Why should we worry about our landscaping? Firewise landscaping will allow time for safe evacuation and increase your home’s survivability by reducing the possibility of ignition, lowering fire intensity, and reducing how quickly fire spreads near your structure.
In Lake Wildwood, we have two issues to consider when purchasing plants. One is the wildlife (deer) and the other being combustibility. While there are several plant lists on the internet, our research has not found a list that covers the deer and the combustibility issues specific to Lake Wildwood. For that reason, the Fire Wise Committee has put together a limited list of suitable plants that cover both issues. Please see the Reference Link List. One list shows plants that either are easily managed at two feet tall (see rule R-6.30.05). These are a good choice for exit routes at the roadside or along your driveway. The other list focuses on screening plants and shrubs.
Since it’s not possible to cover all suitable plants, here are some things to think about while plant shopping. Does the plant grow without accumulating large amounts of combustible dead branches, needles or leaves? Examples of plants to avoid are scotch broom, rosemary, wormwood, grevillea, many grasses, and juniper. Rosemary and Oleander are discouraged due to their extreme flammability, high resin content, and in the case of Oleander, should it catch fire, extreme toxicity of smoke (per local fire department recommendation). Other plants to stay away from are plants that have high sap or resin content and low moisture content. Most broad-leaved trees are less flammable, avoid needle like plants like conifers (pines, firs, spruce, and juniper). For a limited list of plants to avoid click on Hazardous Vegetation in the Reference Link List.
Placement and maintenance of trees and shrubs is as important as the actual plant selection. Plants nearest your home should be more widely spaced and smaller than those farther away. These plants should be in small irregular clusters and islands, rather than in large masses. Break up the continuity of the vegetation (fuel) with decorative rock, gravel, and stepping stone pathways to help modify fire behavior and slow its spread. Avoid using mulch that consists of pine bark, thick layers of pine needles, or other materials that can easily carry fire near any structure. Regular maintenance to remove dry/dead material and debris is critical.
A lot of the handouts we get from the State, County or Fire Safe Council talk about “fuel modification area”. That term is referring to plant placement and separation. Plants should be separated with non-flammable spaces as discussed above. As a general rule on level ground, plants or small cluster of plants should have spacing of two times their height. An example would be a two foot tall plant or small cluster of plants should be separated by four feet of non-flammable material. Click on the Reference Link: Fuel Management Area (FMA) and Mosaic to see a spacing diagram. Note that Cal Fire also has recommendation on plant spacing when a slope is involved. Fire travelers faster up hill, so spacing should be increased based on the degree of the slope. See the Reference Link List for spacing on a slope recommendation Cal Fire – Consider Slope with Vegetation Placement.
Maintenance is critical. Prune and remove all debris and dead materials. Remove all tree branches up to at least 6 feet from the ground. In Nevada County, at least 15 feet if within 10 feet of the side of the paved portion of the road. Allow extra vertical space between shrubs and trees. Lack of vertical space can allow a fire to move from the ground to the brush to the tree tops like a ladder. Plant and maintain fire-resistant vegetation that is healthy and green throughout the year. Keep all vegetation irrigated, using rock mulch to hold moisture. See Reference Link List: Editing your Existing Landscape for Defensible Space for proper maintenance.
Sign up for a free and confidential defensible space advisory visit at the Nevada County Fire Safe Council.