Knautia
Knautia macedonica ·
Dark crimson pincushions on thin, branching stems float above the border from June to September. It is short-lived and seeds itself.
- Size
- 24 in tall, 18 in wide
- Zones
- 5 to 9
- Light
- Full sun
- Flowers
- Late June to early September
- Pets
- Not checked
- Job in a bed
- Weaver
A bed built around knautia
The planner designed this bed around knautia 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 715 that suit those conditions and its dry soil, and says below why knautia stands where it does.
The plants
- 1 Knautia × 2, red
- 2 Winter heath × 8, pink
- 3 Candytuft × 3, white
- 4 Stiff goldenrod × 3, yellow
- 5 Smooth aster 'Bluebird' × 4, blue
- 6 Silver sage × 1, silver leaves
- 7 Ornamental onion 'Purple Sensation' × 5, purple
- 8 Star of Persia × 5, purple
Why this plant
- The only red.
Why here
- In the middle. At 24 in it is the step between winter heath (10 in) in front and smooth aster 'Bluebird' (3½ ft) behind: each is seen over the one before.
- 2 plants in 2 places. An accent is a punctuation mark: the repeat along the bed gives it rhythm.
Why now
- In flower for 12 weeks. From late June to early September.
- Fills a gap. For 7 of those weeks nothing else on the plan is in flower.
Planned as a cottage garden: 21 of the 21 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. Silver sage, winter heath and candytuft finish the front edge. Winter heath is the plant there is most of: 8 of the 31.
The planner's own design check: 12 Excellent, 5 Good. 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 knautia goes in a border
At 24 in it belongs in the middle of a bed. In the planner's ten height classes it is medium short (18 to 24 in). 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.
The stems are so thin that the flowers seem unattached, like a scatter of red buttons. Weave it through grasses and pale flowers; a solid block of it loses the effect.
- Dark red dots threaded through other plants
- Naturalistic and meadow-style planting
- Cut flowers
What to plant with knautia
Plants recorded as good partners for it, and what each pairing does:
- Blue oat grass: in flower together for three weeks, from late June; happy in the same dry soil.
- Salvia 'May Night': in flower together for four weeks, from late June.
- Yarrow 'Moonshine': in flower together for eight weeks, from late June; happy in the same dry soil.
Questions about knautia
Does knautia need sun or shade?
Knautia grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, of average fertility, and little watering once settled.
What zones does knautia grow in?
USDA zones 5 to 9. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does knautia flower in my zone?
In zone 5 it flowers late June to early September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 5 | Late June to early September |
|---|---|
| Zone 6 | Late June to early September |
| Zone 7 | Mid June to early September |
| Zone 8 | Mid June to early September |
| Zone 9 | Early June to early September |
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 knautia be planted?
18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.
It grows 24 in (60 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many knautia plants do I need?
At 18 in apart, set out in staggered rows:
- 5 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 17 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 two in two groups.
Is there a native plant like knautia?
Knautia is not native to North America. These North American natives come closest to doing its job:
- Mexican hat: the same job in a bed, the same flowering time and the same colour; 4 in narrower, fine leaves, not medium.
- Whorled milkweed: the same job in a bed, the same size and the same flowering time; white, not red, fine leaves, not medium.
- Flowering spurge: the same job in a bed and the same flowering time; 6 in taller, white, not red.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Will knautia spread?
It seeds itself about; the risk of it taking over is moderate. Short-lived, but keeps going by self-seeding. Thin or move seedlings where they are not wanted.
What flowers after knautia?
Knautia is over by early September. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall.
- Bottle gentian: from late August to early October, 20 in tall.
- October daphne: from mid September to late October, 8 in tall, to stand in front of it and cover its fading stems.
What does knautia look like in winter?
Knautia 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
- 24 in (60 cm) tall, 18 in (45 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Medium short (18 to 24 in)
- Place in the bed
- Middle, or further forward: it is airy enough to see through
- Flowers
- Late June to early September; globes; red
- Leaves
- Medium texture, herbaceous; green
- Shape
- Upright, self-seeding
- Hardy in
- USDA zones 5 to 9
- Light
- Full sun
- Soil
- Average, dry and sharply drained
- Water
- Low
- Feeding
- None needed
Not yet checked against an outside reference: its figures rest on general horticultural knowledge. 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.