Delphinium Pacific Giants
Delphinium (Pacific Giant Group) · Ranunculaceae
Towering spires, taller than most people, packed with semi-double flowers in blue, violet, pink or white, each with a contrasting eye.
- Size
- 6 ft tall, 2½ ft wide
- Zones
- 3 to 7
- Light
- Full sun
- Flowers
- Late June to late July
- Pets
- Toxic (severe)
- Job in a bed
- Accent
A bed built around delphinium Pacific Giants
The planner designed this bed around delphinium Pacific Giants when this page was made: a 12 × 6 ft (3.7 × 1.8 m) cottage garden in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why delphinium Pacific Giants stands where it does.
The plants
- 1 Delphinium Pacific Giants × 3, blue
- 2 Moor grass 'Greenlee' × 5, tan
- 3 Coral bells 'Firefly' × 7, red
- 4 Stiff goldenrod × 3, yellow
- 5 Inkberry 'Gem Box' × 1, dark green leaves
- 6 Gloriosa daisy 'Indian Summer' × 3, yellow
- 7 Star of Persia × 5, purple
- 8 Hyacinth 'Delft Blue' × 12, blue
Why this plant
- Nothing here is unique to it. Its leaf, flower shape and colour are all on the plan already. Its case rests on where it stands and when it performs.
Why here
- Anchors a back corner. At 6 ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to inkberry 'Gem Box' (2½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one clump. A single spire is too slight to hold a place alone, so here the accent is a clump.
Why now
- In flower for six weeks. From late June to late July.
- Part of the bed's peak. With moor grass 'Greenlee', coral bells 'Firefly' and star of Persia in late June: 4 kinds at once. No week has more.
Planned as a cottage garden: 22 of the 22 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. The flowers run from mid April to early October: 25 weeks in all. The flowering is at its height in late June, with 4 kinds out together.
The planner's own design check: 8 Excellent, 7 Good, 2 Satisfactory.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where delphinium Pacific Giants goes in a border
At 6 ft it belongs at the back of a bed. In the planner's ten height classes it is very tall (5 to 6½ ft).
Its job: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.
The tall delphinium of the seed packet, raised in California in the 1930s. Magnificent and short-lived: treat it as a plant for two or three years, and stake every spire.
- The back of a traditional border
- Cottage gardens
- Cutting
What to plant with delphinium Pacific Giants
Plants recorded as good partners for it, and what each pairing does:
- Peony: a low mound at the foot of its spires; low enough (3 ft) to stand in front of it.
- Shasta daisy 'Becky': in flower together for four weeks, from early July; low enough (3½ ft) to stand in front of it.
- Lady's mantle: in flower together for three weeks, from late June; a low mound at the foot of its spires; low enough (18 in) to stand in front of it.
Questions about delphinium Pacific Giants
Does delphinium Pacific Giants need sun or shade?
Delphinium Pacific Giants grows in full sun (6 or more hours of direct sun a day).
It wants soil that stays evenly moist, rich in organic matter, and plenty of water.
What zones does delphinium Pacific Giants grow in?
USDA zones 3 to 7. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Above zone 7 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does delphinium Pacific Giants flower in my zone?
In zone 5 it flowers late June to late July. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Late June to early August |
|---|---|
| Zone 4 | Late June to early August |
| Zone 5 | Late June to late July |
| Zone 6 | Late June to late July |
| Zone 7 | Mid June to mid July |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should delphinium Pacific Giants be planted?
24 in (60 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 2½ ft (75 cm), so a group knits into one patch.
It grows 6 ft (180 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many delphinium Pacific Giants plants do I need?
At 24 in apart, set out in staggered rows:
- 3 to fill 10 square feet (about 1 m²)
- 6 for a single row 10 ft (3 m) long
- 10 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.
In the bed above, the planner used three in one group.
Is delphinium Pacific Giants poisonous to dogs and cats?
Yes: severe toxicity to people, dogs, cats and horses. All parts, especially the young growth and seeds, are highly poisonous if eaten.
Rated from the ASPCA. Where references disagree, the more cautious rating is used.
Is there a pet-safe plant like delphinium Pacific Giants?
These come closest to doing what delphinium Pacific Giants does, and no toxicity is recorded for them:
- Culver's root: the same job in a bed; 12 in shorter, flowers early July to mid August.
- Giant coneflower: the same job in a bed, the same size and the same flowering time; yellow, not blue, bold leaves, not medium.
- Blue vervain: the same job in a bed and the same colour; 24 in shorter, 8 in narrower.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
What flowers after delphinium Pacific Giants?
Delphinium Pacific Giants is over by late July. These start as it finishes and carry the same spot on, so it never goes flat:
- Hardy hibiscus: from late July to mid September, 5 ft tall.
- Tiger lily: from late July to late August, 4 ft tall, to stand in front of it and cover its fading stems.
- Garden phlox: from mid July to early September, 3½ ft tall, to stand in front of it and cover its fading stems.
What does delphinium Pacific Giants look like in winter?
Delphinium Pacific Giants dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.
More Delphinium
- Chinese delphinium 'Blue Butterfly' Delphinium grandiflorum 'Blue Butterfly'
- Delphinium Delphinium elatum
- Delphinium Magic Fountains Delphinium (Magic Fountains Series)
- Tall larkspur Delphinium exaltatum
In these guides
- Garden plants toxic to cats
- Garden plants toxic to dogs
- Tall perennials and grasses for the back of a border
- Plants with spires: vertical accents
- Plants with blue flowers
- Plants for a white garden
Every fact on record
- Type
- Perennial
- Size
- 6 ft (180 cm) tall, 2½ ft (75 cm) wide
- Plant
- 24 in (60 cm) apart
- Height class
- Very tall (5 to 6½ ft)
- Place in the bed
- Back
- Flowers
- Late June to late July; upright spires; blue, purple, pink, white
- Leaves
- Medium texture, herbaceous; green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 3 to 7
- Light
- Full sun
- Soil
- Rich, evenly moist
- Water
- High
- Feeding
- Moderate, in spring
- Family
- Ranunculaceae
Checked against ASPCA poison lists. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.