Cora Hartshorn Arboretum is opening its woodland grounds for a guided meditation session timed to the fall equinox on Sept. 20.

The event, called "Among the Birds: Breath, Presence, & Guided Meditation," runs from 10:30 to 11 a.m. at the arboretum's home at 324 Forest Drive South in Short Hills. Tickets cost $15 per person or $20 for two.

Space is limited.

Diana of Happy Heart Yoga Shala will lead the half-hour session. She has studied with New York City-based yoga teacher Sri Dharma Mittra for more than 20 years and has led classes and retreats in the United States and abroad since 2012, according to Patch. Organizers describe her classes as welcoming, joyful and accessible.

The arboretum's event page frames the morning as a chance to celebrate the fall equinox among the sanctuary's sights and sounds. Participants are invited to settle into birdsong and then explore the forest along the arboretum's 3 miles of trails, which wind through 16.45 acres of woodlands.

Chairs and mats are provided. Participants can request a mat when registering. The program is recommended for ages 15 and older, though organizers say everyone is welcome.

The arboretum, a nonprofit tracing its roots to a 1923 land gift from Stewart Hartshorn to his daughter Cora, hosts school field trips, scout programs, family events, adult workshops and summer camp throughout the year. The meditation session adds a wellness offering to that lineup.

Advance registration is encouraged. Tickets were listed as available on the arboretum's website as of Aug. 24. Residents can register at hartshornarboretum.org or call 973-376-3587.

For a full list of fall programs at the arboretum, check the events calendar at hartshornarboretum.org.