Giant scabious
Cephalaria gigantea · Dipsacaceae
Pale primrose-yellow pincushions sway on bare, branching stems far above head height, from a broad clump of coarse leaves.
- Size
- 6½ ft tall, 3 ft wide
- Zones
- 3 to 7
- Light
- Full sun
- Flowers
- Late June to early August
- Pets
- Not checked
- Job in a bed
- Weaver
A bed built around giant scabious
The planner designed this bed around giant scabious when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why giant scabious stands where it does.
The plants
- 1 Giant scabious × 1, yellow
- 2 Winter heath × 11, pink
- 3 Alpine aster × 5, purple
- 4 False sunflower 'Summer Sun' × 3, yellow
- 5 Brown-eyed Susan × 5, yellow
- 6 Spurge 'Chameleon' × 3, purple leaves
- 7 Hardy gladiolus × 4, pink
- 8 Grape hyacinth × 8, blue
Why this plant
- The only bold leaves here. The rest are fine and medium. A change of leaf keeps plants distinct when nothing is in flower.
- The only globes. The others are bells, daisies and spires. Shape reads at a distance, where colours blur.
Why here
- Anchors a back corner. At 6½ 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 hardy gladiolus (2½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A feature plant is seen as an object, and needs clear ground around it.
Why now
- In flower for 7 weeks. From late June to early August.
- Part of the bed's peak. With false sunflower 'Summer Sun' and brown-eyed Susan in late July: 3 kinds at once. No week has more.
Planned as an English border: 5 of the 5 groups (100%) are drifts, longer along the bed than they are deep. Yellow runs through the planting: 3 of the 7 kinds grown for their flowers have it. Winter heath and alpine aster finish the front edge.
The planner's own design check: 11 Excellent, 5 Good, 1 Needs revision. Its weakest point is height and scale: Heights average about 10 in at the front, 20 in in the middle and 4 ft at the back. Along the back row the heights step up and down, between 2½ ft and 6½ ft, and no two neighbours are the same height. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where giant scabious goes in a border
At 6½ ft it belongs at the back of a bed. In the planner's ten height classes it is very tall (5 to 6½ ft). It is airy enough to see through, so it can also come forward and veil what is behind it.
Its job: weaver. A light, airy plant threaded singly between sturdier ones to knit the planting together.
A giant you can see through, so it can stand in the middle of a border and not block the view. The soft yellow works with every colour. It needs space at the base and no staking.
- Airy height in a large border
- Cottage gardens
- Bees and butterflies
What to plant with giant scabious
Plants recorded as good partners for it, and what each pairing does:
- Delphinium: purple against yellow, opposite each other on the colour wheel, if you choose those colours, in flower together for four weeks; medium leaves against its bold ones.
- Peony: flowers first, late May to late June, so the spot is never empty; medium leaves against its bold ones; low enough (3 ft) to stand in front of it.
- Feather reed grass 'Karl Foerster': in flower together for seven weeks, from late June; fine leaves against its bold ones; happy in the same moist soil.
Questions about giant scabious
Does giant scabious need sun or shade?
Giant scabious grows in full sun (6 or more hours of direct sun a day).
It wants soil that stays evenly moist, of average fertility, and a good soak in dry spells.
What zones does giant scabious 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 giant scabious flower in my zone?
In zone 5 it flowers late June to early August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Early July to mid August |
|---|---|
| Zone 4 | Early July to mid August |
| Zone 5 | Late June to early August |
| Zone 6 | Late June to early August |
| Zone 7 | Late June to early August |
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 giant scabious be planted?
2½ ft (75 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 3 ft (90 cm), so a group knits into one patch.
It grows 6½ ft (200 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many giant scabious plants do I need?
At 2½ ft apart, set out in staggered rows:
- 2 to fill 10 square feet (about 1 m²)
- 5 for a single row 10 ft (3 m) long
- 6 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, threaded between sturdier plants.
In the bed above, the planner used one in one group.
Is there a native plant like giant scabious?
Giant scabious is not native to North America. These North American natives come closest to doing its job:
- Grey-headed coneflower: the same job in a bed, the same flowering time and the same colour; 2½ ft shorter, 14 in narrower.
- Giant coneflower: the same flowering time and the same colour; an accent, not a weaver, 6 in narrower.
- Spotted Joe-Pye weed: a drift, not a weaver, 12 in shorter.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
What flowers after giant scabious?
Giant scabious is over by early August. These start as it finishes and carry the same spot on, so it never goes flat:
- Switchgrass 'Northwind': from early August to early October, 5½ ft tall.
- Little bluestem 'Standing Ovation': from early August to mid September, 3½ ft tall, to stand in front of it and cover its fading stems.
- Lilyturf: from early August to mid September, 16 in tall, to stand in front of it and cover its fading stems.
What does giant scabious look like in winter?
Giant scabious 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.
In these guides
Every fact on record
- Type
- Perennial
- Size
- 6½ ft (200 cm) tall, 3 ft (90 cm) wide
- Plant
- 2½ ft (75 cm) apart
- Height class
- Very tall (5 to 6½ ft)
- Place in the bed
- Back, or further forward: it is airy enough to see through
- Flowers
- Late June to early August; globes; yellow, cream
- Leaves
- Bold texture, herbaceous; green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 3 to 7
- Light
- Full sun
- Soil
- Average, evenly moist
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Dipsacaceae
Checked against VASCAN (plants of Canada). 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.