I want to inspire you to support nature and Surrey’s conservation groups and make a positive difference for the Small Blue Butterfly by growing Kidney Vetch (Anthyllis vulneraria) in your garden, or at your school, workplace, or allotment.

The Small Blue Butterfly is Britain’s smallest butterfly; it was once common in Surrey.  This rarity is classified with Near Threatened status by the IUCN Red List.  The Small Blue is very vulnerable to habitat loss, as caterpillars only feed on one food plant, Kidney Vetch.  Kidney Vetch is a short-lived plant that declines among robust grasses and requires areas of bare ground to enable the plants to successfully self-seed and maintain populations.  Small Blue caterpillars face further threats from rabbits grazing.  Small Blues are often isolated, as they’re restricted and can only survive in areas where Kidney Vetch grows.

Butterfly Conservation’s Surrey Small Blue Stepping Stones Project ran from 2017 until 2019, creating habitat ‘stepping stones’ for Small Blue Butterflies across the North Downs by creating areas of bare ground and sowing these with Kidney Vetch.  This gives Small Blue Butterflies the opportunity to increase their range; allowing greater numbers of butterflies to meet and move between sites.  Several organisations worked together to achieve a successful outcome for the project, including the Surrey Branch of Butterfly Conservation, The Surrey Wildlife Trust, National Trust, Pewley Down Conservation Volunteers, and Guildford Borough Council.

The Small Blue can now be found on more sites: along the North Downs from Guildford to Dorking, Epsom, Ewell, Banstead, Chipstead, and also in East Surrey.  Kidney Vetch grows at Howell Hill, Hutchinson’s Bank, Pewley Down, Hatchlands Park, Hackhurst, Newlands Corner, Norbury Park, The Mount, Polesden Lacey, Runfold Ridge, Epsom Golf course, and Priest Hill.  The Butterfly Conservation Surrey Branch Conservation Group has recently established Kidney Vetch at sites between Farnham and Guildford and hope Small Blue Butterflies will colonise along the Hog’s Back.

Improved habitat for the Small Blue is produced by creating areas of bare ground, digging scrapes, or identifying areas where chalk is close to the surface.  Low fertility soil prevents dominant plants from establishing and gives Kidney Vetch the greatest chance of persisting.  The Epsom Downs provide the ideal growing conditions.

The Surrey Butterfly Conservation Group are looking for new opportunities to sow Kidney Vetch seeds.  Bill Downey is keen to develop new plantings of Kidney Vetch where there are gaps in the habitat.  By linking these areas, we can give the Small Blue Butterfly greater resilience, by increasing the number of butterflies, but also protecting the species by expanding their genetic diversity.

Small Blue Butterflies are on the wing from late May until the end of June.  Smaller numbers of Small Blues can be observed when a second brood of butterflies emerges in August.  Female Small Blue Butterflies lay their eggs amongst Kidney Vetch (Anthyllis vulneraria) flowers.  The larvae initially live within the calyx of the flower, feeding on blooms and developing seeds before dispersing into the sward.

Together we can help the Small Blue Butterfly by growing Kidney Vetch (Anthyllis vulneraria) in our gardens.  Kidney Vetch makes a superb container plant for a sunny patio.

If you care about our butterflies, bees, moths, hoverflies, and other insects, please never use any insecticides, pesticides, or herbicides in your garden or allotment.

For more information about growing Kidney Vetch, please click here.

For gardening advice for March, please click here.

To see more articles about gardening for butterflies, please click here.

To read more articles about growing caterpillar food plants, please click here.

To see more articles about growing plants for pollinators, please click here.

To see my guide to creating a meadow, please click here.