Winter is a good season to plan for spring. In today’s post, we want to tell you a bit about a type of planting that one can consider. This planting will boost the stability of our green spaces, turning them into havens of biodiversity. Let’s talk about floral supplementation and floral supplements.
What are floral supplements?
Floral supplements are semi-natural habitats that are added to green spaces and are designed to concentrate a large amount of plant resources into a small area. By including a mixture of herbaceous or woody flowering plant species, floral supplements provide food and habitat to local wildlife. This increase in floral resources correlates to local increases in the number of insect and other animal species and their abundance, which results in the improvement of ecosystem services in the area. Common examples include pollination, pest suppression, nutrient (re)cycling, soil conservation, and improvements in water provision and quality.
While supplements formed of mainly herbaceous flowering plants offer great nectar, pollen, and nesting resources to insects that act as pollinators and pest control agents, other plants can also be used to create floral supplements. In particular, woody plants and shrubs can provide valuable food and cover for various songbirds and small mammals. The benefits of floral supplementation go beyond supporting insects, birds, and mammals. In fact, these plant additions also have been shown to assist with weed suppression and to reduce soil erosion, while permanent woody plantings (e.g., hedgerows) can also serve as windbreaks.
Nowadays, floral supplements can be found nearly everywhere, from home gardens to roadsides, and croplands to city greenspaces, and are commonly referred to as “pollinator strips” or “conservation strips”. Generally, floral supplements are primarily implemented as a conservation initiative to support wildlife and arthropod biodiversity, particularly in floristically impoverished areas such as agricultural monocultures and urban environments.
The origin of floral supplementation
The concept of floral supplementation has roots in agriculture. For example, the use of companion plantings and flowering margins in and around crops has been long known to enhance biological control by boosting natural enemies of crop pests, such as predatory bugs and beetles, and parasitic wasps. In this respect, the addition of these plants to the agroecosystem has been recognized as a strategy to improve pest control with lower pesticide inputs.
Today, the concept has expanded in conjunction with aesthetic and conservation initiatives. For example, the Beautification Act of 1965 encouraged roadside wildflower plantings, and actions such as establishing pollinator gardens and defining no-mow months increase floral resources for pollinators. The USDA also offers conservation programs for monarchs and other pollinators by encouraging farmers and ranchers to plant pollinator-friendly wildflowers, shrubs, and trees (https://www.nrcs.usda.gov/).
How to start with floral supplements?
Although there is not a hard definition for what constitutes a floral supplement, guidelines have been proposed by government and conservation societies including the Xerces Society and the USDA. What species to plant ultimately depends on the location and purpose of the supplement. For example, recommended species to plant for upland or grassland habitats will be different than those for wetter habitats. Generally, however, regionally native or naturalized species are often recommended to sustain more native animal diversity than exotic species. In fact, because most ornamental plants used for aesthetic purposes are often non-native, they tend to offer unsuitable or no resources to the local animal communities. Further, even among native species, regional varieties (i.e., local ecotypes) are often preferred because they are better adapted to the local climates, growing conditions, and living communities.
Another aspect to consider when starting or creating floral supplements is the diversity of plants used. In fact, diversity is a common theme for floral supplements: one seeks to obtain a high diversity in flower color, flower shape, and bloom times. For example, the best supplements contain a mixture of annuals, perennials, and woody plants that bloom at different times throughout the growing season to ensure that floral resources will be sustained over time. Further, including flowers with diverse shapes, colors, and sizes facilitates access to nectar and pollen for arthropods with different mouth and body shapes.
Although one can try to do it by oneself, designing a floral supplement can be tedious and sometimes overwhelming. Luckily, federal agencies, seed companies, and local nurseries have mixes available for certain habitat types and regions, that one can order directly.
To learn more visit:
USDA, Natural Resources Conservation Service
Xerces Society in the Northeast
Site preparation guidelines for pollinator gardens (PDF)
By Katy Ciola Evans, Ph.D. student in the Espíndola Lab, University of Maryland Department of Entomology. View her website to learn more about her research.
