Delphinium
Slugs and snails can strip tender new spring shoots overnight, so bait or use barriers as soon as growth appears. Needs a sheltered spot out of strong wind and staking for its tall flower spikes; keep soil evenly moist to help resist powdery mildew.
- Sun
- full sun
- Water
- moderate
- Spacing
- 45cm
- Difficulty
- intermediate
- Grows in
- Whangārei / Northland, Auckland, Hamilton / Waikato, Tauranga / Bay of Plenty, Gisborne, Napier / Hawke's Bay, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson, Tasman, Blenheim / Marlborough, West Coast, Christchurch / Canterbury, Dunedin / Otago, Invercargill / Southland
- Mature height
- 1.5m
- Flowering season
- Jan, Nov, Dec
- Common diseases
- Powdery mildew, Crown rot
- Common pests
- Slugs and snails, Aphids
When to plant by region
In Whangārei / Northland, Auckland, Tauranga / Bay of Plenty, Gisborne and Napier / Hawke's Bay: February-March. In Hamilton / Waikato, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson and Tasman: February-March and September. In Blenheim / Marlborough, West Coast, Christchurch / Canterbury, Dunedin / Otago and Invercargill / Southland: September-October.
Growing stages
Germination & planting
- Needs a sheltered spot out of strong wind to protect its tall flower spikes
- Space plants around 45cm apart in full sun
Establishment
- Slugs and snails can strip tender new spring shoots overnight, so bait or use barriers as soon as growth appears
- Keep soil evenly moist to help young plants resist powdery mildew
Vegetative growth
- Stake tall flower spikes early, before they're toppled by wind
- Crown rot can set in if soil stays waterlogged, so keep drainage good
- Powdery mildew can appear on foliage in humid conditions
FloweringNovember to January
- Keep soil evenly moist through flowering to help resist powdery mildew
- Aphids can cluster on flower spikes and buds
- Staking remains important as flower spikes get heavy in bloom
Dieback & dormancy
- Cut back spent flower stems once blooms fade
- Watch for slugs and snails on fresh shoots again as new growth restarts the following spring