What is the best place to buy tree-like house plants in San Francisco?

I can’t help you with a specific store but might suggest a medium-sized banana tree. They grow really rapidly and yet, if purchased fairly small, can be hauled up several flights of stairs without herniated the carriers’ discs.

Do any of the uni’s have arboretums? Often you can find unsprayed specimen there.

I had a yucca plant that got to about 6 foot tall. And it didn’t need a lot of maintenance.

edit: herniating.

I forgot to mention that a banana tree can grow up to 27 feet.

I use Cliftons online nursery in Porterville, CA they have wonderful dwarf trees that can be shipped. So far I have 1 dwarf avocado, a dwarf nectarine and a macadamia nut tree from them. This year I plan on buying the dwarf banana tree they sell. Best of luck to you. I have also purchased from 7servant7 in Gereta Louisiana for my tomato tree seeds.