Sweet pea

Lathyrus odoratus

Annual twining climber with paired pinnate leaflets, terminal tendrils, and stems of fragrant pea-flowers in almost every colour through summer. The classic British cottage-garden cut-flower annual.

Hardiness ratings

Sweet pea hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 2–11 −45.6 °C to 10 °C Zones where it can be grown as an annual — not a frost-tolerance rating
RHS hardiness rating H3 −5 °C to 1 °C Plant needs at least this level of cold tolerance
Canadian plant hardiness zone Zone 2–9 −40 °C and warmer Zones where it can be grown as an annual — not a frost-tolerance rating
Australian (ANBG) zone Zone 1–7 −15 °C and warmer Zones where it can be grown as an annual — not a frost-tolerance rating

As a tender annual, Sweet pea doesn't overwinter — the zone range shows where the growing season supports it. See the RHS rating for its actual cold tolerance.

Growing notes

  • Plant against trellises, wigwams, and pea-sticks — among the most popular cut flowers of summer, lasts well in the vase
  • Strongly fragrant — choose old-fashioned cultivars (‘Cupani’, ‘Painted Lady’) for the strongest scent, modern Spencer cultivars trade fragrance for flower size
  • Sow autumn for the earliest, longest, and most prolific flowering the following summer

Pet caution: Sweet pea is listed as potentially harmful to cats and/or dogs. Keep pets from grazing on it, and contact a vet if you suspect your animal has eaten some.

Categories

Related plants

Cross-check Sweet pea against your zones

Reference

Sweet pea on Wikipedia