Hello I’m Andrea Castillo and this is Seasonal, a newsletter that connects you to the Bay Area food system, one fruit and vegetable at a time. Seasonal comes out twice per month, and each post highlights the most interesting aspects of one seasonal fruit or vegetable grown and harvested around the Bay Area. Find me on Instagram at @seasonalbayarea or e-mail me at to share your feedback and suggestions, I’d love to hear from you. If you’d like to unsubscribe, click the gray unsubscribe link at the bottom of this post.

This week we nerd out on blueberries (available late April-August).

History plays an important role in shaping our food systems and blueberries have a long and unique history in North America. The commercial blueberries we eat today are nothing like the original varieties. To understand the blueberry’s transformation, we need to go back a couple hundred years after the end of the last glacial period.

going back in blueberry time

There are few fruits native to North America, and the blueberry is one of them. Wild blueberries, as well as cranberries and huckleberries, had been picked and enjoyed fresh and dried by indigenous peoples throughout eastern and northwestern North America for millennia. The indigenous peoples of North America co-evolved with several types of wild blueberries for nearly 11,000 years. It’s likely they first learned to take cues from animals as an indication it was safe to eat the fruit—maybe they thought: “if they eat it, I guess I’ll try that too.” Plus, the sweetness and rare blue-violet color of blueberries could have been particularly attractive to humans. 

Blue is a rare color in nature (fun random fact: when Homer composed The Odyssey, he never used the word blue to describe anything), and in the case of blueberries, it comes from the powerful antioxidant that makes a blueberry a super berry: anthocyanin. Anthocyanin can give fruit either a red or violet-blue color and, according to Dr. Henry Schreiber, a retired emeritus professor of chemistry at the Virginia Military Institute, the particular blends of anthocyanins in blueberries—delphinidin, cyanidin, petunidin, and peonidin glycosides—likely contribute to the berry’s rare blue color. Beyond color, anthocyanins help turn blueberry bushes into efficient photosynthesizers and boost the plant’s defense mechanism, helping it survive attacks and decreases in temperatures. For humans, preliminary research indicates that the antioxidant properties of anthocyanin in blueberries might boost our immune systems, protect our cardiovascular systems, and potentially help fight against cancer. Anthocyanin content in blueberries may even increase after fermentation, and I can’t wait to ferment blueberries at home (here’s the famous Noma recipe if you want to give it a shot)!

Anyway, the native peoples who enjoyed blueberries probably benefited tremendously from the excellent nutrition and health benefits of wild blueberries. For thousands of years, native peoples cultivated a deep knowledge and appreciation for this super berry. Blueberry traditions were passed down orally from generation to generation, including preservation methods: blueberries were sun-dried, smoked, or mixed with jerky and rendered animal fat to make an ancient energy bar (the buffalo meat and cranberry Oglala Lakota Tanka Bar made in South Dakota has kept the ancient tradition alive). Indigenous peoples also brewed medicinal tea made with blueberry leaves, flowers, stems, and roots, and used the berries to prepare natural dyes. The five-pointed star on the bottom of every blueberry held a strong spiritual significance for some tribes and the plant was considered a gift from the Great Spirit. The blueberry harvest was also an important time of the year for social interaction, reconnecting with relatives and friends on a seasonal basis, and sharing legends and stories.

10,900 years later

Indigenous peoples and blueberries have a long shared history, but our relationship with modern commercial blueberries is brand new. In 1911, a few years before the Spanish Flu and World War I wreaked havoc, Elizabeth White, whose family owned a cranberry farm in New Jersey, was determined to find a way to cultivate the delicious wild blueberries that grew on tall bushes by the pine forests in her property. Even though she loved eating the wild blueberries, she was frustrated they did not transport well and could not be commercialized. 

After learning how Dr. Frederick Colville, the Chief Botanist at the United States Department of Agriculture (USDA), had figured out that blueberries need acidic soil to thrive, Elizabeth decided to collaborate with him to find a way to cultivate blueberries in the barren, acidic soils of Whitesbog, New Jersey . After finding 100 of the best wild blueberry varieties, Elizabeth, Dr. Colville, and their team planted them and grew 300 more varieties from those originals. They kept meticulous track of every plant, carefully noting the strengths and weaknesses of each to find the best bush: genetically modifying the original to come up with a better variety for cultivation. In 1916, they had finally created and found The One and an industry was born. After surviving World War I, the Spanish Flu, and the Great Depression, the blueberry industry established its roots in New Jersey and has thrived ever since.

go west, young blueberry

If wild blueberries are wise elders, and Elizabeth’s east-coast commercial blueberries are the new kids on the block, then California blueberries are mere toddlers. The soil in California, unlike New Jersey, tends to tip toward the alkaline end of the pH scale and isn’t a great home for the acidity-seeking blueberry. California also lacks long periods of cool temperatures the blueberry bush requires to mature. But with a little human intervention, California-grown blueberries were bound to happen—it was just a matter of time and determination. By the end of the 20th century, the United States blueberry industry was well-established and Michigan, New Jersey, and Oregon led the nation in blueberry production. Everyone wanted blueberries and farmers in southern states like Florida and Texas wanted to grow them as well.

The USDA and the University of Florida eventually developed varieties that could thrive in warmer winters. Blueberries typically like 800 hours to chill in cool temperatures, but the southern hybrids thrive with just 500 to 150 hours of cool temperatures. The new, warmer climate blueberry bush enticed blueberry enthusiasts in California, and by the early 1990s, Californians had started cultivating these low-chill varieties. In the late 1990s, early adopter farmers like Kim and Mark at Triple Delight Blueberries saw an opportunity to diversify their raisin operation and began growing blueberries just south of Fresno. Thanks to researchers and farmers like Kim and Mark, we can now enjoy locally-grown blueberries, something that seemed unfathomable just 30 years ago.

The impossible, possible: a California-grown violet and blue dessert from Triple Delight farms.

blueberry delight… and an averted disaster

Triple Delight supplies blueberries to Bay Area farmers markets from late April through early July. Excited to try their tasty berries for the first time, I added them to the collective bulk purchasing I’ve been organizing for friends and family—enabling us to connect to our local food growers directly while minimizing trips to stores and markets. So, after calling in our order, with hand-sanitizer in my pocket and face mask securely in place, I picked up our bulk boxes from the Triple Delight stand at the farmers market. I brought along our functioning but half-broken hand cart and figured it wouldn’t be too difficult to wheel the stack of boxes for two blocks to the car. Just as I was leaving the farmers market, I ran over a bean-sized pebble with the cart and the topmost box ejected four pounds of blueberries across the pavement. 

My delight was turning into a disaster. Was I going to leave that pile of blueberries there? to waste? No. Of course not. Within seconds of assessing the damage, I decided to take a deep breath and go blueberry picking—off the asphalt. Bystanders who saw the spill couldn’t help because of social distancing, but still let me know they wished they could.

The initial feeling of helplessness was almost unbearable, but tiny acts of kindness transformed that helplessness into encouragement. One person disappeared for a few minutes and then returned to gift me a notepad she had grabbed from her car so I could use it as a scoop (thank you, stranger!). Even though I wasn’t reconnecting with relatives and friends, or sharing stories with them as the indigenous peoples used to during the harvest, the solidarity expressed by the strangers around me created a sense of real community over something as insignificant as spilled blueberries. “Harvesting” the last of my lost blueberries reminded me that there are caring helpers out there and we really are in this together.

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Andrea Castillo is a food nerd who always wants to know the what’s, how’s, when’s, and why’s of the food she eats.