San Francisco Orchid Society
Indoor Orchid Growing
in San Francisco's Fog Climate
The definitive guide to growing orchids in SF's unique marine layer climate — written by growers who've been doing it for decades.
SF's Climate Is Uniquely Suited to Orchids
San Francisco's climate is unlike any other major US city. The marine layer, cool summers, mild winters, and high ambient humidity create conditions that closely mimic the cloud forests where many orchid genera naturally grow. Growers in Phoenix, Miami, or Chicago spend significant money on climate control equipment to replicate what SF provides for free.
The key is understanding which aspects of SF's climate are assets (humidity, cool temperatures, temperature differential) and which require management (fog-reduced light, stagnant air in apartments). Once you understand these factors, orchid growing in SF becomes remarkably straightforward.
Understanding SF's Four Climate Factors
The Fog: Asset, Not Obstacle
SF's marine layer keeps humidity at 60–80% — ideal for most orchids. The challenge is stagnant air, not the moisture itself. A small fan solves this completely and prevents the rot that high humidity can cause without airflow.
Cool Summers Are a Feature
Most of SF rarely exceeds 65–70°F in summer. This is actually perfect for cool-growing orchids (Masdevallia, Dracula, Lepanthes) that are impossible to grow in warmer cities. Even Cymbidiums bloom more reliably here.
Light: The Real Challenge
The fog does reduce light intensity, especially in the Sunset and Richmond. East-facing windows maximize morning light before the fog rolls in. Supplemental LED grow lights are worth considering for north-facing apartments.
Microclimate Matters
The Sunset and Outer Richmond are foggier and cooler than Noe Valley or the Mission. Growers in sunnier neighborhoods can grow a wider range of warm-growing species. Know your neighborhood's microclimate.
Best Orchids for SF Apartments
- Phalaenopsis — thrives in any SF apartment, east or west facing
- Masdevallia — loves the cool fog, impossible to grow in most US cities
- Dracula — cloud-forest miniatures that prefer SF's summers to tropical heat
- Cymbidium — blooms spectacularly in SF's cool winters, great for patios
- Coelogyne — fragrant winter blooms, tolerates low light better than most
- Oncidium alliance — adaptable, rewarding, wide range of sizes