Photo by Mark Weaner

Presenters: Jack Ahern & Larry Weaner

Spontaneously occurring plants and plant communities are typically either eliminated or neglected. Our two presenters will discuss more nuanced and selective approaches for managing the  mix of native and exotic species that typically colonize our urban and suburban landscapes.

Part 1: Jack Ahern will discuss prevailing and alternative attitudes towards invasive exotic plants. He will also discuss ways to influence spontaneous vegetation in a manner that is both desirable and attainable including soil/substrate issues, selective removal methods, adaptive management, and managing public expectations.

Part 2: Larry Weaner will show how an understanding of the life cycles, proliferation strategies, and environmental vulnerabilities of plants, desirable and undesirable, can help practitioners more effectively influence the vegetative trajectory of spontaneous plant assemblages. 

Date & Time: Friday, March 31, 2023, 1:00 - 4:30 PM EDT
-The session will be recorded and viewable to registrants for 3 months after the live session date.

Location: Virtual

Fee: $88
-Students please email verification of student status to for discount code.
-Both free Student Scholarships have been awarded for this session. Applications no longer accepted.

Event Category: Professional

CEUs: APLD (3), LA CES (3), & NOFA (3)
See here for details & instructions

Register by: 3 months after the live session date



Registration is open and recording is viewable for 3 months after the live session date. Students please email verification of student status to for discount code.


Jack Ahern, PhD, FASLA, is emeritus professor of landscape architecture at the University of Massachusetts Amherst and Fellow of the American Society of Landscape Architects. He researches and writes about how ecological knowledge and theory can be applied in landscape design and management – at multiple scales and in diverse contexts – from cities to forests. His latest book is Design with Nature on Cape Cod (UMass Press 2022).

Larry Weaner, FAPLD, founded Larry Weaner Landscape Associates in 1982 and established NDAL in 1990. He is nationally recognized for combining expertise in horticulture, landscape design, and ecological restoration. His book Garden Revolution: How Our Landscapes Can Be a Source of Environmental Change (Timber Press 2016) received an American Horticultural Society (AHS) Book Award in 2017. In 2021 he received the AHS Landscape Design Award and the APLD Award of Distinction.
Photo by Kim Sokoloff


  • Recording: Will this course be recorded for me to view later? Do I have to attend the live session in order to access the recording?

    The entire course will be recorded and available (not downloadable) to all registrants after the live session ends for three (3) months. If you are registered, you do not need to attend the live session in order to access the recording.

  • Recording: Can I purchase only the recording later?

    You can register for 3 months past the live session date, and access the materials - including the recording - until that point.

  • Webinar Platform: Which webinar platform will the live session be held on?

    Zoom Webinar. Please make sure to download the Zoom application ( and download the latest Zoom update if needed prior to the live course. We recommend that you join at least 5-10 minutes prior to the start time. The instructor will use PowerPoint presentations. *If you have any technical difficulties during the session and need to contact us, please email Sara Weaner, NDAL Executive Director, at instead of calling.*

  • Continuing Education Units (CEUs): How do I receive the CEUs?

    As this is considered a live course, those seeking LA CES CEUs must watch the session and complete the quiz on the Portal by *two weeks* after the live session date. Ensure that your Portal profile indicates ASLA/LACES under the CEU section and email if you make any changes to your profile CEU section. You will then receive an email with your completion certificate within 3-4 weeks. || For APLD & NOFA CEUs, please self-report to those organizations using your registration confirmation email. If you need a completion certificate and are not seeking LA CES CEUs, please write "need certificate" in your Portal profile CEU section and email letting us know you updated it.