Rippling in the wind, waist-high green and brown grasses surrounded Michelle Halbur on a slope at Pepperwood Preserve in the Mayacamas Mountains north of Santa Rosa.
“I feel like I’m in the ocean,” the preserve ecologist said as she documented the resurgence of grasses, up to more than 5 feet tall, in an area blackened by a controlled burn a year ago.
But where Halbur marvels at fertile hillside, uneasy North Bay residents and firefighters now face a bumper crop of wild grass — fostered by drought-squelching rains — that threaten to fuel another disastrous season of wildfires in California.
Winter’s liquid largesse, which banished the five-year drought in California, turns to a liability as temperatures rise and — as the late Kate Wolf, a former Sonoma County resident, sang — “the hills turn brown in the summertime.”
Already statewide, more than 1,100 fires since the start of the year have burned more than double the swath of territory torched last year at this time, according to Cal Fire. In Sonoma County, a small wildland blaze last month caught the attention of local firefighters, who saw it as a potential harbinger of a bad season.
Windblown embers from a house fire east of Cloverdale crossed a road and ignited the grass on May 24, charring 5 acres before firefighters corralled the flames.
“It shows you the potential is there,” Cloverdale Fire Battalion Chief Rick Blackmon said. “Two or three months from now, it would have been a whole different story. The hills are starting to dry up.”
Most fires start in grass, known to firefighters as a “fine fuel” because it readily ignites and spreads flames quickly. Thicker grass burns hotter, becoming harder for firefighters to put out and increasing the chance of ground-level flames climbing into treetops and triggering a forest fire.
Pepperwood was scorched by the Hanly fire that roared from Calistoga to the edge of Santa Rosa in 1964, still Sonoma County’s largest fire. Today the preserve, dedicated to conservation science, protects 900 acres of grasslands with selective cattle grazing and controlled burns, while thinning its oak and fir woodlands.
But in recent years, Sonoma’s wildfire experience pales compared to southern Lake County, where a trio of fires in the summer and fall of 2015 wreaked havoc over 267 square miles — about one-fifth of the county’s land.
In the past five years, 24 Lake County wildfires have covered nearly 190,000 acres, while cooler, foggier Sonoma County had just six fires covering 5,500 acres, according to Cal Fire records for blazes of 10 acres or more from 2012-16.
The National Interagency Fire Center based in Boise, Idaho, noted last week that California’s “robust fine fuel crop” is drying now and will be “fully cured” by late July or August, elevating the threat of large grass and brush fires.
But concerns are already rising as fires are breaking out, mostly in the Central Valley and Southland, at a torrid pace this year.
Cal Fire’s latest tally counts 1,142 fires that have covered 15,406 acres since Jan. 1 in areas under the state agency’s jurisdiction, more than twice the swath of the 981 wildfires over 6,286 acres in the same period of 2016 and well above the five-year average of 11,046 acres.