel, rock or pavers. And keep this zone clear of all vegetation, including trees, shrubs and even potted plants.

In Zone 1, 5-30 feet from your home, focus on reducing fuel by creating gaps and maintaining low vegetation. Here, aim for “lean, clean and green” landscaping.

• “Lean” means having little, if any flammable vegetation. You can apply mulch, but not in a continuous, widespread manner. Be sure to surround it with noncombustible options, like irrigated lawn. You may prefer to use hardscaping options, such as gravel, decomposed granite, rock, concrete or brick.
• “Clean” means removing all flammable or dead debris. If you plant a few shrubs and trees, ensure good spacing between them.
• “Green” means ensuring all plants are healthy and irrigated (if possible). In the spring, remove any pine needles from Zone 1. These can accumulate during the colder fall and winter months.

In Zone 2, remove excess, dried and dead vegetation. This helps ensure the removal of all “ladder fuels” — low-growing vegetation that increases a fire’s potential of moving from the ground to treetops. It also creates horizontal, continuous, non-combustible firebreaks with paths, driveways, patios and walkways. 

• Prune tree branches up to 6-10 feet from the ground to prevent flames from reaching canopies. Remove dead leaves and branches at their bases. If you have any pine needles, they shouldn’t be higher than 3 inches in depth. And keep grass at a low height, 4 inches or less.
• Trees and plants should be spaced out to increase the distance between crowns, with distances increasing based on slope percentage. To break up the continuity of vegetation, only plant a few small clusters each. But leave adequate space between plants, rather than packing them tightly together.
• Ensure firebreak maintenance by regularly removing all flammable debris from your property. This includes clearing fallen leaves and branches and new vegetation and pruning trees.
• Maintain proper irrigation to keep plants, trees and grass well-hydrated. During the fall and winter, plants become dormant and contain less moisture, causing them to burn easily. Green and lush plants are more difficult to ignite than dry and parched. Installing water features, like birdbaths, near your home can boost local humidity, lowering ignition risks. You may consider installing a drip irrigation system. You can also conserve water by mixing compost into the soil around plants.

Tip: To keep your home fire safe, avoid planting anything within five feet of your home.

While no plant is completely “fireproof,” some have attributes that make them less vulnerable. Fire-resistant plants share characteristics that reduce flammability and help them survive fires. If you live in a wildfire-prone area, you should only install highly fire-resistant plants. It’s helpful to know that plants native to your area are ideal for fire-resistant gardens. Besides requiring less water to stay hydrated, they’ve developed unique strategies for wildfire defense.

Typically low-growing and nonwoody, these plants’ traits include high moisture content in leaves and stems and fewer volatile oils and resins. They also have a tidy growing habit, with minimal leaves, twigs and bark that can ignite. Additionally, some plants have thick bark that help protect against heat. They may have open branching habits, which provide less fuel. They also have extensive root systems, boosting recovery chances after fire damage.

Avoid selecting tall ornamental grasses and other large perennials. Easily ignitable, they also die in winter, leaving behind combustible dried leaves and stems above the ground. If you must plant these varieties, always cut them back to just above the ground in the fall.

Groundcovers are visually appealing and fill in spaces that are typically covered by lawn.

Choose fire-resistant groundcovers, especially those with thick, fleshy leaves. Good options include:

• Creeping thyme: This herb is a drought-resistant perennial well-suited to borders and walkways.
• Ice plant: A succulent groundcover with bright, colorful flowers that can spread throughout your garden.
• Lamb's ear: Also called stachys, or hedgenettle, this plant has soft, fuzzy leaves that hold in moisture.
• Sedum: These tough groundcovers look good through hot summers and spread easily in your landscape.
• Vinca minor: Known as periwinkle, vinca has tough, glossy foliage and blue flowers.

Perennials add color and texture to your garden, with the advantage that they come back every year. Many are favorites of hummingbirds, butterflies and other pollinators.

Here are some tough perennial options for your garden.

• Bugleweed (Ajuga reptans): Resilient and fast-growing, this groundcover provides a dense mat that helps to smother weeds and prevent ignition. But due to its aggressive nature, it shouldn't be grown where it could impact other plantings.
• Coreopsis: This native prairie plant, also called calliopsis or tickseed, requires little effort. It tolerates almost all soil types, as long as it’s well-drained, and thrives blazing sunlight and sweltering heat. Coreopsis has bright yellow, gold or red flowers, which bloom non-stop from early summer to fall.
• Creeping phlox (Phlox sublata): Also known as moss phlox, this perennial grows close to the ground. In spring, it boasts cheery lavender, pink, rose or purple flowers. When these fade, they leave behind attractive, needle-like leaves.
• Daylilies (Hemerocallis): Each daylily bloom lasts just a day, but the plants flower for most of the growing season.
• Echinacea: Commonly called coneflower, durable echinacea is a favorite for butterflies.
• Lavender: Lavender likes dry, Mediterranean conditions and rewards gardeners with fragrant flower buds.
• Penstemon: This drought-tolerant perennial flowers in spring and attracts hummingbirds to your garden.
• Salvia: A resilient choice, salvia thrives in hot, dry locations and brings in the bees.
• Spurge (Euphorbia): Revered for their richly colored leaves and unusual flowers, these perennials are available as shrubs, groundcovers and small trees. As spurges are heat- and drought-tolerant, they do well in dry, fire-prone climates.
• Yarrow (Achillea): Yarrow’s feathery foliage holds in moisture and makes an effective fire-resistant choice.

Broadleaf evergreen shrubs keep their moisture-holding foliage throughout the year.

When building out your fire-resistant landscape, look to these evergreen shrubs:

• Coast rhododendron: Also called Pacific rhododendron, these evergreen shrubs bloom in brilliant colors in early summer.
• Camellia: Like rhododendron, camellia shrubs have evergreen foliage and stunning blooms every spring.
• Leucothoe: This well-rounded low maintenance landscape shrub is suited for sun or shade.
• Manzanita: Manzanita is a fast-growing, wide-spreading shrub used for groundcover.
• Oleander: Known for its colorful blooms and spiky, evergreen foliage, oleander is hardy in zones 8 to 11, which are generally warmer.
• Oregon grape: This coastal favorite is a staple for wildlife gardens. It features yellow flowers in spring and deep, blue berries in summer.

Shrubs, along with trees, are the foundation of successful landscape planting.

Consider these shrub options for your fire-resistant landscape.

• Agaves: Fire-smart because of their fleshy, water-retaining leaves. Their unique shapes make them perfect candidates for contemporary gardens.
• Azaleas: Revered for their attractive spring blooms. Often, they're planted for screening or hedging or as woodland borders.
• Bottlebrush: Look for compact size varieties of this popular evergreen shrub.
• Cotoneasters: Spreading, low-growing shrubs with dark, shiny green leaves that transform to burgundy in fall. They have masses of creamy white flowers that bloom in spring. In winter, they sprout red cranberry-like berries.
• Mexican bush sage: This salvia is known for pest-resistance, drought tolerance and lovely purple flowers from spring to fall.
• Red twig dogwood: A small, ornamental shrub prized for its bright red stems. It grows well in many soil types, including boggy or swampy locations.
• Rockrose: This tough, drought-tolerant shrub is suitable for natural landscape designs, especially in coastal areas.
• Spiraea: Plant spiraea for colorful blooms and foliage that last into fall. It grows best in part shade to full sun.
• Yucca: A rugged, extremely drought-tolerant native plant. It thrives in dry, desert-like climates and cold or freezing temperatures. Yucca is recognized by its stiff, sword-shaped leaves, and in summer, tall spikes of white flowers.

Fire-resistant trees typically have thick bark and fewer volatile oils, and their leaves hold in moisture. You may opt for planting deciduous trees, those that seasonally shed their leaves in autumn. They’re better than fine-needled evergreens, which have a high-resin content, like pines and junipers. But avoid deciduous trees and shrubs with peeling, papery bark, such as river birch. Consider these tree options for a fire-resistant landscape:

• Oak trees create a shady escape from the sun’s rays and are an important resource for wildlife. Oaks can grow 15- to 40-feet high and 20-feet wide, so allow plenty of room for a mature tree.
• California sycamore is a durable tree that can grow to heights from 40 up to 100 feet high. It's known for sending out deep roots that grow straight down instead of outward.
• Chinese pistache grows to a height of 25 to 40 feet tall. It is prized for its rounded, mature shape and rich, orange fall color.
• Crepe myrtles can be either tall shrubs or small trees. Their tidy habit and thin bark make them a fire-wise choice for your landscape.
• Ginkgo trees are among the oldest trees in the world. Plant them for their fan-shaped leaves and spectacular golden color in fall.
• Olive trees are Mediterranean plants and thrive in heat and full sun.