Double perennial sunflower
Helianthus x multiflorus 'Flore Pleno' · Asteraceae
Fully double, golden-yellow flowers like dahlias, as wide as a hand, on stout, leafy stems from midsummer to autumn.
- Size
- 5 ft tall, 3 ft wide
- Zones
- 4 to 8
- Light
- Full sun
- Flowers
- Late July to mid September
- Pets
- Not checked
- Job in a bed
- Drift
A bed built around double perennial sunflower
The planner designed this bed around double perennial sunflower 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 double perennial sunflower stands where it does.
The plants
- 1 Double perennial sunflower × 1, yellow
- 2 Lingonberry × 3, pink
- 3 Carpathian bellflower × 9, blue
- 4 Foxglove beardtongue × 5, white
- 5 Gray's sedge × 3, green
- 6 Palm sedge × 3, green leaves
- 7 Tiger lily × 1, orange
- 8 Red spider lily × 10, red
Why this plant
- The only daisies. The others are bells, spires, globes and others. Shape reads at a distance, where colours blur.
- The only yellow.
Why here
- Anchors a back corner. At 5 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 tiger lily (4 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 9 weeks. From late July to mid September.
- Part of the bed's peak. With Carpathian bellflower, Gray's sedge and tiger lily in late July: 4 kinds at once. No week has more.
Planned as an English border: 6 of the 6 groups (100%) are drifts, longer along the bed than they are deep. Hot colours (yellow, orange and red) with pink and blue as the cool notes, and white and green to calm things between them. The front edge is finished with Carpathian bellflower and lingonberry.
The planner's own design check: 10 Excellent, 6 Good, 1 Satisfactory.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where double perennial sunflower goes in a border
At 5 ft it belongs at the back of a bed. In the planner's ten height classes it is tall (4 to 5 ft).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
An old cottage garden plant, sterile and long in flower. It makes a solid block of yellow at the back of a border and needs dividing every third year to stay vigorous.
- The back of a traditional border
- Cutting
- Late-summer colour
What to plant with double perennial sunflower
Plants recorded as good partners for it, and what each pairing does:
- New England aster: purple against yellow, opposite each other on the colour wheel, if you choose those colours, in flower together for three weeks; happy in the same moist soil.
- Garden phlox: purple against yellow, opposite each other on the colour wheel, if you choose those colours, in flower together for seven weeks; happy in the same moist soil.
- Feather reed grass 'Karl Foerster': in flower together for nine weeks, from late July; happy in the same moist soil.
Questions about double perennial sunflower
Does double perennial sunflower need sun or shade?
Double perennial sunflower 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 a good soak in dry spells.
What zones does double perennial sunflower grow in?
USDA zones 4 to 8. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).
Above zone 8 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 double perennial sunflower flower in my zone?
In zone 5 it flowers late July to mid September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 4 | Early August to mid September |
|---|---|
| Zone 5 | Late July to mid September |
| Zone 6 | Late July to mid September |
| Zone 7 | Mid July to mid September |
| Zone 8 | Mid July to mid 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 double perennial sunflower 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 5 ft (150 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many double perennial sunflower 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 a group of three or five, with a second group further along in the other number.
In the bed above, the planner used one in one group.
Is there a native plant like double perennial sunflower?
Double perennial sunflower is not native to North America. These North American natives come closest to doing its job:
- Cutleaf coneflower: the same job in a bed, the same flowering time and the same colour; 20 in taller, bold leaves, not medium.
- Flat-topped aster: the same job in a bed, the same size and the same flowering time; white, not yellow.
- Sneezeweed: the same job in a bed, the same flowering time and the same colour; 12 in shorter, 6 in narrower.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Will double perennial sunflower spread?
It spreads sideways, by runners or roots; the risk of it taking over is moderate. Spreads by creeping roots into a wide clump. Divide it every three years.
What flowers after double perennial sunflower?
Double perennial sunflower is over by mid 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, to stand in front of it and cover its fading stems.
- Montauk daisy: from mid September to late October, 3 ft tall, to stand in front of it and cover its fading stems.
- Tatarian aster 'Jindai': from early October to early November, 4 ft tall.
What does double perennial sunflower look like in winter?
Double perennial sunflower 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 Helianthus
- Maximilian sunflower Helianthus maximiliani
- Sunflower 'Lemon Queen' Helianthus 'Lemon Queen'
- Swamp sunflower Helianthus angustifolius
- Willowleaf sunflower 'First Light' Helianthus salicifolius 'First Light'
- Woodland sunflower Helianthus divaricatus
In these guides
Every fact on record
- Type
- Perennial
- Size
- 5 ft (150 cm) tall, 3 ft (90 cm) wide
- Plant
- 2½ ft (75 cm) apart
- Height class
- Tall (4 to 5 ft)
- Place in the bed
- Back
- Flowers
- Late July to mid September; daisies; yellow
- Leaves
- Medium texture, herbaceous; dark green
- Shape
- Upright, spreading
- Hardy in
- USDA zones 4 to 8
- Light
- Full sun
- Soil
- Rich, evenly moist
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Asteraceae
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.