10/31/2026
Some fascinating tree history for you this morning.
In 1892, a woman persuaded San Diego to give her access to 30 acres of public land. She wasn't planning to build houses or develop a business district. She wanted to grow trees.
Katherine Olivia Sessions offered the city an extraordinary bargain. In exchange for using the land as a nursery, she would plant 100 trees annually in the park and supply another 300 for streets, schools, and public spaces.
It was the beginning of a transformation that would change San Diego's appearance.
Born in San Francisco in 1857, Sessions had graduated from the University of California in 1881, when women pursuing scientific careers still faced considerable obstacles. Her senior essay explored the natural sciences as a field of employment for women.
After moving to San Diego, she abandoned teaching for horticulture, eventually establishing her own nursery business.
The city's dry hills and sparse vegetation presented an enormous challenge. Sessions began experimenting with plants from around the world, discovering which species could flourish in Southern California's Mediterranean climate.
She cultivated palms, pines, cypress, eucalyptus, jacarandas, and countless ornamental plants. Her experimental nursery eventually contained thousands of specimens.
But her ambitions extended beyond one park. Sessions encouraged residents to plant trees, helped beautify school grounds, and worked with civic leaders to create green public spaces.
She also became an internationally respected horticulturist, exchanging knowledge and specimens with botanists around the world.
In 1939, at 81, she became the first woman awarded the prestigious Frank N. Meyer Medal for her contributions to plant introduction.
Sessions never married or had children. In a letter to fellow botanist Alice Eastwood, she affectionately described their plants as their children, explaining that she grew them while Eastwood named them.
She died in 1940, aged 82, after spending more than half a century cultivating the city she loved.
Today, Balboa Park is celebrated for its magnificent gardens and mature trees. A bronze statue honors the woman who helped make them possible.
San Diego remembers her as the Mother of Balboa Park.
