Updated 11:30 a.m. Monday, May 15

If you’re in the Bay Area, you might have noticed that trees have been splendidly in bloom around the region since early February. Vibrant wildflowers are popping up around California, a sight of bursting color that many look forward to every year — as much as they look forward to striking-looking invasive species that carpet the hillsides.

Spring is in the air in a big way, thanks to the abundant rain we’ve received so far. So you might be wondering: Will there be a “super bloom” this year? Where are the best places to see wildflower blooms in the Bay Area? And what’s the science behind the seasonality of plant blooms?

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What are super blooms, and can we see them in the Bay Area?

Wildflower lovers have no doubt been thrilled by recent images of Southern California super blooms visible from space.

California is the most biologically diverse state in the country, home to about 8,000 species of plants. Over 2,300 of those are wildflowers, says Cameron Barrows, conservation ecologist at the Center for Conservation Biology at UC Riverside.

“Super bloom,” he says, is not a scientific term, and is mainly used by the media to describe incredible bloom events that are not very common, when many different species of wildflowers bloom at the same time. “There might be anywhere that’s 50 to 100 different species in bloom during a super bloom event,” Barrows said.

The right amount of rain and temperature set the stage for a super bloom. “I refer to this as sort of a global ‘Goldilocks scenario’ where [it’s] not too much rain, not too little rain — not too hot, not too cold,” said Barrow. “When it is just right, then lots and lots of species will bloom at the same time.”

The best blooms happen when we have a wet year followed by a strong drought, according to Richard Minnich, professor at the Department of Earth and Planetary Sciences at UC Riverside. He says that the drought suppresses invasive species or annual grasses, leaving room for the wildflowers to take off.

Minnich cites the super bloom event of 2005 in Death Valley as a great example of this, saying it was “after one of the wettest winters we would ever see, and it also followed some dry weather.”

This month, sight seekers have been flocking to see the latest blooms in the state. But while these new colors are striking, we’re still not seeing a California super bloom of the magnitude seen in 2005 or the colorful super bloom explosion of 2019, says Barrows.

That’s because this latest desert wildflower bloom “has been good but confined to desert washes where rainfall runoff has been concentrated,” said Cameron. “Beyond the boundaries of the washes very few wildflowers have bloomed, and the high temperatures are now wringing all remaining moisture from the desert sands.”

We’ve had exceptional rainfall so far in 2023, occurring earlier than in previous years. This encourages invasive plants to germinate earlier, taking over the opportunity for native wildflowers to bloom. And ideally, for a true super bloom to occur, we’d need that “Goldilocks” balance to ensure that invasive plants don’t dominate and the native plants can “complete their entire life cycle,” Barrows said.

We’ve also had very cold weather these past few months, extending the bloom period to later in the spring, says Minnich.

This year, wildflowers will “bloom later into the spring,” he said. “Once they start they’ll last longer because the ground is obviously really wet.”

Where and when can you see blooms in the Bay Area?

If you’re planning to head out on a trail to enjoy these wildflower blooms, be sure to respect the landscape and stay on designated trails. Do not trample or pick any flowers, and pack out anything you pack in. And be sure to check the park’s website for any closures or updates on current conditions. It’s also worth noting that if you have allergies, be sure to be prepared with medicine, and take preventative measures before embarking on your wildflower journey.

Be aware that “there’s this entire ecosystem that the flowers are helping to support,” urged Barrows. He says that when you damage the wildflowers, “you are then not only impacting the bees and the butterflies and the hummingbirds and the animals that eat the flowers and eat the seeds and so forth,” but also the opportunity for future super blooms.

You might be able to spot wildflowers or colorful invasive plants in the locations mentioned in the 2019 KQED guide “Where to See a ‘Super Bloom’ in the Bay Area.” Some of the locations recommended:

• Point Reyes National Seashore
• Berkeley Hills
• Mount Davidson
• Russian Ridge Preserve

If you’re in San Francisco, The San Francisco Standard recommends the following wildflower spotting opportunities:

• Balboa Natural Area
• Bernal Hill
• Corona Heights
• Grandview Park
• Tank Hill
• John McLaren Park

Other wildflower spots recommended on AllTrails include Land’s End Trail, Batteries to Bluffs Trail in the Presidio, and Glen Canyon Park.

In the East Bay, you can find wildflowers at Tilden Regional Park, Coyote Hills Regional Park, and Sunol Wildnerness Regional Preserve.

Here are a number of options in the South Bay and Peninsula:

Santa Clara County Parks officials are expecting a display of wildflowers this spring that is expected to last until May. You can find the hot spots for the upcoming wildflower array using their online mapping system. The dashboard allows people to view the trails in Santa Clara County and summarize statistics about them. The recommended county parks to view the wildflowers are:

• Stile Ranch Trail at Santa Teresa County Park
• Calero County Park
• Coyote Lake Harvey Bear County Park
• Almaden Quicksilver County Park
• Joseph D. Grant County Park
• Uvas Canyon County Park

Other parks in Santa Clara County:

• Henry W. Coe State Park
• Mount Hamilton
• Rancho Cañada del Oro Open Space Preserve
• Coyote Valley Open Space Preserve

San Mateo County:

• Mori Point, Pacifica
• San Bruno Mountain Park
• Edgewood Park and Natural Preserve
• Pulgas Ridge Reserve
• Alum Rock Park

Here are a few more recommendations on where to see colorful blooms, from California State Parks:

Mount Tamalpais State Park, Marin County

On Coast View Trail near Pantoll, you’ll be able to see some wildflowers like the Pacific hound’s tongue, common starlily and dwarf checkermallow in February and March. Later in the spring in April and May, you can spot species like the narrowleaf mule’s ear, lupine, Ithuriel’s spear, blue dicks, California poppy and Western blue-eyed grass.

China Camp State Park, Marin County

In March, you can see wildflowers like the Warrior’s plume, shooting star, milkmaids, laceleaf sanicle and sun cups on the Shoreline Trail. In April and May, you might be able to see California poppy, narrowleaf mule’s ear, yellow mariposa lily, Ithuriel’s spear and Douglas iris.

Trione-Annadel State Park, Sonoma County

In March, look for buttercup, shooting star, purple larkspur, common starlily, checker lily and Pacific hound’s tongue on Cobblestone Trail. April and May bring yellow mariposa lily, ookow, red larkspur and purple Chinese houses.

Sugarloaf Ridge State Park, Sonoma County

On Lower Bald Mountain Trail, in February and March, look for Pacific hound’s tongue, red maids, baby blue eyes, checker lily and more. April and May bring whispering bells (a fire follower), popcorn flowers, Diogenes’ lantern, blue dicks, lupine and California poppy.

Phenology, climate change and seasonal change

Phenology is the study of cycles and seasons in nature, and people have been studying how plants around the world respond to seasonal changes — including blooms — for thousands of years.

Phenological data for the cherry blossom tree, for example, dates back to the ninth century in Kyoto, Japan. Back in the 800s, people weren’t necessarily collecting this data for the sole purpose of scientific evidence — but for the sake of cherry blossom party planning.

Celebrating cherry blossoms was “a really big event in Japan then,” said Libby Elwood, ecologist and director of education, outreach, diversity and inclusion and global collaborations at iDigBio on a recent episode of Forum about seasonal change. “And it continues to be as it is in many cities and places around the world.”

Cherry trees blossom for a very short period of time, making the peak flowering stage a critical data point in understanding the physiological stage of the tree. It’s also the most well-documented data in phenology, Elwood says.

In the Bay Area, you can see cherry blossom trees blooming now at the Japanese Tea Garden in San Francisco, lasting hopefully until about early April. And the official Northern California Cherry Blossom Festival, an annual event celebrating spring and Japanese culture, will be happening April 8–16 in San Francisco’s Japantown.

Plants start blooming when there’s a change in temperature, light and precipitation. As our climate gets warmer, the blooms, along with other stages in the plant life cycle, start earlier, Elwood says. “Modern climate change studies and phenology are ways to see how temperature and climate is impacting plants and animals,” said Elwood.

As plants begin to bloom earlier, the hope is that insects — the pollinators — also start coming out at the same time. As insects become more active earlier in the spring, the birds may also sync up. “You have this relationship between the plants and their pollinators and then between birds and their food source,” said Elwood. “And you hope that those are all in sync.”

Blooms can vary from block to block in your neighborhood, depending on where the plant is. Local variabilities like streetlights, radiation heat coming off buildings and wind protection from buildings can be a few reasons for these varied blooms in the city, according to Elwood. “There is definitely a lot of that sort of microclimate happening,” said Elwood.

Tracking invasive species and animals over time

If you’ve seen plants or wildflowers that you don’t recognize and would like to learn more about them, Elwood recommends using the community science app iNaturalist to upload your photo. Chances are there might be a match on the app that helps you find your answer.

The data that is fed into apps like iNaturalist is used by experts in the field of phenology to track invasive species or animals, in places where they weren’t seen before. Certain plants and animals might shift to locations with their preferred temperatures and precipitation levels, and apps like this can help track those changes.

“As the climate changes, certain plants and animals might be showing up where they weren’t historically,” said Elwood.

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