Methodology
About this little app
SF Bloomwalk is a love letter to San Francisco's street trees. It's a walking-only "transit" tool that nudges you past whatever is probably blooming today.
Where the trees come from
The city of San Francisco publishes a complete Street Tree List through DataSF — every documented street tree, with species and coordinates. We query it on the fly, scoped to a small box around your route, so you always see fresh data.
How we guess 'flowering'
We keep a hand-curated bloom calendar for around thirty common SF street species — cherries, magnolias, jacaranda, tibouchina, callistemon, lagerstroemia, and friends. Each species gets a peak window and a shoulder window of months, drawn from horticultural references (SF Botanical Garden, Friends of the Urban Forest, Calflora) and from a lot of walking.
How the routing works
Walking directions come from OSRM (foot profile) on the public demo server. Map tiles are OpenStreetMap. Geocoding is Nominatim. No API keys are required and nothing about your route leaves your browser except the addresses you type.
What it isn't
It is not a guarantee. Trees skip years; the weather plays tricks; a tree the city says is one species can absolutely be another. If you spot something gorgeous, take the long way home and tell a friend.
Built with TanStack Start, Leaflet, and a stack of field guides.