Providing flowers throughout the season can be essential to attracting pollinators, no matter what landscape is near your garden.

A diverse and abundant flower garden that provides blooming flowers all season may be more important to bees and other pollinators than anything surrounding the flower garden, according to a study published September 4, 2024 in PLoS ONE by Devon Eldridge of the University of Tennessee, USA, and colleagues.

As we learn more about the importance of pollinators (bees, butterflies, and other native and non-native insects) to our food supply and ecosystem, many people are planting pollinator-attracting flower gardens to help support the survival of these important and endangered creatures. Eldridge and co-authors investigated whether and how the context of these gardens (e.g., the surrounding local context and broader land-use factors) might impact the attractiveness of flower gardens to different bee species.

The authors worked with four types of gardens: three planted only with plants from a single family – Asteraceae (daisies), Fabaceae (legumes) or Lamiaceae (mints) – and one garden composed of a mixture of plants from all three families.

They replicated the four garden types at five different sites representing a variety of surrounding land uses: urban garden, forage meadow, mixed farming, forest, and organic farm. From 13 July to 17 August 2020, they then sampled bee species in the garden plots and also conducted local surveys within a 50 m radius of each garden on a weekly basis.

The authors collected 1,186 bees of 44 different species during a 20.83-hour sampling period in the garden plots. When surveying the local areas surrounding the trial garden plots, the authors collected 2,917 bees representing 52 different species over a total of 16.67 hours. The mixed-farm garden site had the highest abundance of bees among the specific garden surveys, while the area surrounding the urban garden site had the highest abundance among the surrounding local surveys.

The floral composition of individual plants (the number of flowers available on a plant) and the diversity of flowers in the wider local area had no effect on bee abundance or species richness in garden plots. Although there was a positive association between developed land use within a 2 km radius and bee abundance in gardens, the effect was small. The main determinants of bee community composition and species richness in gardens were the size of the floral arrangement and variation in flowering garden plant species.

The authors note that all of their gardens were located in “patchy” and heterogeneous landscapes, and that gardens surrounded by habitats with more extreme and/or different land uses might yield different results. Nevertheless, these results suggest that landowners have the power to promote local pollinator communities by conserving existing natural patches and/or planting more flowers, particularly groups of flowers to ensure flowering throughout the season, regardless of the environment their garden is located near.

The authors add: “We often wonder how the area surrounding our gardens affects the pollinators that visit our flowers. In our study, we found that the number and types of flowers in the garden itself mattered more to pollinator abundance and diversity than the surrounding local or landscape context.”