Gardenstar tool

Location: Aotearoa New Zealand
Project type: Public-facing assessment and engagement tool
Delivery/lead organisations: People + Cities + Nature
Date/period: 2020s – ongoing
Scale: Site (private garden)
Primary system or theme: Urban biodiversity, private green space

Context

Why this site matters
Gardenstar is a New Zealand-specific urban garden biodiversity self-assessment tool. Private gardens make up a substantial proportion of urban land in Aotearoa New Zealand and influence biodiversity outcomes that sit outside formal planning controls.1 Gardenstar was developed to engage householders in recognising and improving the biodiversity value of these private spaces.1

Challenge or constraint

What wasn’t working/what needed to change
Public-facing discussion of backyard biodiversity has highlighted a gap between household interest and access to practical, user-friendly assessment and improvement guidance.2 At the same time, New Zealand research-led residential biodiversity tools are designed for repeatable scoring and application by practitioners or institutions, making them less directly accessible for household self-use.3,4

Intervention

What was done
Gardenstar was developed as an online, qualitative self-assessment tool that enables householders to evaluate and improve biodiversity-supporting features in private gardens.1

Key components

  • Structured self-assessment covering planting, habitat features, water, and management practices1
  • Qualitative scoring system with explanatory prompts
  • Tailored guidance encouraging native planting and habitat provision
  • Public accessibility with low technical or data requirements

Implementation notes

Design and delivery considerations

  • The tool is intended for education and engagement rather than accreditation or regulatory use
  • Relies on self-reported information rather than independent verification
  • Designed for individual garden parcels, not neighbourhood or catchment assessment
  • Outcomes depend on user motivation, interpretation, and follow-through

Outcomes

Observed or reported outcomes

  • Increased user awareness of biodiversity-supporting garden features and practices1,2
  • Uptake as a public-facing engagement tool in urban residential contexts

What is plausible but unmeasured

  • Incremental increases in native planting and habitat features across participating gardens
  • Cumulative contributions to urban biodiversity at the neighbourhood scale, if widely adopted

Evidence and limits

What the evidence supports
Evidence supports Gardenstar’s role as an educational and engagement tool that encourages pro-biodiversity behaviours in private gardens.1,2

Key limitations or uncertainties

  • No published quantitative monitoring of biodiversity outcomes attributable to tool use
  • Self-assessment limits comparability and repeatability across sites
  • Not suitable for regulatory, benchmarking, or performance-based assessment3,4
  • Garden-scale actions remain constrained by socio-economic context and broader urban pressures5,6

Relevance to design practice

  • Use Gardenstar as a complementary engagement tool where projects rely on private land stewardship
  • Avoid treating qualitative public tools as substitutes for quantitative biodiversity assessment frameworks
  • Pair household-scale engagement with neighbourhood- or development-scale tools where performance outcomes are required3,4
  • Recognise limits of garden-scale action where social inequities and biosecurity risks may dominate outcomes5,6

References

  1. People + Cities + Nature. (n.d.). Garden Star tool. peoplecitiesnature.co.nz
  2. Stuff. (2022, August 7). Measuring biodiversity – How would your backyard score? stuff.co.nz
  3. Van Heezik, Y., Barratt, B., Burns, B., Clarkson, B., Cutting, B., Ewans, R., Freeman, C., Meurk, C., Shanahan, D., Simcock, R., Souter-Brown, G., Stanley, M., Stanley, R., Thorsen, M., Wake, S., Woolley, C., Zink, R., & Seddon, P. (2023). A rapid assessment technique for evaluating biodiversity to support accreditation of residential properties. Landscape and Urban Planning. doi.org/10.1016/j.landurbplan.2023.104682
  4. Theis, J., Woolley, C., Seddon, P., Shanahan, D., Freeman, C., Pedersen Zari, M., & van Heezik, Y. (2025). The New Zealand Biodiversity Factor—Residential (NZBF-R): A tool to rapidly score the relative biodiversity value of urban residential developments. Land, 14(3), 526. doi.org/10.3390/land14030526
  5. Hand, K., Freeman, C., Seddon, P., Stein, A., & van Heezik, Y. (2016). A novel method for fine-scale biodiversity assessment and prediction across diverse urban landscapes reveals social deprivation-related inequalities in private, not public spaces. Landscape and Urban Planning, 151, 33–44. doi.org/10.1016/j.landurbplan.2016.03.002
  6. Hulme, P. E. (2020). Plant invasions in New Zealand: Global lessons in prevention, eradication and control. Biological Invasions, 22, 1539–1562. doi.org/10.1007/s10530-020-02224-6