Climate matters. This page is a practical baseline. Confirm cultivar, local frost/heat conditions, mature size and regional restrictions before planting.
Penstemon — Growing reference
| Scientific name | Penstemon digitalis |
|---|---|
| Seed germination (days) | 14–28 |
| Soil temperature for germination (°C) | 15.6–21.1 |
| First harvest or flowering (days) | 90–365 |
| Measured from | Seed |
| Plant spacing (cm) | 45.7–61 |
| Mature height (cm) | 61–121.9 |
| Mature spread (cm) | 45.7–61 |
| USDA hardiness zones | 3–8 |
| Light | Full sun |
| Water | Low |
| Sowing method | indoor-start |
Growing directions
Cold-stratify seeds for 4 weeks in damp medium in the refrigerator before sowing indoors for best germination; transplant after the last frost into well-drained to dry soil. Penstemon thrives in poor, gravelly soil and is one of the most important native nectar plants for hummingbirds and native bees. The tubular white to pale pink flowers appear in late spring to early summer; deadhead to a basal rosette of leaves after bloom. Excellent drainage is critical — wet winter conditions are the leading cause of plant loss.
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