When to Plant Sweet Peas
Fragrant climbing annual with ruffled blooms in pastel and jewel tones. The most intensely perfumed garden flower.
The Short Answer
How to Grow Sweet Peas
Sweet peas produce the most intensely perfumed flowers in the annual garden — the fragrance is legendary. Soak seeds overnight in water before planting to soften the hard seed coat. Plant as early in spring as possible — sweet peas need cool temperatures to establish and bloom. Provide 6-8 foot trellis, netting, or string for the tendrils to climb. Cut flowers aggressively — this stimulates more production. Once seed pods form, the plant stops blooming. Sweet peas despise heat: when summer temperatures arrive, the show is over. In mild-winter areas, sow in fall for early spring bloom.
Starting Seeds Indoors
Begin sweet peas seeds indoors 6 weeks before your average last frost date. Seeds need soil temperatures of at least 40°F to germinate, which typically takes 10-14 days. Provide 12 hours of light per day using a south-facing window or grow lights.
Transplanting
Move seedlings outside 4 weeks before your last frost date, once soil temperatures reach 40°F. Harden off seedlings for 5 days before transplanting by gradually exposing them to outdoor conditions.
Direct Sowing
Sweet Peas can be direct sown 6 weeks before your last frost date. Plant seeds 1" deep, spaced 6" apart.
Growing Tips
Soak seeds overnight before planting. Provide trellis or netting — vines climb 6-8 feet. Cut flowers aggressively to keep plants producing. They stop blooming in summer heat — plant early for maximum bloom time.
Companion Planting
Good companions:
Sweet Peas Planting Dates by State
Click your state for sweet peas planting dates specific to your location:
Last reviewed: March 29, 2026