Striking biennial with intensely blue funnel-shaped flowers on bristly upright spikes. One of the most productive nectar plants in the British native flora.
Hardiness ratings
| System | Rating | Temperature range | How to read it |
|---|---|---|---|
| USDA hardiness zone | Zone 3–8 | −40 °C to −6.7 °C | Plant tolerates down to this zone |
| RHS hardiness rating | H7 | down to −20 °C | Plant needs at least this level of cold tolerance |
| Canadian plant hardiness zone | Zone 3–8 | −34 °C to −1 °C | Plant tolerates down to this zone |
| Australian (ANBG) zone | Zone 1–5 | −15 °C to 10 °C | Plant tolerates down to this zone |
Growing notes
- Among the highest nectar producers of any native UK wildflower — bees visit constantly throughout the day
- Thrives on poor, dry, gravelly soils where richer plants will not compete
- Self-seeds freely once established — strictly biennial, so allow some plants to set seed each year
Categories
Related plants
Cross-check Viper’s bugloss against your zones