Firewise Landscaping by Linda Langelo, CSU Horticulture Program Associate
No plant is “fireproof”. Plants with high moisture content such as succulents are have a higher resistance to wildfire. There are other plants such as Oriental Poppy, Saxifrage, Rockrose and Sea thrift which require high moisture content and have a high resistance to wildfire. Native species are the best overall. For a more comprehensive list go on-line to Colorado State University Extension Website for Fact Sheet Number 6.305 titled, “FireWise Plant Materials”.Have you ever considered the types of plants and their proximity to your home can actually save your home from catching fire in the event of a wildfire? These FireWise plants can reduce the amount potential fuel during a wildfire. Being FireWise means placing these plants in a defensible zone by creating a gap or space around your home making it harder for those plants to add fuel to the fire. Remember you start a fire with kindling. In other words, the kindling is the low intensity heat working to higher intensity. The pine needles and the wood chips are the kindling to burn the logs.
Other characteristics of plants to consider for your landscape are those that grow slowly and require little to no pruning. Groundcovers which are short and stay close to the ground are also good choices. Plants with open and loose branching such as mountain mahogany have a low volume of vegetation. Any plants such as aspens which grow without accumulating large amounts of dead debris.
When deciding where to place these plants in your landscape, give your home three to five feet of space or defensible-space away from the foundation before planting. Be sure to start with shorter plants closest to the defensible-space and gradually heighten the planting, if desired. Continue to use decorative rock, add pathways, add islands through your landscape to break apart one big mass planting reducing plant fuel. Lots of scattered plantings with large spaces between them will reduce the possibility of fuel for igniting your home. Breaking up these scattered beds with irrigated lawn is also a good idea. Just remember to keep the grass mowed to a low height. Keep the grass low around the house, decks, steps, any outbuildings, firewood piles, propane tanks, shrubs and trees with low-growing branches. The low intensity of a grass fire may be enough to ignite the type of siding on your home, the deck wood steps or that low-growing branch on a tall tree.
The defensible-space can be rock or gravel surface. The flatter the surface such as flagstone or pavers, the less it adds to any wildfire. In fact, a wide path between the foundation of your home and the landscape plants is considered a desirable defensible-space. Be sure to keep the path clean and keep the gravel clean. Any debris that accumulates in the gravel or corners of the house or deck steps or any steps is fuel to ignite your home. Keeping this debris cleaned-up is a continual process.
Think about the trees that surround your home. Are they needled evergreens? Do the needles collect in the gutters and on the roof lines? If so, these must be cleaned-up on a regular basis as well. Leaves of deciduous trees can also collect on the roof and in your gutters. If there are trees close to your home, you might want to remove them. The radiant heat can ignite your home. If your house is surrounded by evergreens and/or deciduous trees, remove trees up to 100 feet away from your home. When planting shrubs around trees be are sure to plant them 10 feet from the end of the tree’s branches. Understory plants can become ladder fuels. These fuels create a link to reaching the tree’s branches and eventually setting the tree on fire.
With any of your trees, it is recommended removing branches up to ten feet above the ground or one-third of the live crown. Tree can also be subject to fire spreading from crown-to-crown. To prevent this, plant trees at least 10 feet between the edges of the tree’s crown. It is recommended to leave 30 feet between clusters of tree two to three trees in a moderate or high area around your home. (The first area is right around your home – all hazard area, then zone two moderate or high) Again, under any of these trees once the branches are removed if there is grass and weeds’ mowing is required to keep them low and prevent the tree from catching on fire. For any trees with suckers, remove them as well. They can be fuel for surface fires.
The idea to all of this is creating a more open landscape with lots of defensible-space of flat surfaces that do not burn as low-intensity such as wood chips or evergreen needles that act like match sticks. Match sticks are the small items that carry enough energy to start a bigger fire if there is more fuel nearby. Remove any dead material from 10 feet around your house and under your deck. Boxing the underside of the deck with fire resistant materials can be helpful. The other thing to consider is properly watering and maintaining the plant material around your home. Regular watering is helpful in slowing a fire.
As embers can be carried throughout your property, they can land on top of your wood deck. The newer deck materials are more resistant over wood decks. Do not place wood decks at the top of a hill. A terrace is the better option. If you have wood fencing that connects to your home or any structure, place a metal gate or metal section between the structure and the rest of the fence. Concrete patios widen that defensible-space around your home. Stone retaining walls can be used throughout the landscape to separate island beds.
If you are interested in more information about FireWise Landscaping contact your local Extension office or go on-line to CSU Website for more publications on fire prevention go to Wildfire and Forestry.
For more information visit www.ext.colostate.edu
Submitted to BARN Media by: Linda Langelo, CSU Horticulture Program Associate