Climate matters. This page is a practical baseline. Confirm cultivar, local frost/heat conditions, mature size and regional restrictions before planting.
Sweet Pea — Growing reference
| Scientific name | Lathyrus odoratus |
|---|---|
| Seed germination (days) | 10–21 |
| Soil temperature for germination (°C) | 12.8–18.3 |
| First harvest or flowering (days) | 60–90 |
| Measured from | Seed |
| Plant spacing (cm) | 10.2–15.2 |
| Mature height (cm) | 61–182.9 |
| Mature spread (cm) | 15.2–30.5 |
| USDA hardiness zones | 3–9 |
| Light | Full sun |
| Water | Moderate |
| Sowing method | Direct sow |
Growing directions
Nick or soak seeds overnight before sowing 1 in deep in cool, enriched soil at the base of a trellis. Sweet peas perform best during cool weather and decline as summer heat arrives — sow as early as possible. Cut flowers frequently, as even a few fading blooms left on the plant will trigger seed set and halt blooming. Provide sturdy support from the start, as vines climb to 4–6 ft.
Source and local conditions
Typical planning ranges from OpenPlantDB (CC0). Cultivar, climate, season and growing method can change these values. Confirm the seed label and local guidance before planting.
Source & verification
OpenPlantDB · CC0