Adult Education

The Arnold Arboretum of Harvard University is a community resource for education, offering a variety of learning opportunities including lectures, classes, workshops, and tours of our living collections and historical landscape. Join us as we explore the biology and horticulture of woody plants, and delve into topics related to Earth’s biodiversity and evolutionary history, the environment, conservation biology, and key social issues associated with current science.

Featured Programs

Grafting Techniques for Ornamental Trees

Jack Alexander

Jack Alexander, Plant Propagator, Arnold Arboretum
Saturday, February 6, 9:00am–4:00pm
Location: Dana Greenhouse Classroom
Grafting is the technique of joining parts of plants in such a manner that they unite and continue their growth as one plant. It is a practical propagation method for the hobbyist, since it does not require special conditions or equipment. You will learn methods of grafting and practice making graft unions, both deciduous and evergreen trees and shrubs. The plants may include two- or five-needled pines and crabapples. (Simple aftercare will be required until planting out in late spring.) If you own pruning shears or a grafting knife, bring them to class. You must sign an assumption-of-risk-and-release form in order to practice the techniques taught in class. [Snow Date: Feb. 20]

Fee $90 member, $120 nonmember


Signs of a Warming World

Benjamin I Cook

Benjamin I. Cook, PhD, Research Scientist, NASA Goddard Institute for Space Studies and Lamont-Doherty Earth Observatory of Columbia University
1 Session: Thursday, February 25, 6:00–7:00pm
Location: Hunnewell Building
The temperature of the Earth is increasing, but what does that mean? And what effect will this have on people and ecosystems? Climate scientist Benjamin Cook will review some of the myriad indicators scientists monitor to understand the direction and pace of ongoing climate change, including changes in temperature, the cryosphere (snow, ice), and the hydrologic cycle (floods, droughts, sea level rise). He will discuss what these changes mean for species in the natural environment and our own societies. And he will touch on what we can expect in the future if we allow climate change to continue apace, and what options we may have to ameliorate, or adapt to, in a world that will be much warmer at the end of the 21st century than any time of the last several thousand years.
Fee Free members, students, and Tree Spotters; $5 nonmember
Register at or call 617-384-5277.


Pruning Shrubs

Jen Kettell

Jen Kettell, Horticultural Educator and Consultant
1 Session: Saturday, February 27, 10:00am–12:00pm
Location: Hunnewell Building
Knowing what and when to prune, and how to do so, are important as you manage your home landscape. Learn the basic techniques for pruning ornamental shrubs for optimum health and beauty. Jen Kettell, an ISA-certified arborist will address topics including pruning cuts and tools; thinning and reducing overgrown plants; shaping and encouraging new growth.
Fee $20 member, $30 nonmember
Register at or call 617-384-5277.

Massachusetts Certified Arborist and International Society of Arboriculture CEUs available.