Fall is a season tailored for learning at the Arnold Arboretum. Explore global change in the New England forest, join a Mushroom Hunt beneath the tree canopy, or experience the science of fall leaf color with hands-on experiments and a walk among turning leaves. Guided highlights tours, Peters Hill and Explorers Garden walks, birding and owl spotting, and forest bathing offer something for every curiosity—whether you’re drawn to ecology, wildlife, history, or personal well-being. This fall also brings Living Connections: The Arnold Arboretum and Korea, a new exhibition pairing plants, photographs, and archival materials to tell a cross-continental story of exploration and collaboration. Many programs are open to all and always free, but some of our most in-depth offerings—including behind-the-scenes spotlights and exhibit preview receptions—are reserved for members. Join today to gain access to our full complement of learning opportunities this fall and receive early access to our program guide in seasons to come.

Step into the Arboretum after hours on Thursday, September 24, for our newest celebration: Afterglow at the Arnold. As the sun sets over Bussey Hill, the Explorers Garden will transform into an illuminated gallery of botanical wonders, where trees are your ambassadors for a global journey of discovery. The event begins at 5:30pm with a VIP Experience that includes mingling with Arboretum experts, introductions to charismatic plants from around the world, and delicious bites and drinks in the garden. VIP ticket holders are encouraged to stay for the Afterparty—co-presented with the Young Friends at the Arnold—beginning at 7:30pm and featuring remarks from our director, drinks and passed food, and music and dancing into the night. Proceeds from Afterglow support the Arboretum’s role as a free public park, research museum, and community resource. Arboretum members receive discounts on Afterglow tickets and enjoy a host of great benefits all year long—consider becoming a member to deepen your connection to the Arboretum and its plants.

Goldenrod yellow, nettle green, madder pink—many of the plants you pass on your Arboretum walk have long histories as natural dyes. At this drop-in program on the Hunnewell Lawn, fiber artist Maggie Ruth Haaland will introduce you to the age old art of plant-based fabric dyeing, using species grown right here at the Arboretum. Wander over anytime between 12:00 and 3:00pm on August 23 to watch color bloom in steaming dye pots, learn how roots, leaves, and flowers release their hues, and dip a piece of fabric into the bath to create your own naturally dyed keepsake. Fabric and dye baths are provided, and all ages are welcome—no registration required. Whether you stay for a few minutes or a full afternoon, you’ll leave seeing the landscape differently: not just as a “museum of trees,” but as a living palette of color, craft, and history.

If you’ve ever wandered among the bald cypresses in our landscape, perhaps you’re familiar with one of our collection’s quiet mysteries: the strange, woody knobs at their bases known as cypress knees. In a recent video edition of his Posts from the Collections, Director William (Ned) Friedman invites visitors to linger among these curious structures—root outgrowths that look like sentries, candles, or a gathering of small woodland spirits. As Ned confesses, no one is entirely sure what cypress knees do. Are they helping roots breathe in soggy soil, anchoring the tree in floods, or simply an evolutionary whimsy? Ned walks us through the latest science, points out subtle details in their form and arrangement, and reminds us how much wonder lives in things we can’t fully explain. Watch “The Tree’s Knees,” then visit the Arboretum’s bald cypresses yourself at Dawson Pond, in the conifer collection, and on Peters Hill. You may never look at the forest floor the same way again.

All images from the Arnold Arboretum © 2026 President and Fellows of Harvard College.