Tyler Arboretum Staff Members

Meet our Senior Management Team

Mandy C. Santiago
Executive Director
Tel: (610) 566-9134
Extension: 207









Mandy is an accomplished nonprofit management and fundraising professional, deeply rooted in the Greater Philadelphia nonprofit community. She is a creative, strategic thinker, a good listener, and a nature-lover. A resident of Springfield, Delaware County, she is also a long-time member of the arboretum. Learn more here: https://www.tylerarboretum.org/new-executive-director/

Mike Karkowski
Director of Horticulture
Tel: (610) 566-9134
Extension: 222







Mike came to Tyler in 2004. He is responsible for the management of the Arboretum’s Horticulture Department, which maintains Tyler’s collections, plant records, natural areas, hiking trails, and historic buildings. Mike earned a Bachelor of Science from Purdue University in Landscape Horticulture and Design. His previous work includes Horticulturist and Director of Physical Plant and Grounds for The American College and Hardscape Consultant for a North Shore firm in the Chicagoland area. Mike enjoys building projects at home and church, building tree houses for his two children, and kayaking with family.

Amy Mawby
Director of Public Programs
Tel: (610) 566-9134
Extension: 301









Amy came to Tyler in 2013. She is responsible for the management of the Arboretum’s Education Department and oversees the coordination of volunteer services and Visitor Center staff and operations. Amy earned a Bachelor of Science from Cornell University and a Master of Science degree in Public Horticulture from the University of Delaware’s Longwood Graduate Program. She previously worked as Education Coordinator for Bowman’s Hill Wildflower Preserve and has interned at Morris Arboretum, the New York Botanical Garden, and Cornell Plantations. Amy is a bit of a shutterbug and enjoys nature photography.

Mary Beth Jackson
Director of Development
Tel: (610) 566-9134
Extension: 206










Mary Beth grew up playing outdoors in the farmlands of Tennessee and on the beaches of Florida’s Gulf coast. Many family vacations were adventures in camping, hiking, canoeing, and watching wildlife. Mary Beth earned her Bachelors of Arts in Psychology from Emory University and was thrilled to find Tyler when she moved to Pennsylvania. She sees Tyler as offering the complete package of outdoor experience with tree houses, historic trees, hiking trails, woods, and gardens, all on a Quaker family homestead.

She’s been fundraising for Tyler since 2011, becoming Director of Development in 2015. She’s worked in Development and Alumni Relations at Penn’s School of Nursing and School of Arts and Sciences. She’s also consulted for nonprofits in fundraising and campaign management.

Meet Our Staff Members

Listed by Department. T: 610-566-9134
To contact a member of Tyler staff by e-mail, please use the following format:
first initial, last name (no spaces) @tylerarboretum.org (Bill Smith would be: bsmith@tylerarboretum.org)


Beth Hoppe
Extension: 204


Gary Bloomer
Communication & Publications Manager
Extension: 267


Caitlin Anello
Membership & Annual Giving Manager
Extension: 208

Development Administrator
Extension: 209

Office Management

Kathryn Ombam
Office Manager
Extension: 200

Special Events

Brian Prato
Special Events Manager
Extension: 210

Public Programs 

Julia Lo Ehrhardt
Community Outreach Manager
Extension: 305

Liz Hornbach
Youth Programs Manager
Extension: 302

Joanne Landau
Extension: 303

Rebecca Silvey
School and Community Programs Coordinator
Extension: 306

Part-time Educator:

Shweta Arya
Early Childhood Educator


Mallory Smyth
Extension: 223

Alison Dame
Plant Recorder
Extension: 220

Austin Deputy
Extension: 221

Bess Trout
Extension: 223

Jerry O’Dell
Rhododendron Garden
Extension: 305, voice mail only

Jeff Wilson
Arboretum Manager
Extension: 219

Paul Strommer
Volunteer Apiarist

Vince DeJohn
Seasonal Gardener (mowing)

Visitor Center

Brian Kirk
Visitor Center Lead Associate
Extension: 212

Sara Painter
Visitor Center Associate
Extension: 212

Sarah Spaulding
Visitor Center Associate
Extension: 212

Nicole Sipple
Visitor Center Associate
Extension: 212


Julia Lo Ehrhardt
Community Outreach Manager
Extension: 305


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