Corson Pollinator and Rain Garden

Icon with meadow and tree

Corson Pollinator and Rain Garden

Corson Hall Pollinator and Rain Garden

Sustainable Landscapes Trail at Cornell University

The Corson Hall pollinator and rain garden is an ecologically focused landscape that intersects several campus sustainability goals. The site is designed as a low maintenance planting of woody and herbaceous materials selected to enhance pollinator habitat as a replacement for a residual lawn space. The design captures rainwater to promote good growing conditions while filtering stormwater and reducing harmful effects of stormwater runoff. The students of ‘Creating the Urban Eden’ (PLHRT/ LA 4910-4920), developed a planting design and plant list for this space, and installed the plants. This landscape was funded by the Student Assembly Infrastructure Fund.

Why is this site sustainable?

Reduces sidewalk and plaza storm water direct runoff into storm drains that empty into Cayuga Lake;
Allows precipitation and runoff to infiltrate into the rain garden, filtering polluted runoff through the soil;
Supports diverse vegetation that uses precipitation and runoff;
Provides food and habitat for pollinators and insects;
Is used as a teaching landscape to learn about plants appropriate for these uses.

Pollinator and Rain Garden Design and Construction

Site Analysis:

The class performed a site analysis including sampling soil pH, bulk density, and infiltration rates.

Soil texture was classified as predominantly loamy sand within the top 12”.
The soil pH was uniformly alkaline (pH 7.6 to 8.2) typical of much of the Cornell campus.
Bulk densitywas highest on the shoulders of the proposed rain garden basin and to the south of site.
Infiltrationwas rapid within the basin.
This is a full sun site with windows on the east face of Corson that must not be blocked

Design:

Each student designed a landscape planting plan for a functional rain garden to support pollinators on the Cornell campus.

Rain Gardens: The rain garden is fed by storm water runoff from the sidewalk and plaza directed into a low area. The garden is a ‘bowl’ with high drier areas and low areas that are more apt to experience temporary saturated conditions after a rain. The class explored issues related to construction of a rain garden and selection of plants for this environment.

Pollinator Habitats: The class explored issues related to pollinator habitat, and design of landscapes to support native specialist bees in particular. Plants were selected to provide a diversity of flower types and pollen throughout the growing season.

Construction:

Soil on site was remediated using the ‘Scoop and Dump’ technique where 6 inches of compost was spread over the site and deeply incorporated to 18 inches using a backhoe. Most plants were container grown making them convenient for students to plant. Stone cobbles were used where concentrated runoff enters the rain garden to slow the water and minimize erosion. A small seating area with native stone benches was included to provide a gathering and observation area in the garden.

Plant Selection:

Plants able to tolerate variably wet and drought conditions and that support native pollinators were used on this project site. While not all the plant species are native to the Finger Lakes region, no invasive species were used in this garden. The partial plant list below gives the common name followed by the scientific name (italicized) and specific cultivar (in ‘single quotes’). The landscape was installed in May 2021.

Trees:

Redbud Cercis canadensis ‘Forest Pansy’

Sweet Gum Liquidambar styraciflua ‘Slender Silhouette’

Shrubs:

Bluebeard Caryopteris x clandonensis ‘Dark Knight’

Buttonbush Cephalanthus occidentalis ‘Sugar Shack’

Climbing Hydrangea (vine) Schizophragma ‘Rose Sensation’

Diervilla Diervilla rivularis ‘Kodiak Orange’

Dogwood Cornus stolonifera ‘Arctic Fire’

Juniper Juniperus chinensus ‘Montana Moss’

Ninebark Physocarpus opulifilius ‘Amber Hubilee’, ‘Summer Wine’,

‘Ginger Wine’, Festivus Gold’`