Plant Hardiness Zones around the World


Plant hardiness defines the lowest temperature at which a plant will survive during the winter.

The zones are defined differently in the UK, the US and Europe.

The UK uses the Royal Horticultural Society (RHS) Zones:

  • H – Fully Hardy – Hardy to -15 degrees C (5 degrees F)
  • FH – Frost Hardy – Hardy to -5 degrees C (23 degrees F)
  • HH – Half Hardy – Hardy to zero degrees C (32 degrees F)
  • FT – Frost Tender – Not hardy below 5 degrees C (41 degrees F)

The rest of Europe uses the European Garden Flora (EGF) Zones:

  • H1 – Hardy to -20 degrees C (-4 degrees F) and below
  • H2 – Hardy to -15 to-20 degrees C (5 to -4 degrees F)
  • H3 – Hardy to -10 to -15 degrees C (14 to 5 degrees F)
  • H4 – Hardy to -5 to -10 degrees C (23 to 14 degrees F)
  • H5 – Hardy to zero to 5 degrees C (32 to 40 degrees F)
  • G1 – Requires cool greenhouse protection
  • G2 – Requires heated greenhouse protection

The US uses a wider zoning system which is detailed in the diagram below:

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