Oct. 16 2012 11:03 AM

Firewise Landscaping

WILDFIRE! The very word sends terror through the hearts of homeowners, particularly those who live in “fire country.” Homes turned to ashes, miles of blackened earth...stunned families huddled together, trying to make sense of the tragedy.

Even more tragic is the fact that some of these losses might well have been prevented with the right kind of landscape design, irrigation and maintenance.

When it comes to wildfires, those of us in the landscape business can make a big difference. Rolland Kuhr, owner of Naturescape Designs in Jackson, Wyoming, is a firewise landscape contractor, landscape architect, arborist, and consulting arborist. He points to the recent Colorado wildfire for telling examples of what can go wrong…and what can go right. In that fire, called the Waldo fire, 346 homes were destroyed, with property damage of $110 million.

“I saw lots of pictures of the wildfires in the mountains here in the West,” Kuhr declares. “But there was one particularly striking aerial photo. It was one lone house in the middle of the forest, surrounded by a green, irrigated lawn. Everything around this house had been blackened by fire. But this one house, where they did everything right, was still standing.”

“Hold on,” you may be saying, “Isn’t that what I already do? Design landscapes, irrigate them and maintain them?” Not exactly. To truly call yourself a firewise landscaper, you need to design, irrigate, and maintain in a way that both maximizes beauty and minimizes fire danger.

In a nutshell, you need to design with defensible space in mind, and choose fire-retardant and fire-resistant plants. You need to irrigate to keep lawns, plants and trees green, even when nature wants to make them brown. And you need to maintain your customers’ landscapes so that dead branches, needles and dry leaves won’t become fuel for a conflagration.

With drought conditions and high temperatures continuing to scorch much of the nation, offering firewise design, irrigation, and maintenance is more critical than ever. Nor should one underestimate the scope of the problem. While massive fires like the Waldo blaze get the headlines, thousands of smaller fires are just as dangerous to your customers’ homes and properties.

Despite fire danger, people want to live in ‘natural’ surroundings. A home in the middle of a forest, or on a hillside with a spectacular view, can be an irresistible draw to those who can afford it. But natural doesn’t always mean ‘good for humans.’ People forget that periodic wildfire is also natural.

How can one minimize the hazards of living in the forest or on a wooded hillside, while creating a beautifully landscaped environment? Design, irrigate, and maintain using zone theory.

Douglas Kent, of Douglas Kent & Associates in Orange, California, is a landscape architect, landscape contractor, and ornamental horticulturalist. He’s the author of four books, among them Firescaping: Creating Fire-Resistant Landscapes, Gardens, and Properties in California’s Diverse Environments (Wilderness Press, 2005).

Kent is an expert on zone theory.

He says that the concept was created in the early 1960s in response to the 1961 Bel Air fire in Los Angeles, California. That fire torched 484 homes, burning up a set of canyons on the west side of the city and down the other side. In the wake of the destruction, its cause and spread were carefully analyzed.

“The principles of zone theory,” Kent says, “basically, are these: next to a structure, you use fire-retardant plants—real water-needy ones. As you move further out from the structure, you use fire-resistant plants.

They have more adaptations to live with fire.” In effect, you are creating zones of defensible space around the dwelling.

“If I had a magic wand, everyone would have 100 feet of defensible space that was lush and green around their property,” said Sarah Foster, Washington State liaison for Firewise Communities. “It would make it so much easier for firefighters.”

In reality, however, such a separation is rare.

“You want to have a clearance of about ten feet away from a structure, minimum,” says Kuhr. “Next, you want to have defensible space that is green, a minimum of 30 feet from the structure. You can still have foundation plantings next to the building and surround that with, a nice, green lawn.”

“You want to keep a yard like a park, not a forest,” says Foster. “You want healthy, green grass and healthy plants that are separated from one another, so flames can’t jump. You don’t want to allow flames to get up into a tree. That’s called a ladder. Once flames reach the top of the tree, the fire becomes a crown fire (fire in the top branches of a tree). It’s very, very difficult to control when that happens. If you can keep a fire on the ground, you really give firefighters a chance.”

Along with creating defensible space, a firewise landscape contractor will choose firewise plants for his customer. “Living in fire country doesn’t mean that people have to have rocks for 30 feet around a house,” says Foster.

No plant is fireproof. “Every plant will become flammable at some point,” says Kent. “What you want are plants that are fire-resistant and fire-retardant—plants that are only going to sizzle when you throw 2000 degrees at them.”

Kent suggests succulents, calla lilies and impatiens, plants that are water-needy or water-retaining.

Many fire-resistant plants are natives that may actually burst into flame but they still resist the effects of fire. “They may ignite fast but let the fire pass through them,” says Kent. “They’re quick to re-sprout in the wake of the fire. In fact, they may actually need fire to sprout.” Foster counsels the use of plants that don’t have fire-feeding oils or tannins. These plants are fire-retardant, but can still make a landscape beautiful. “There are a lot of fire-retardant plants that grow well in lots of climates, and still have color and texture.”

As far as trees are concerned, Foster recommends planting deciduous trees that grow quickly. The quicker the growth, the more likely that a fire will not become a crown fire, since the crown will be higher above the ground. There’s one other big category of fire-retardant/resistant vegetation to consider: garden food plants and fruit trees.

“Anything from perennial and annual crops all the way to trees and shrubs,” says Kent. “Fruit trees, when they’re properly maintained, are the most fire-retardant plants we can grow. Their structure’s not very flammable at all.”

Whatever plant material you choose, you want to keep it green, especially in times of significant fire danger. Proper irrigation is so vital.

By now, you may have noticed a conflict between two very worthy goals—water conservation and fire resistance. This summer, we had unprecedented drought through much of the country. Those dry conditions contributed to wildfires. Water is scarce, and we need to conserve it. At the same time, we want to keep things green—and that takes water. The key is to strike a balance between those two seemingly diametrically-opposed ideals.

It is possible to split the difference. If you’re in an area that’s prone to shortages, suggest some basic water conservation ideas, such as using storage barrels for reclaiming rainwater when it does rain. (Those water barrels can come in handy during a fire, too.) Or irrigating with recycled water, or graywater. Using the latest smart controllers that only waters when it’s necessary. And when there are fire warnings and watches issued by the authorities, don’t skimp on watering.

You can be proactive with your customers when it comes to being firewise. Even if you’re not part of the initial planning of a landscape, you can still help homeowners protect their property. The perfect time is when you’re doing routine maintenance.

Walk the property with the homeowner. Point out dead trees or woody masses, and explain to him how dangerous they are. “Most fires start on properties through flying embers, ‘firebrands,’” says Kent. “A little spark finds a bed of material to ignite. Now, a fire may last only a couple of hours, but a firebrand can last for days. There are so many stories like this—a fire roars through a community, then is put out. Later, a home that survived the initial fire is torched by a firebrand, because it landed in a pile of something highly ignitable and off it went.”

The moral of the story is, “Don’t give it that pile of ignitable material.”

Perhaps the best way to spot potential danger on a client’s property is to do what Kent suggests and “be the fire.” That means trying to think like a fire. Ask yourself the key questions as you survey the property. If I were a wildfire, where would I go? What’s the easiest path for me to achieve my goal of getting bigger, harder to stop and consuming everything in sight?

That’s where maintenance makes all the difference. “It’s all about maintenance. In my opinion, maintenance is fire prevention,” says Kent. “A plant-less landscape is only going to get you so far. It’s getting out there and doing the maintenance. It’s absolutely critical.”

“Keep the trees pruned, so they aren’t loaded with dead branches—that’s just fuel,” said Kuhr.

“You want to keep a landscape lean, clean and green,” agrees Foster. “If you have a major storm during the winter, you have to go out in the spring and get rid of the debris. It may simply be a matter of going out every spring and pruning the trees up so that you have six to ten feet of separation between those layers, with no low-hanging branches.”

Kuhr mentions something else, something that’s easily overlooked—decks.

“People don’t realize that pine needles and other junk accumulate under there,” said Kuhr. “What you want to have underneath a deck is rocks or bare soil. Put down a weed-control fabric, then cover it with wash rock or crush. If a fire starts in a tree, it can follow a root system. If it leads to a pile of duff (accumulated flammable debris), it can start a fire and burn that deck.” And, the building attached.

The three parts of the landscape contractor’s job—design, irrigation and maintenance—are the same three that go into becoming a firewise landscape contractor. All three of them need to work together in harmony, keeping fire prevention in the forefront. Remember them and implement them from a firewise point of view, and you’ll keep those home fires from burning.