California's Superbloom

...the deserts and grasslands of Southern California come alive with a profusion of wild flowers so vast they cover hundreds of square miles. So vast they can be  easily tracked from space . These rare natural flowering events, which last for up to two months, are informally called " superblooms ."

Superblooms are rare because getting exactly the right conditions is hard. You need rain, at least 200% of normal. But just as importantly the rain needs to come at the right times. Even more so, the rain needs to be spread evenly across the winter rainy season, which runs October to April. Any cold snaps or prolonged dry spells will stop the flowers. Any torrential downpours can wash away the seeds. Any early spring heatwaves and it'll fizzle. All of these conditions aligning only happens, on average, about once a decade in Southern California.

I was surprised to learn that there really is  no hard-and-fast biological category  for a superbloom. It is one simply if we call it one; they are just years when there are way more flowers than normal. Way, way more flowers. As we can see in the satellite images below, the change in the land is astonishing.

The native flower seeds can lay dormant for years waiting until the right conditions align. And when then do, it's a spectacle unlike anything you've seen and stretches to the horizon.

California is a huge place, and saying “superblooms happen in the desert” is neither helpful nor entirely accurate; they can occur in many grassland and  chaparral biomes , as well as in the desert. The blooms start first in the dry and warm Sonoran Desert near the Mexican border in February and over the next three months roll north to the grass hills of Central California.

Each of the four locations above has its own unique character and showcases different species of flowers. What they all have in common is an average 4 to 11 inches of rain per year, creating desert or semi-desert conditions and treeless landscapes.

SoCal has a distinct wet/dry climate in which almost all of the rain for the year falls in a few months over the winter. In a good year the rains will start in late October and last until early April. In a bad year, the rains might not start until January and are hit or miss after that. The land remains dry and the flowers stay dormant. In other years we may get one or two big storms which bring lots of rain all at once, but the flowers need a gentle soaking over many months to really shine.

Because of the geographic diversity and microclimates of the region, using climate data from airports 50–100 miles away wouldn't cut it. I needed data collected as close as possible to the favored bloom locations to learn what was going on.

We all know superblooms need rain, but I wanted to dig a bit deeper into the data. Using annual rainfall totals wouldn't work since those are reported by the calendar year, not by the rain season year (which straddles New Years). I would have to get monthly data and aggregate the data to see how superbloom years differ from other years.

Fortunately I found great monthly precipitation totals from  NOAA's Climate Data Online  for Anza-Borrego State Park and Lake Elsinore beside Walker Canyon, and here's what they show.

As seen above it takes about 200% normal rainfall to create ideal conditions for a superbloom. Worryingly, the very obvious five-year drought from 2011 to 2016 is a sign of climate changes to come. If that trend continues—and scientists suspect it most certainly will—it could mean fewer superblooms and possible degradation of the biomes which support these plant communities.

Or, this is why we can’t have nice things.

One challenge is that people want to experience these superblooms in person. I certainly do, I 100% get it. But we have a tendency of loving things to death, especially if they’re an easy drive away. With a social-media hungry population of 20 million living in Southern California looking for movie-perfect shots, the last few superblooms have seen an exponential increase in visitors.

In March 2019 “ Disneyland-sized crowds ” descended on Walker Canyon area near Lake Elsinore. The majority of visitors tried to stick to the trails and avoid picking or trampling the flowers, but it was only a matter of time before things got out of hand. With motorists literally stopped on Interstate 15 to get access to the hills,  the police were forced to close the areas . It wasn’t long before  social media shaming   followed (and also  here ). 

As I write this in January of 2021, it's clear this year is well below average for rainfall and won't be a superbloom year. It is impossible to know months or years in advance when the next big one will be, but I am delighted by the many crowd-sourced wildflower  tracking services  which have been created to help photographers, hikers, and nature fans find the best spots every year. Through Twitter many of the National Parks, State Parks, and Bureau of Land Management teams share important tips on the latest spring-time blooms. Just because the entirety of SoCal isn't having a superbloom doesn't mean there aren't still smaller flower displays every year. You just have to look a bit harder to find them.

By all means enjoy the beauty of what SoCal has to offer, but please stay on trails and don't endanger motorists by parking illegally to get the perfect photo. And never, ever pick wildflowers or lay down on them, it is both illegal and destructive. Getting likes for instagram isn't as important as protecting these remarkable landscapes.

Can't get enough of the superbloom? Learn more below.