The selection of appropriate locations for pollinator habitat is important to protect pollinators from inputs such as pesticides and to maximize habitat benefits. Pollinators need food (pollen & nectar), nesting and clean water sources, so these are important components for site selection. As a general rule, the habitats most beneficial to local pollinators will be those that historically existed in that general area. This may mean treeless prairie habitat in some areas and tree and shrub planting in others. Below are some considerations for site selection, followed by habitat assessment guides for rural and urban landscapes to further guide decision-making about pollinator habitat locations or to assess the quality of pollinator habitat before and after projects are completed. BWSR also has assessment forms for solar projects as part of the Habitat Friendly Solar Program, this information is found the program's webpage. The following are key considerations for selecting pollinator habitat projects:
Site Assessment Forms
BWSR has developed assessment forms for rural and urban landscapes. The following are links to the assessment forms followed by guidance for the use of each assessment.
Rural and Urban Landscapes Assessment Form Guidance
The following summary provides information about the concepts and ideas behind each question in the habitat assessment forms for rural and urban landscapes. These assessments are intended to be used to determine if proposed project plans will likely lead to successful habitat or to assess projects after they are established.
Size of Project Providing Pollinator Habitat
Pollinator habitats must have room to provide adequate foraging and nesting spaces for pollinators.
Rural landscapes should have at least 0.5 acres of pollinator habitat, with a goal of at least 1.0 acre. Larger areas will likely provide greater flower and nesting opportunities.
Urban landscapes are often more limited in available space. While all sizes of pollinator habitats are beneficial in some way, there should be room for clusters of plants instead of single plants, room for nesting such as bare ground for ground nesting pollinators or logs/lumber with holes for cavity nesting bees, and a shallow clean water source.
All types of habitats listed in the assessment form are beneficial to pollinators; however, the habitat type will determine what types of plants will be suitable for the project. If benefiting a particular type of pollinator or specific species of pollinator is a project goal, it is important to determine what types of habitat and plants that pollinator uses. As a general rule, the habitats most beneficial to local pollinators will be those that historically existed in that general area.
Pollinators prefer variety when searching for nectar or pollen. Bees, butterflies, moths, and birds are all drawn to different types, shapes, and colors of flowers. They use different plants for nesting and larval feeding. Planting a wide variety of plants helps ensure value for a wide range of pollinators that may visit the habitat.
Invasive plants reduce diversity and are generally visited by native pollinators less often, so are not counted towards species totals.
Seasons with Three Blooming Species Present
It is important that pollinators are able to find nectar from early spring through late fall. Pollinators are more likely to use a habitat that they can rely on throughout the growing season. See the plant selection part of this pollinator toolbox for the bloom seasons of different plant species.
Many species of pollinators utilize different habitats for foraging and nesting. Being connected to another habitat increases their chances of survival. These connections are referred to as corridors.
Some species of pollinators can only travel very short distances at a time, sometimes less than a couple hundred feet. Sufficiently wide corridors play an important role in movement and migration of pollinators, especially smaller species. They help increase genetic diversity by connecting populations and support the re-establishment of populations of pollinators that have been reduced through habitat loss from development, disease, or events such as fire or flooding.
Available Habitat Components
Nesting and clean water sources are vital for pollinator health and development and include lakes, streams, rivers, ponds, and wetlands. Xerces Society provides information on different types of nesting sites that can be added and how to keep them maintained. Water can also be provided in residential landscapes through shallow containers with sloping sides that are kept clean by changing with fresh water (not through the use of chemicals or soaps). Adding rocks or gravel that rise above the water surface provide resting sites and reduce the risk of drowning.
Pesticides used to control insects can drift into pollinator habitats during application, or move into the habitat through water sources. If surrounded by areas that use pesticides, pollinators are more at risk by moving through those areas to reach the habitat. Habitat locations should be a minimum of thirty feet from areas treated with pesticides.
Agricultural areas are not the only pesticide risk. Chemically treated lawns and gardens using pesticides or insecticides, especially those containing harmful neonicotinoids, should also be considered. Trees and tall vegetation can provide buffers from pesticide drift or run-off.
Likelihood of Meeting Pollinator Species Goals
Assess the likelihood of habitat to meet specific pollinator species goals. Consider if the habitat will provide the species specific nectar sources, pollen sources, larval food sources, nesting needs, and minimization of risks.
Expected Project Lifespan
Pollinators require reliable habitats. The investment of time and resources into creating the habitat will have the greatest return the longer it can be maintained. Some plants require two to three years to establish and all projects need long-term care to maintain pollinator benefits.
Look for areas where the habitat score can be improved. Changing the location or configuration of habitat might increase scores related to available acreage, habitat connections, and pesticide risk. Adding additional plant species can increase values for diversity, seasons with blooming species present, and likelihood of meeting pollinator species goals. Low and medium quality habitats should look at ways to raise the quality of the habitat to a high or exceptional level.