UK hardiness lookup
Jersey (St Helier) (JE) — RHS hardiness H2
Jersey (St Helier), England · 250-day frost-free season
Frost dates and growing season for JE
| RHS hardiness rating | H2 |
|---|---|
| Average last spring frost | mid-March |
| Average first autumn frost | late November |
| Growing season length | ~250 days |
| Temperature range (C) | minimum 1-5 °C |
| Temperature range (F) | minimum 34-41 °F |
| USDA equivalent | Roughly USDA zone 10 (-1 to 4 °C minimum). |
UK frost dates come from Met Office regional climate averages (1991-2020). Frost pockets, valleys, and exposed elevation can shift Jersey (St Helier)-area gardens a full band colder than the regional figure. Coastal and urban gardens run a band warmer.
What grows at RHS H2 in Jersey (St Helier)
Frost-tender plants that survive in the UK only where the sea moderates winter lows to above 1 °C.The RHS rates plants — not regions — so check the rating on each plant's tag against this H2 baseline. Anything rated H2 or hardier (numerically higher) should overwinter reliably in a typical Jersey (St Helier) year.
- Echium pininana
- Geranium maderense
- Aeonium (outdoors year-round in Scilly)
- Hedychium (ginger lilies)
- Banana (Musa basjoo with protection — Ensete in milder spots)
- Tree ferns (Dicksonia antarctica) in shelter
- Watsonia
- Salvia leucantha
- Lantana camara
- Agapanthus africanus (the tender evergreen forms)
When to plant in Jersey (St Helier)
Sowing, transplant, and harvest dates for the most common edible crops, calibrated to RHS H2 timing:
- When to plant tomatoes at RHS H2
- When to plant peppers at RHS H2
- When to plant basil at RHS H2
- When to plant garlic at RHS H2
- When to plant lettuce at RHS H2
- When to plant bush beans at RHS H2
- When to plant cucumbers at RHS H2
- When to plant summer squash at RHS H2
- When to plant peas at RHS H2
- When to plant carrots at RHS H2
For a one-shot starting point: tomatoes go outside from the mid-March window onwards; garlic goes in 4-6 weeks before late November; brassicas and salads can run on either side of the frost window with fleece in cold snaps.
Local microclimate notes
Postcode-area ratings are a baseline — your actual garden can sit a band warmer or colder. Urban heat-island effect lifts inner-city gardens; frost pockets at the bottom of slopes drop them. If you can record your own lowest winter temperature for a couple of seasons, that beats any regional average for planning.
For US gardeners reading UK references: RHS H2 is Roughly USDA zone 10 (-1 to 4 °C minimum). — see the matching USDA Zone 10 guide for the US-side planting calendar.
Source and methodology
Hardiness rating from the Royal Horticultural Society hardiness rating scale. Frost-date averages from Met Office UK climate averages (1991-2020), matched to the nearest representative regional station for postcode JE. Plant recommendations curated by the Growli editorial team. Last review 2026-05-19.
Other postcode areas in England
- EC1 — London (Clerkenwell) (RHS H4)
- EC2 — London (City) (RHS H4)
- WC1 — London (Bloomsbury) (RHS H4)
- WC2 — London (Covent Garden) (RHS H4)
- W1 — London (Mayfair / Soho) (RHS H4)
- SW1 — London (Westminster / Belgravia) (RHS H4)
- NW1 — London (Camden) (RHS H4)
- N1 — London (Islington) (RHS H4)
- E1 — London (Whitechapel) (RHS H4)
- SE1 — London (Southwark) (RHS H4)
- SE10 — London (Greenwich) (RHS H4)
- SW19 — London (Wimbledon) (RHS H4)
- Browse all UK postcode areas