Expect a calm, hour-long vinyasa or gentle flow class set among seasonal plant displays, with the city skyline often visible. Classes happen rain or shine (they'll move under cover or cancel only in serious weather). In summer the gardens are lush and green; spring brings tulips and cherry blossoms; fall offers golden foliage and fewer crowds. Winter sessions are rare but can feel magical with snow on the ground if you're bundled up. Mornings tend to be best—cooler, quieter, and the light is nicer for photos if that's your thing.
Expect to pay around $25–$40 for a drop-in class including garden admission. Some multi-class packages or member discounts bring it down, but tourists usually pay full rate. Bring your own mat unless the organizer provides them (many do for an extra fee). The experience is pleasant and low-key: birds, occasional planes overhead, and the scent of flowers or herbs depending on what's blooming. It's more restorative than athletic.
Pick early morning weekend classes in late spring or early fall when the weather is most reliable and crowds are manageable. Skip peak summer midday sessions—they get hot and the gardens fill with non-yoga visitors. If you're short on time, just do a regular garden visit instead; the yoga itself is nice but not life-changing.