Marin Master Gardeners
University of California
Marin Master Gardeners

Firewise Landscaping

firewise landscaping
As we approach fall and have had no rain since spring, it’s time to contemplate the most dangerous time of the year. Fire season is underway and may be worse this fall due to last winter’s rains generating much growth, which accumulates into fuel loads in our gardens and wildlands. Sudden oak death and the die-off of pines due to various ailments further complicate the problem.

We need to think of plants as fuel and clean up dry leaves, pine needles and other flammable debris. Mulch is always recommended as a way to save water, but use wood chips and never highly flammable shredded redwood bark mulch known as “gorilla hair.” Look at the lay of your land and where prevailing winds come from. If you live on a hill and someone drops a cigarette at the bottom of your property, which is covered with dry leaves or grass, your house could be toast.

Fire departments around Marin are keen on defensible space, particularly where houses abut wildland in what’s known as the wildland urban interface. If you live near open space you likely have a requirement to cut back dry annual grasses in the early summer months and create at least 100 feet of defensible space around your home, more if you live on a hillside.

Of course, many in Marin live on small lots on hillsides that are vulnerable to fire and there’s only so much that can be done about neighbors unless they disregard the rules about cutting and removing fuel from hillsides.

But the reality is that maintenance is more important than plant selection and it can be a dangerous illusion of safety to rely only on planting so-called fire-safe plants that show up on a list. For instance, coast live oak is on some fire-safe lists, but if a tree is on a hill that’s not irrigated and below is some dry grass and other dry shrubby plants, all it takes is a spark and a little wind to set off a potential wildfire.

There are lists that purport to distinguish between plants that burn easily and those that don’t on Marin Municipal Water District and Firesafe Marin websites (firesafemarin.org), but remember, maintenance and defensible space is the key to fire safety. You can also take a look at the UC article “Sustainable and Fire Safe Landscapes” at cemarin.ucanr.edu.

One in three California homes is estimated to be at risk of being affected by wildfire. Think back to the 1995 Vision Fire at Point Reyes that burned 45 homes and over 12,000 acres of wildland. Or worse yet, the Oakland Fire of 1991, started by a grass fire that destroyed over 3,000 dwellings, killing 25 people. The October 2017 Tubbs fire in Sonoma and Napa County burned more than 5,600 dwellings and killed 22 people, with some of the worse damage in Santa Rosa.

The urban corridor in Marin is vulnerable to such fires also, and after those terrible conflagrations our fire departments got together and formed Firesafe Marin as a way to educate the public. If you’re thinking about remodeling your home, look at roofing materials such as tile, stucco siding, enclosed undersides of decks, and small eave overhangs as ways to ensure your future safety. Calfire’s website has information on fire safe building materials at fire.ca.gov.

In dry California, we’re always encouraged to economize on water. Remember, though, appropriately well-hydrated plants near open space resist fire much better than dry ones.

Some local fire departments will come survey your property for fire safety. Remember, all plants are flammable and the more densely planted your garden is the more likely you have plants that either don’t get enough water or create a ladder effect during a wildfire and become fuel.

Bottom line: don’t overplant, remove the most flammable plants, limb up trees 10 feet from the ground, and be fire safe!


Original article by Diane Lynch (9/22/17) for the Marin Independent Journal
Edited for MMG public website by Bonnie Marks 7/24/18

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