Evaluating flowering plant selection for pollinator habitat enhancement: Open-pollinated natives vs. native cultivars

Evaluating flowering plant selection for pollinator habitat enhancement: Open-pollinated natives vs. native cultivars

Summary

This research seeks to improve flowering plant selection for pollinator habitat enhancement by comparing “true” native plants (open-pollinated) to native cultivars (human-bred) in terms of their ability to attract and support native pollinators.

A controlled field study is underway to determine if cultivars of native flowering plants are as attractive to beneficial pollinators and provide the same nectar resources as true native species. Two field plots and two educational gardens were designed, installed, monitored and maintained during the 2012 growing season at the farms of our three farm partners. Preliminary observations were made on pollinator diversity and abundance in and around the study plots. Data collection on the frequency and duration of pollinator flower visits and nectar production will begin in spring 2013.

Opportunities for learning about beneficial pollinators and pollinator habitat were provided to horticulturalists, agriculturalists, and home gardeners through educational signage at all four established gardens. An educational tour of the pollinator habitat garden at Full Circle Gardens in Essex, VT was given to members of the Vermont Nursery and Landscape Association at the August 2012 summer twilight meeting. Additional tours, speaking engagements, and signage will be pursued in 2013.

Objectives/Performance Targets

The primary objective of this research is to improve flowering plant selection for pollinator habitat enhancement by comparing “true” native plants (open-pollinated) to native cultivars (human-bred) in terms of their ability to attract and support native pollinators. This research project also aims to disseminate information to horticulturalists, agriculturalists, and home gardeners about the importance of native pollinator habitat and methods for establishing and/or restoring habitat to support beneficial native pollinator populations.

To accomplish the primary objective of this research, a controlled field study is underway to determine the abundance and diversity of native pollinators visiting and extracting nectar from open-pollinated native flowers versus native cultivars within pollinator habitat gardens in agricultural landscapes of Vermont. Two field plots and two educational gardens were designed, installed, and maintained during the 2012 growing season at three farm partner sites. Preliminary surveys of pollinator species were conducted and methods for data collection were tested in preparation for true data collection in 2013.

Learning opportunities for horticulturalists, agriculturalists, and home gardeners were provided through educational signage at all the established gardens and through a tour of the pollinator garden at Full Circle Gardens through the Vermont Nursery and Landscape Association summer twilight meeting. Additional public speaking engagements, signage, and populating a website are planned for 2013.

Accomplishments/Milestones

Site Selection/ Farm Partners: A location for a data collection pollinator garden was identified at River Berry Farm in Fairfax. We were unable to fit a full data collection pollinator garden at Full Circle Gardens in Essex due to increased need for space at the nursery. A smaller, educational pollinator garden was established at Full Circle Gardens and to compensate, the sizes of the two data collection gardens were increased at the other sites. With the large garden size, we were unable to secure a garden site on the UVM campus. Instead, we established a third farm partnership with Maidstone Plant Farm in Maidstone, VT. Both a large data collection pollinator garden and an educational pollinator garden were established at Maidstone Plant Farm.

Plant Selection and Acquisition: A selection of native herbaceous flowers and cultivars of the same species were chosen following in-depth research about each plant’s form, habits, and availability. An effort was made to choose flowers that bloomed at different times throughout the season and varied in size, color and flower structure.

Most of the plants were only available from wholesale nursery as small plugs rather than the preferred quart-size pots. When the plugs arrived, they were transplanted into an organic potting soil from Vermont Compost in quart-size pots and grown out for the summer at Maidstone Plant Farm. The two large data collection pollinator gardens were prepped over the summer and the flowers were planted in late summer/early fall 2012 at River Berry Farm and Maidstone Plant Farm.

Garden Planting/Size: The two data collection pollinator gardens are 3000 sf with 15 native herbaceous flowering perennial genera represented—one open-pollinated and one cultivar. Six plants of each plant type are grouped in a randomized complete block experimental design with three replicates at each site. A combined total of 1224 plants are planted for data collection, which is more than the 810 plants in the original grant proposal. The larger sample size will strengthen the significance of the results.

Educational Outreach: Educational signage was designed and installed at the educational pollinator gardens at Maidstone Plant Farm and Full Circle Gardens. The signage explains the importance of native pollinators, the purpose of this research project, and offers instructions to home gardeners on how to create pollinator habitat in their own gardens. A tour of the pollinator garden at Full Circle Gardens was provided through the Vermont Nursery and Landscape Association summer twilight meeting.

Data Collection Preparation: Preliminary observations were made on pollinator diversity and abundance in and around the study plots throughout the summer of 2012. Data collection on the frequency and duration of pollinator flower visits and nectar production will begin in spring 2013.

Impacts and Contributions/Outcomes

Even in the early stages of this research project, the target audiences (farmers, horticulturalists, and home gardeners) are being engaged and educated about the importance of native pollinators, the differences between open-pollinated native flowers and native cultivars, and how to enhance pollinator habitat in both agricultural landscapes and home gardens. We have impacted these audiences through our educational signage at the pollinator gardens and through speaking engagements. As a result of the public interest and curiosity about pollinator habitat, Riverberry Farm began identifying perennials for sale in their nursery that are pollinator-friendly. Educational opportunities and engagements will greatly increase in 2013, as the gardens are more established and data collection is underway.

Collaborators: