From the website:

Join us for a weekend full of whimsy this autumn as the Garden is transformed into a realm of imagination and wonder. Celebrate the magic of the season while enjoying brews and local fare at our beer garden, browse our magical marketplace, and discover an otherworldly dreamscape of unusual plants through our Stranger Plants exhibit along the way. This weekend features fantastical crafts, workshops, and entertainment for all ages. Come dressed up as your favorite fantasy being!

The art sale will be happening in the Resevoir room.

https://nebg.org/weekend-of-wonder/