Blue Delphinium Flower
Blue Delphinium Flower

Although Delphiniums are sometimes characterised as blue flowering giants, many other colors are available. Easily grown from seed, these wonderful plants are best suited to cooler zones. Also known as Larkspur.

These highly hybridised plants with tall flower spikes, especially the hybrid type elatum delphiniums are rightly called ‘Pacific Giants’. Colors range from white through to pink purple and of course the wonderful blues.

Delphiniun varieties include

  • Delphiniun elatum hybrids – Pacific Giants
  • Delphinium grandiflorum – Siberian Larkspur


Once the danger of frosts is over and the plants have been hardened off a little they are ready to plant into the garden.

The hybrids that we mainly plant have large flower heads and will need some support.

Individual bamboo canes, wire mesh for them to grow through are two methods.

Of course you can plant them between other perennials that they use for support if you like.

As for planting distance, the closer you plant them the taller they will grow. Also the more chance of mildew. So space them out for stronger healthy plant 15 inches apart.

After Flowering

Once the flowers have faded you have a choice, let the plants go, or cut the delphiniums back to a height of around 4 inches above the ground.

Hold off on the water and wait for them to reshoot. You just may get a second flush of flowers. Not as big as the first ones, but still a second flush of wonderful Delphiniums.

Delphinium Summary

  • Botanical Name : Delphinium elatum
  • Common Name : Larkspur
  • Family Name : Ranunculaceae
  • USDA Zone : 3 – 8
  • Flower colour – White to pink, blue and deep pink
  • Flowering Time – Spring to summer
  • Height : 24 inches
  • Spread : Clump Forming
  • Growth Rate : Fast
  • Soil : Humus rich, moist and well drained
  • Light : Full sun to Light shade.
  • Humidity : Medium to Low
  • Container Growing : Yes
  • Frost Tolerance : Yes
  • Drought Tolerant : No

Growing Delphiniums from seed

Best grown from fresh seed, Delphiniums are planted in spring. A few key points will have seeds germination well and producing lots of healthy plants.

Seed Germination

  1. Delphinium seeds are best planted in a sterile seed raising mix.
  2. Germination takes place at around 68 – 75F and at this stage the seedling trays need to be kept moist.
  3. You can use a tray that provides bottom heat to assist with germination and some gardeners like to cover the newly planted seeds with damp cardboard for the first 4 days.
  4. Seeds that are germinated in the dark, will need to be moved into light as soon as they do, otherwise you may lose them.
  5. Once germination has commenced seedlings can be removed to a ‘slightly cooler’ environment.
  6. As the second set of leaves appear, transplant into individual pots. We use the biodegradable pots that can be planted into the garden when the seedlings are ready.

You can find Delphinium seeds and plants for sale at the following nurseries

New millennium Delphiniums, New Zealand Hybrid Delphiniums, photos, cultivation notes and the opportunity to buy seed for these glorious English hybrid type elatum delphiniums.