Level II Accreditation

Arboreta with larger collections and more extensive outreach can take a step up in accreditation.

Level II accreditation is awarded to arboreta with at least 100 labeled species or taxa of trees and other woody plants in their collections, and a clear commitment to public education and collections management.

This accreditation recognizes institutions with growing capacity and outreach programs, as well as signage or interpretation. It is a notable achievement for tree-focused organizations.

To qualify at Level II, an arboretum must demonstrate more advanced planning with more detailed documentation, and show that it has a structured approach to plant curation and public engagement.

Many different types of organizations have earned Level II arboretum accreditation.

How to Become Accredited

To become accredited, submit documentation showing your organization meets the Level II criteria below, along with your online application.

Level II Criteria

An arboretum plan
A governing group
Paid management
A labeled collection of 100 or more taxa (species, subspecies, cultivars, varieties, etc.) of trees and other woody plants
A collections policy
At least one tree-related event a year that is open to the general public
Expanded educational and public programming

Download a sample Level II application.

Compare all levels of accreditation.

Find more resources to help with the accreditation process.

Apply Online

When you’re ready, submit your application online. There is no fee to apply.

Once your completed application is submitted, ArbNet staff will review your materials. Decisions are typically made within four weeks.

ArbNet accreditation is free and valid for 5 years. Arboreta can upgrade their accreditation at any time when higher-level requirements are met.

Level II Criteria

The following criteria must be met and supported by documentation to achieve Level II accreditation.

An arboretum plan
A governing group
Paid management
A labeled collection of 100 or more taxa (species, subspecies, cultivars, varieties, etc.) of trees and other woody plants
A collections policy
At least one tree-related event a year that is open to the general public
Expanded educational and public programming

Download a sample Level II application.

Level II Criteria

An Arboretum Plan

You must have an overall plan for the space you intend to care for. This can be a business plan, organizational plan, a strategic plan, a master plan, or another—any documentation that defines the purpose of your arboretum and your plan to continue caring for the plants within your arboretum can be accepted as an arboretum plan.

An arboretum plan must define:

The purpose and mission of the arboretum
Its audiences
The types of plants that are grown to achieve the arboretum’s purpose or serve its audiences
Provisions for the maintenance and care of the plants
Provisions for the continuing operation of the organization through time with a clear succession plan

Depending on your organization or institution, your arboretum plan will more likely come from the organization and you should then develop a mission statement as it specifically relates to being an arboretum.

Download an example of an arboretum plan.

A Governing Group

To be accredited, your arboretum needs a dedicated group of people that is committed to the care of your arboretum, following the arboretum plan, and ensuring the future of the arboretum and that the plan can be carried out beyond a single individual. This group is known as a governing group.

This governing group will affirm fulfillment of accreditation standards and authorize the organization’s participation with ArbNet as an accredited arboretum.

Examples of governing groups include committees, boards, and oversight groups.

Governance groups do not have to be solely dedicated to the arboretum specifically, but can manage the arboretum along with other broader organizational responsibilities.

Paid Management

One or more arboretum employees who have job responsibilities that specifically include management or operation of the arboretum.

Have a Labeled Collection of 100 Kinds of Woody Plants

The core of an accredited arboretum is its collection of woody plants and trees.

For Level II accreditation, an arboretum must have a collection of 100 or more different taxa (species, subspecies, cultivars, varieties, etc.) of trees or other woody plants that are labeled or mapped in some way that’s accessible or visible to the public.

Labeling and maps can be physical or digital. There are many different free labeling solutions available. Learn more about Labeling and Maps solutions to meet accreditation criteria.

All trees do not need to be labeled; just a selection of at least 100 species or taxa for easy public awareness.

A Collections Policy

A collections policy describes the development and professional management of the plants in the arboretum collection in accordance with standards developed in the public garden and museum fields with consideration given to the Saint Louis Declaration regarding invasive species.

Such a policy and related practices includes a rationale for holding the particular collections of the arboretum, and collections inventory and record-keeping practices.

See the list of example collections activities.

Host Enhanced Educational Events and Public Programming

Enhanced educational and public programming beyond the base level required in Level I accreditation. Programs must be related to trees (e.g. tree identification, ecology, conservation, collections, or some other tree-focused aspect of the arboretum mission or master plan. See checklist below.

Resources

Download a sample Level II application.

Explore different kinds of Level II accredited arboreta around the world.

View and download a summary of the accreditation for all levels I—IV.

Use ArbNet’s Arboretum Tool Kits to find specific advice on applying as:

A cemetery arboretum
A city arboretum
A school arboretum
A university arboretum

More accreditation resources are available to assist with the application process.

Examples of Collections Activities

A collections policy is required for Level II accreditation through ArbNet, but participation in additional collections activities beyond that are optional.

This list is meant to provide inspiration and ideas for arboreta wishing to expand and advance their collections management.

A collections policy (covers records management, accessioning, deaccessioning, etc.)
Regular collections evaluation
Conducting or participating in woody plant evaluation trials
A staffed collections manager or curator
An herbarium
A seed bank
A plant exploration program
Collections conservation (holding and safeguarding plants of collections or conservation value on behalf of the collective interests of the profession, e.g., rare and endangered plants, legacy cultivars, etc.)
A woody plant nursery
A woody plant breeding program
Any accredited or officially recognized collection(s)
A collections strategic plan (develops and plans for the themes and direction of your collections—could be a standalone plan or part of your greater organization-wide strategic plan or expanded collections policy)

Education and Community Engagement Activities

The following lists include common types of activities, in generally increasing levels of scale and complexity, that arboreta can host to meet accreditation requirements or to use as inspiration to expand event and outreach initiatives to meet higher levels of accreditation.

On the digital ArbNet accreditation application, you will be asked to check all activities your arboretum participates in.

Open Public Access and Events

Annual tree events (Arbor Day, International Forestry Day/week)
Self-guided walking tours
Giving engagement and outreach presentations for other organizations and groups
Hosting conferences or similar events
Exhibitions and/or interpretive signage

Recurring Public Programming

Guided walking tours or tram tours
Docent training and opportunities
Conference (or similar venue) presentations
Course/class/workshop offerings
Hosting webinars/ seminars
Community/citizen science programs
Children’s garden
School programs

Extensive / Enhanced Educational Programming

Articulated engagement philosophy or interpretive plan with intended outcomes and assessment plan
Plant selection, care, and/or pest/disease consultation and support
Educational and outreach publications
Digital content—podcasts, online courses, social media outreach, etc
Ethnobotanical engagement (Indigenous knowledge content and co-creation with community partners)
Accredited educational or training programs
Internship opportunities
Summer/ seasonal camps

Urban and Community Forestry