Rose Climate & Hardiness Zones

Compare global hardiness systems, pick the scale you use locally, and browse rose varieties matched to your winter climate.

Show zones using

USDA zones 1–13

Each zone is defined by the 30-year average annual extreme minimum temperature. Select a zone to see recommended rose classes and roses in our encyclopedia rated for that zone.

1 USDA Zone 1 < -45.6°C 2 USDA Zone 2 -45.6 to -40.0°C 3 USDA Zone 3 -40.0 to -34.4°C 4 USDA Zone 4 -34.4 to -28.9°C 5 USDA Zone 5 -28.9 to -23.3°C 6 USDA Zone 6 -23.3 to -17.8°C 7 USDA Zone 7 -17.8 to -12.2°C 8 USDA Zone 8 -12.2 to -6.7°C 9 USDA Zone 9 -6.7 to -1.1°C 10 USDA Zone 10 -1.1 to +4.4°C 11 USDA Zone 11 +4.4 to +10.0°C 12 USDA Zone 12 +10.0 to +15.6°C 13 USDA Zone 13 > +15.6°C

USDA, RHS, EGHZ & NRCan cross-reference

Compare how each USDA zone maps to RHS, European garden, and Canadian hardiness ratings. Select a USDA zone to open its detail page.

USDA Min. temp. (°C) Min. temp. (°F) RHS EGHZ NRCan Climate class
USDA Zone 1 < -45.6 < -50 — 0 0 Arctic Alpine
USDA Zone 2 -45.6 to -40.0 -50 to -40 H7 2 1 Subarctic
USDA Zone 3 -40.0 to -34.4 -40 to -30 H7 3 2 Northern Taiga
USDA Zone 4 -34.4 to -28.9 -30 to -20 H7 4 3 Middle Taiga
USDA Zone 5 -28.9 to -23.3 -20 to -10 H6 5 4 Southern Taiga
USDA Zone 6 -23.3 to -17.8 -10 to 0 H5/H6 6 5 Mixed Forest
USDA Zone 7 -17.8 to -12.2 0 to 10 H4/H5 7 6 Forest-Steppe
USDA Zone 8 -12.2 to -6.7 10 to 20 H4 8 7 Steppe
USDA Zone 9 -6.7 to -1.1 20 to 30 H3 9 8 Semiarid
USDA Zone 10 -1.1 to +4.4 30 to 40 H2 10 9 Subtropical
USDA Zone 11 +4.4 to +10.0 40 to 50 H1c 11 — Moist Tropical
USDA Zone 12 +10.0 to +15.6 50 to 60 H1b — — Humid Equatorial
USDA Zone 13 > +15.6 > 60 H1a — — Hyper-Humid Equatorial

Hardiness maps

The European Garden Hardiness Zones (EGHZ) adapt the USDA framework to continental climates — mild maritime zones in the west and harsher continental bands across Eastern Europe and Ukraine.

USDA map with English labels
USDA zones across Europe.

Global hardiness systems

USDA

International baseline based on extreme minimum temperature (zones 1–13).

RHS

UK/European ratings (H1a–H7) with glasshouse vs outdoor context.

EGHZ

European garden zones aligned with USDA minimum temperatures.

NRCan

Canadian Plant Hardiness Zones using a seven-variable suitability index (Y, 0–100) rather than a single temperature threshold.

NRCan suitability formula

Natural Resources Canada calculates a plant hardiness suitability index (Y) from 0 to 100 using seven climate variables — not just extreme minimum temperature. The model was developed by Ouellet and Sherk and updated with modern climate normals.

Y = -67.62 + 1.734X₁ + 0.1868X₂ + 69.77X₃ + 1.256X₄ + 0.006119X₅ + 22.37X₆ − 0.01832X₇
  • X₁: Monthly mean of the daily minimum temperatures of the coldest month (°C).
  • X₂: Mean frost-free period above 0°C (days).
  • X₃: Rainfall index from June to November (function of rainfall in mm).
  • X₄: Monthly mean of the daily maximum temperatures of the warmest month (°C).
  • X₅: Winter factor based on January rainfall.
  • X₆: Mean maximum snow depth index (function of depth in mm).
  • X₇: Maximum wind gust recorded over a 30-year period.

Try the suitability calculator

Enter local climate normals to estimate the NRCan suitability index (Y) and approximate Canadian zone.

Select NRCan above to browse Canadian zones 0–9. Warm USDA zones (11–13) fall outside the Canadian map.

The Dormancy Engine

Hardiness is not a fixed label on a map — it is something the plant actively prepares for. Follow the four steps below to see how a rose bud senses autumn, switches off growth, seals itself in, and builds protection against frost.

Select a step in the sequence to explore the molecular triggers.

Climate pathology & dynamics

Pathogen pressure and physiological stress are highly temperature-dependent. These visualizations show risk windows for common rose ailments based on environmental conditions.

Pathogen growth vs. temperature

Blackspot (D. rosae) thrives between 18°C and 24°C with high humidity, while powdery mildew dominates warm, dry windows.

Thermal sunscald risk

Freeze-thaw critical point

Bark temperature can rise 20°C above ambient via insolation, triggering de-acclimation.

Emissivity of bark (ε)
~ 0.95
Insolation trigger
South-west exposure
Mechanical damage
Cambial rupture

The agronomic toolbox

Evidence-based methods to mitigate environmental stress, from physical insulation to nutritional hardening.

Minnesota tip

For USDA zones 2–4. Trench and bury the entire plant to use soil thermal mass through winter.

Labor intensity: high

Hilling / mounding

Soil or mulch mounded about 30 cm over the graft union protects basal buds when upper canes die back.

Labor intensity: moderate

Nutritional hardening

Reduce nitrogen about eight weeks before frost; increase potassium and magnesium to promote cane lignification.

Labor intensity: low

Rootstock climate compatibility

Rootstock Hardiness Soil profile Key constraint
R. multiflora High (northern climates) Acidic loam Salt sensitive; alkaline chlorosis
R. canina 'Inermis' Extreme (alpine) Lime-tolerant Slower to establish
R. fortuneana Tender (subtropical) Sandy / poor soils Frost intolerant

Featured cultivar notes

Select a climate bracket to explore varieties matched to cold, moderate, or warm winter conditions.