If you spot a large tree in San Diego’s Balboa Park, there’s a good chance it was planted by Kate Sessions.

The pioneer botanist finalized a deal with San Diego on this week in 1892 to lease a plot of city parkland for a nursery. In exchange, she agreed to plant 100 trees a year in the park, and donated many more for planting around the city. Thanks in no small part to her efforts, Balboa Park became San Diego’s centerpiece, a 1,200-acre horticulture oasis created out of a scrub-filled mesa.

In a 1995 profile in San Diego Reader, people who knew Sessions recalled her as a lonely figure who was wholly consumed by her love of plants. She worked 12-hour days, taking only two vacations in 60 years. When it grew too dark to garden, she would read botany books in her home office, lamp light illuminating her face. Her uniform: a twill skirt, felt hat pulled low, and men’s boots that she would use to kick marks in the dirt for plantings.

Private feelings, Sessions once said, were “a waste of time.”

While she maintained a network of friends, Sessions never married, rejecting at least two proposals, and had no children. In a letter to a friend, she said her flowers were her children — the banana palms, twisted junipers, jacarandas, and bougainvillea vines that brought her world to life.

In the fall of 1939, a fall in the garden put Sessions in the hospital. Among her final acts was to summon San Diego’s city planner to her deathbed so she could tell him what ought to be planted alongside a new stretch of the 5 Freeway. She died at 82.

The local historian Clare Crane was asked during a 1978 KPBS radio program to sum up Sessions’ place in the story of San Diego. She recalled seeing a plaque during a trip to Florence that described the city itself as a memorial to Michelangelo. The same is true of Sessions, she said: “If you would see her memorial look around you.”

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