Log in

Update from 2019 AZH Internship Award recipient - Columbus Zoo

February 16, 2020 12:43 PM | Anonymous member (Administrator)

2019 AZH Internship Grant Project


The 2019 AZH internship program fund was used in support of the Project and Site Design Internship at the Columbus Zoo and Aquarium. It funded a special project that represented a joint effort between the intern and several departments of the Columbus Zoo and Aquarium - including Planning & Design, Horticulture, Animal Nutrition (Browse Program), Animal Health, and Animal Care.

Project Background

The Columbus Zoo is structured such that Capital Improvement Projects are managed by the Planning and Design Department. Once a project is completed, installed landscapes are managed by the Horticulture Department. The Horticulture Department maintains all existing landscapes both within and outside of the animal habitats throughout the Zoo. The Browse Program utilizes these landscapes as well as browse collected off-site and the program is based within the Animal Nutrition Department. These three departments (Planning and Design, Horticulture, and Animal Nutrition) all communicate with the Animal Health Department to gain approval to add new plants to the Browse List or to install landscape plants not yet reviewed for toxicity. While all four of these departments communicate with one another on daily needs, the rapid growth of the zoo and daily demands have offered little overlap in shared resources. In the few times a plant has been suspect in an Animal Health concern, the four departments have scrambled to collect relevant landscape history. This project was designed in part to help streamline the action response process in the event of a plant-based Animal Health concern.

Project Statement

The purpose of the project was threefold: First, to identify and consolidate historical planting information for every region of the zoo and document it in a single place. Second, to compare these findings to current plant selection and plant toxicity policies. And third, to outline a new policy governing plant specification and selection for internal use, but also for design consultant use.

Project Outcome

The final outcome of the project resulted in a working document that will be used as a resource for select members of the involved departments. The document is designed to be a common resource in the event of a plant related question or incident. It was decided that while this document should be easily accessible, the information should not be made public to all zoo employees, given the nuances of plant identification and plant toxicity, in addition to the variable influx of new scientific knowledge. Because of the fluctuating nature of scientific discoveries and the quasi-temporary nature of the zoological landscape, the document will stay in a “working” form to assimilate the ever-changing information that drives zoological and horticulture best practices. 

The document categorizes and lists past plantings by zoo region. In addition to the historical and current species lists, there is an approved browse list and a “Do Not Plant” list. The browse list is overseen and periodically updated by Animal Nutrition. The “Do Not Plant” list includes plants that are known to be toxic and/or invasive species in the State of Ohio. The list also notes species that are considered to be undesirable by the zoo’s standards due to their maintenance needs or performance issues. An example of an undesirable plant type is running bamboo. Its inclusion is based on its aggressive spreading habits which have caused maintenance issues in the past.

Further Insights

Interdepartmental discourse played a key role during the course of the project. The project generated discussion about implementing a biannual meeting between the departments to share new knowledge related to browse and plant toxicity. This meeting would serve to insure that the document would be revisited and updated. 

While reviewing the historical plant lists it was interesting but not surprising to find species such as Lonicera maackii (honeysuckle) and Berberis thunbergii (Barberry) included in plans drafted during the 1990s. This discovery generated further discussion about the role that invasive plants play in the zoo. It can be a challenging task to balance the zoo’s aesthetic, browse, and animal health needs in regards to horticulture. 

The tension between plant performance and ecological standards is well documented and presents a conundrum for zoo design and maintenance. When undesirable species play functional roles well, addressing this paradox is a complex task. For example, in the mid-west, the invasive plant such as bush honeysuckle (L. maackii) leafs out early and holds its leaves late into autumn, and grows well in shady conditions. Due to these characteristics, it performs as an optimal screening plant. While not intentionally planted in the past 20 years, local wildlife disperses its seeds, and we find honey suckle growing up under evergreen trees planted with the intention to hide views. Keeping these plants in check throughout the zoo’s buffer areas is not always easy due to the size of the grounds and the availability of resources and staff. While the removal of these plants is a priority (due to their invasive status), many times they play critical roles in screening both undesirable views and back of house areas (adding to the experiential nature of the zoo), as well as acting as a buffer between animal habitats contributing to the animals health through sense of safety and privacy. Eradicating honey suckle often means an equally strong performing screening plant must be purchased to continue to screen unwanted views.

Another example of this issue is the presence of thistle in the lion habitat. Part of the habitat is defined by steep earthen slopes which are eroding due to original plant failure. Thistle has established itself on the slopes and its root systems are now acting as slope stabilizers. This mitigates erosion and also prevents the zoo from having to replace the slopes with an expensive and undesirable concrete wall. Management plans are in place to prevent the thistle from spreading, but full-on removal would compromise the slope’s integrity.  An untraditional management plan is being discussed to manage thistle (do not permit to go to flower) until other more desirable plants can be established and the thistle removed.

These issues, while not the focus of the project, are brought forward to illustrate the complexity of horticulture within the zoo, as well as the importance of communication between departments in an effort to work more collaboratively.


We are very grateful to the AZH for funding this project. The document that was produced will greatly benefit multiple departments at the Columbus Zoo and Aquarium. The working document, when deployed in conjunction with other sources and staff expertise, will serve to further improve interdepartmental connection - something we believe to be a priority and an asset. Overall the project created healthy discussions centered around practical horticulture and design policy. More specifically, the project illuminated the benefit of cross departmental dialogue in respect to horticultural practice. 

If you have any questions related to the project, we welcome you to reach out to us. It is our hope that the collaborative nature of this undertaking will extend to other zoos as well. 

Stoyan Iordanov - Horticulture Manager

Karen Schenk - Director of Project and Site Design, Landscape Architect -Karen.Schenk@columbuszoo.org

Jonathan Stechschulte - Project Intern

Powered by Wild Apricot Membership Software