The devastating Pigeon Valley fire in Tasman 2019 which eventually burned around 2300ha of commercial plantation forest, property and pastures, and had a final perimeter of 35km. A home and shed were also lost in the fire. Photo: Supplied
As wildfires become more frequent and destructive in Aotearoa New Zealand, everyone can take proactive measures to help protect their homes and buildings. Fire and Emergency New Zealand advises low flammability planting and creating defensible space around buildings, which can reduce the intensity of a wildfire and slow its spread, limits the impact and damage.
Low flammability planting buys you time
Fire and Emergency Community Risk Manager Steve Trigg says low flammability plants play a crucial role in mitigating wildfire risk. These plants, which are often native to New Zealand, have high moisture content dramatically reducing potential fire intensity, offering better protection to homes, other buildings, and crops. “Fire and Emergency New Zealand has a plant flammability directory on our website, www.checkitsalight.nz, that includes scientific data to help homeowners make informed planting decisions,” he says.
“These plants are not fireproof, but they do reduce the risk and slow down the spread of a wildfire, buying time for the firefighters to arrive and contain it,” he says. “In contrast, highly flammable plants, like manuka/kanuka, dry grass and pine trees, contribute to the spread of fire. We advise to either remove or relocate highly flammable plants, especially those close to homes or buildings,” adds Steve. If that’s not practical or desirable, he says, there are other options to help reduce the risk. Pruning plants to prevent them from touching one another, regularly clearing dead or dry material, and trimming trees’ lower branches up to two metres can reduce the likelihood of fire spreading. Interspersing high flammability plants with low flammability species is another helpful approach.
A buffer against wildfire
Defensible space is the area around a building that has been designed and managed to reduce the risk of fire spreading. A buffer between your home and potential wildfire fuel, such as trees, shrubs, and grass, can significantly alter the fire’s intensity and direction. “Homes with properly maintained defensible space are more likely to survive a wildfire,” Steve Trigg says. “This is because the space disrupts the continuous fuel that fire needs to spread. Defensible space provides safer access for firefighters and evacuation efforts.”
The defensible space around a property has two safety zones:
• 0-10 metres: This zone focuses on minimising fuels around the home as much as possible. Remove or relocate highly flammable plants, keep grass short, and clear debris from gutters and areas around decks.
• 10-30 metres: In this zone, the emphasis is on vegetation management. Create gaps in the fuel load by spacing out plants, pruning trees, and using low flammability plants to break up high-risk areas.
For properties on a significant slope, these distances need to be increased on the downhill side. While creating defensible space does require effort, it can be done incrementally and on a budget. Many measures, like regularly clearing dead or dry vegetation or pruning plants, are low-cost but highly effective.