Avoid These Plants to Help Keep Your Garden Fire-Safe

A fire-fuel-rich landscape of highly flammable eucalyptus, unmaintained dry grasses andresin-filled juniper

The key to recognizing which plants could put your home at a greater risk is to “think” like a wildfire. Survey your landscape and see if you can spot any plants that would be great for kindling — dry grasses, trees with peeling bark or shrubs that have dried to thickets — or plants that are oil-rich and easily combustible. These are all plants you want to avoid in a fire-smart landscape.
3 Categories of Plants to Avoid for a Fire-Wise Landscape
1. Plants that accumulate dead material. A wildfire can quickly race through a landscape strewn with fallen leaves and needles, dead plants and dry grasses. In gardens, avoid plants that have characteristics like peeling bark, frequent leaf drop or the tendency for dieback.

California buckwheat (Eriogonum fasciculatum) 
Staying on top of maintenance is crucial and can turn a “high-risk” plant into a “lower-risk” plant. For example, twiggy perennials, such as native California buckwheat, make excellent drought-tolerant garden plants and don’t present an above-average fire risk if maintained properly. If neglected, California buckwheat and many other woody perennials have a tendency for dieback, often hidden between an exterior of green leaves. A twiggy, dead interior on any plant can be highly flammable but is preventable through frequent cutting back.

Miscanthus grass. Ornamental grasses — like garden favorites feather reed grass, fountain grass, miscanthus, blue grama grass and others — can be particularly dangerous, as many enter dormancy (grass blades turn golden and dry) in mid- to late-summer and fall, when fires are at a higher risk. In fire-prone areas, keep ornamental grasses cut back or avoid planting them. Also mow any wild grasses bordering your property to prevent fire spread.
Plants to watch out for: Ornamental grasses, eucalyptus, bamboo, coyote bush (Baccharis spp.), California buckwheat (Eriogonum fasciculatum), coastal sagebrush (Artemisia californica), palms, pampas grass, scrub oaks (Quercus spp.) and others

Photo by Henry Burrows
The dry leaves and hollow stems of bamboo — technically a giant grass — can easily ignite in a wildfire. Keep bamboo away from buildings, or avoid planting altogether, in areas with fire risk. For bamboo, trees and shrubs, remember to keep leaf litter picked up to avoid buildup of a highly flammable material.

Photo by Amanda Slater
Eucalyptus trees are a triple fire threat: The plants accumulate dead material, all parts of the plant contain resins and the leaves are less moisture-rich than deciduous trees. Fire Safe Marin, a California nonprofit, advises homeowners in at-risk areas to remove or intensely maintain (thin, prune and remove detritus) eucalyptus trees within 100 feet of structures to reduce fire hazard.
Plants to watch out for: Acacia, bamboo, eucalyptus, Scotch broom (Cytisus scoparius), common gorse (Ulex europaeus), larch and others.

Maintenance is Key to a Fire-Safe Landscape

Many types of plants are flammable if not properly maintained, but the risk of any given plant can be reduced if it’s well-watered and pruned free of dead materials. If you live in an at-risk area, stay on top of garden chores like cutting dead branches, keeping grasses and woody perennials trimmed and sweeping up fallen leaves and needles. If there is a fire warning, make sure all plants are given a deep-soak watering.

What to Plant Instead
Plants with a high water content — such as succulents and cactus — and a variety of low-risk trees, shrubs and perennials can help prevent the spread of fire through a landscape. Maintenance is key, even with lower-risk fire-smart plants, as is planting in zones of safety.

It’s also recommended to check region-specific fire safety guidelines from your county fire department. For more information on fire safety, check out resource pages on the Cal Fire and Fire Safe Marin websites.