Delphinium
flower
⚠️ ALL PARTS TOXIC. Tall stately cottage garden spires — stake in windy spots. Cut back to basal foliage after first bloom for a second fall flush. Thrives in cool summers.
At a glance
- USDA Zones
- 3–7
- Sun
- Full sun (6+ hrs)
- Water
- Medium — water when top inch of soil is dry
- Soil
- Loam
- pH
- Neutral, alkaline
- Spacing
- 18 in. between plants
- Space needed
- A 2×2 ft block of the bed
Planting & harvest windows
Northern Hemisphere timing. Adjust ±4–6 weeks based on your last/first frost dates.
| Activity | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Plant | ||||||||||||
| Harvest |
Plant Harvest
Good companions
Recommended varieties
- Pacific Giantsboth
Classic tall 5–6 ft spires in blue, purple, white, and pink.
- Magic Fountainsboth
Compact 2.5 ft — excellent for raised beds without staking.
- Black Knightboth
Deep, rich violet-purple with a black bee center.
Add Delphinium to your raised bed — the planner handles spacing and companion warnings automatically.
Open the planner →