How far apart should I plant Delphinium?

About 60 cm (24 in) apart, centre to centre. A mature plant spreads 50–90 cm (20–35 in).

Does Delphinium need full sun?

Full sun: at least 6 hours of direct sun a day.

How much water does Delphinium need?

Moderate water. Drought tolerance is none and waterlogging tolerance low.

How cold-hardy is Delphinium?

It tolerates about -34 °C (-29 °F) once established, roughly USDA zone 4.

When does Delphinium flower?

From about June for 3–5 weeks (northern hemisphere; later in cold climates, earlier in warm ones).

What grows well with Delphinium?

There is no well-documented companion pairing for Delphinium. Group it with plants that like the same sun (full sun) and water (moderate).

Delphinium Delphinium elatum hybrids

Delphinium (Delphinium elatum hybrids) is a deciduous perennial flowering plant in the Ranunculaceae family, native to Garden hybrids; Delphinium elatum is native to mountains of central and southern Europe and Siberia. It grows 1.2–1.8 m (3.9–5.9 ft) tall and 50–90 cm (20–35 in) wide, wants full sun and moderate water, and is hardy to about -34 °C (-29 °F). Space plants about 60 cm (24 in) apart.

Plan Delphinium in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.

Delphinium at a glance

Type	Perennial flowering plant, deciduous
Family	Ranunculaceae
Mature height	1.2–1.8 m (3.9–5.9 ft)
Mature spread	50–90 cm (20–35 in)
Spacing	60 cm (24 in) centre to centre
Sun	Full sun, at least 6 h of direct sun a day
Water	Moderate; drought tolerance none, waterlogging tolerance low
Soil pH	6–7.5
Cold hardiness	About -34 °C (-29 °F) once established (roughly USDA zone 4)
Heat stress	Likely above about 25 °C (77 °F)
Flowering	from about June for 3–5 weeks (northern hemisphere; later in cold climates, earlier in warm ones)
Wind tolerance	None
Pollinator value	High
Edible	Not grown as food
Native to	Garden hybrids; Delphinium elatum is native to mountains of central and southern Europe and Siberia
Common in gardens of	🇬🇧 United Kingdom, 🇺🇸 United States, 🇩🇪 Germany, 🇳🇴 Norway

Is Delphinium toxic?

People: severely toxic
Cats: severely toxic
Dogs: severely toxic
Parts: all parts, young leaves, seeds

Diterpenoid alkaloids (delphinine and relatives) are neurotoxic and can cause vomiting, weakness, and heart and breathing problems if eaten.

If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.

Companion planting: what to grow with Delphinium

No well-documented helpful pairing. Group it with plants that like full sun and moderate water.

Keep apart or take care

caution With Larkspur: Delphinium and larkspur share the same slugs, snails and mildew problems, and both are poisonous, so keep them away from play areas and grazing pets. Evidence C

See Delphinium in a botanical garden

It grows in these sample gardens, which you can walk through in 3D:

Questions about Delphinium

How far apart should I plant Delphinium?: About 60 cm (24 in) apart, centre to centre. A mature plant spreads 50–90 cm (20–35 in).
Does Delphinium need full sun?: Full sun: at least 6 hours of direct sun a day.
How much water does Delphinium need?: Moderate water. Drought tolerance is none and waterlogging tolerance low.
How cold-hardy is Delphinium?: It tolerates about -34 °C (-29 °F) once established, roughly USDA zone 4.
When does Delphinium flower?: From about June for 3–5 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
Is Delphinium poisonous to cats and dogs?: For cats it is severely toxic; for dogs severely toxic; for people severely toxic. Diterpenoid alkaloids (delphinine and relatives) are neurotoxic and can cause vomiting, weakness, and heart and breathing problems if eaten.
What grows well with Delphinium?: There is no well-documented companion pairing for Delphinium. Group it with plants that like the same sun (full sun) and water (moderate).

Sources and evidence

Evidence grade B (B: extension service or peer-reviewed).

RHS Plant Finder, Royal Horticultural Society
Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
ASPCA Toxic and Non-Toxic Plant List, ASPCA

Notes and assumptions

Typical garden-form values; cultivars and local conditions differ.
Elatum-group hybrids are short-lived (3 to 5 years) and need staking.

Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.

Related plants

Hellebore (Lenten rose) Helleborus x hybridus
Common columbine Aquilegia vulgaris
Japanese anemone Anemone hupehensis
Larkspur Consolida ajacis
Love-in-a-mist Nigella damascena
Globeflower Trollius europaeus
Christmas rose Helleborus niger
Persian buttercup Ranunculus asiaticus