The Morton Arboretum’s plant collections are recognized as one of the most significant collections of cold-hardy trees and shrubs worldwide. They are open to the public for study and exploration, and are frequently utilized for formal research projects and educational courses. This plan provides a strategic framework for collections development, with the goal of improving their diversity, maintenance, and visitor experience well into the Arboretum’s future.
In the original plan, completed in 2001, many ideas were embraced with significant progress made towards their fruition, whereas others were deemed unfeasible due to horticultural conditions, institutional priorities, or excessive cost. An effort was initiated in 2015 to document progress made to date and revisit goals based on current understandings of site conditions and institutional priorities.
Significant changes to the plan are summarized below:
- Development of a horticultural “West Side Entry” collection in place of an expanded Oleaceae collection due to Emerald Ash Borer.
- Scope expansion of Flowering Trees Collection to include genera such as Styrax and Koelreuteria to extend flowering time.
- Scope reduction in Magnoliidae collection to focus on Magnolia. Development of Magnolia collection to continue in east side, as opposed to west side.
- Betulaceae collection not to be expanded as described in Collections Master Plan
- Salicaceae collection not to be expanded, but existing “Willow Island” area remodeled to focus on superior performing taxa and cultivars recommended for planting in the Chicagoland Region
- Thuja collection to be retained on the west side.
- Plants of Europe Collection not to be split into biogeographic subregions requiring extensive site modification, instead to continue as is with a greater focus on eastern european flora and germplasm likely to thrive in our climate.
- Rosaceae collection to change in scope, focusing on species of economic importance or exhibiting superior performance.
- Scope change in Pinetum to become a horticultural collection focusing on botanical species and cultivars recommended for planting in the Midwest.
- Diversity collection to be dissolved, with this area instead used to exhibit trees and shrubs of conservation concern.
- Saxifragaceae collection to be dissolved instead of expanded.
- Establishment of a “List of Priority Genera”, consisting of the Arboretum’s six nationally accredited collections (Acer, Magnolia, Malus, Tilia, Quercus, Ulmus) and an genera of interest (Aesculus, Amelanchier, Carya, Crataegus, Fagus, Juglans)
The Morton Arboretum