The Science of California’s ‘Super Bloom,’ Visible From Space

After a particularly wet and snowy winter, California’s hillsides are exploding with patches of vibrant orange, red and purple wildflowers so large they can be seen from space—an event many call a “super bloom.” 

A super bloom is “a wonderful natural phenomenon where many annual wildflowers all bloom simultaneously,” Naomi Fraga, director of conservation programs at the California Botanic Garden, tells the Washington Post’s Allyson Chiu and Naema Ahmed. “You have a great diversity, an abundance of many different wildflower species, all flowering, creating bright patches of color on the landscape where they become the dominant feature.” 

Such a spectacle can occur when a wet year follows several consecutive dry years. Wildflower seeds collect in the soil when it’s dry, waiting for just the right conditions to sprout. Well-timed rain can lead the previously dormant seeds to germinate at once. And this year, the Golden State has experienced this exact scenario—before its record-breaking precipitation this winter, California had faced three of its driest years on record, per the Post. 

Beyond rainfall, wildfires or grazing could also spur a super bloom, as these events can cut down on the non-native grasses that might otherwise outcompete the flowers.

During the most breathtaking super blooms, one type of wildflower will give way to another as the weeks go by, producing subsequent waves of color. “Because they evolved together to bloom at slightly different times, they’re sharing those resources without crowding each other out,” Kate Rabuck, deputy director of the Sonoma Botanical Garden, tells the San Francisco Chronicle’s Jack Lee.

The vibrant colors of a superbloom of wildflowers in California were on full display in satellite imagery released by Maxar Technologies. pic.twitter.com/IFri3K6WXZ

— CBS Sunday Morning (@CBSSunday) April 17, 2023

Historically, super blooms would brighten a given area about once per decade. But recently, climate change is making these events more unpredictable, writes Jamie Ferrell for Secret San Francisco. In Southern California’s Anza-Borrego Desert, for example, researchers counted ten separate super blooms in 40 years. 

Additionally, severe droughts can increase the time between these vibrant phenomena and parch the perennial plants that wildflowers rely on. These native shrubs would ordinarily act as shelter for wildflower seedlings that are beginning to grow, per the Chronicle.

Amid these threats to the blossoms’ splendor, ecologists urge visitors to avoid damaging the flowers. The colorful vistas have attracted swarms of tourists in past years, putting strain on the land and local resources. During the last wildflower super bloom in 2019, selfie-taking visitors flocked to Walker Canyon in Lake Elsinore, trampling flowers, backing up roads for hours and parking cars illegally along the freeway. In Antelope Valley, California, one couple even landed a helicopter in the middle of a poppy field.

“In 2019, the poppy bloom here in Walker Canyon became a local, state, national and even international phenomenon,” Lake Elsinore Mayor Natasha Johnson said at a news conference. “Tens of thousands of people—as many as 100,000 in a weekend, Disneyland-sized crowds—were seeking to experience nature. … Many came unprepared, and they placed an undue burden on the emergency responders.” 

This year, officials announced Walker Canyon would be closed for “safety reasons and to help protect sensitive habitat.”

Beyond their beauty, wildflowers are a food source for herbivores, and they help support insects and pollinators, improve soil health and prevent erosion.

“Wildflowers are one of the most important resources we have to ensure the resilience of California’s grasslands,” Valerie Eviner, an ecologist at the University of California, Davis, says in a statement. “They are our emergency first responders when grasses fail—whether due to fire, drought or soil disturbance.”

Margaret Osborne | | READ MORE

Margaret Osborne is a freelance journalist based in the southwestern U.S. Her work has appeared in the Sag Harbor Express and has aired on WSHU Public Radio.