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.
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.
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.