Photo: Alvesgaspar, CC BY-SA 3.0 · source

Perennial · Asteraceae

False sunflower

Heliopsis helianthoides

In other languages: Zonneoog (Nederlands) · Héliopsis (Français)

False sunflower is a sturdy perennial from the prairies and open woods of North America. It forms upright clumps 1–1.2 m tall with rough, dark green leaves and from July into September produces a mass of golden-yellow flowers that look like small sunflowers. Gardeners love it because it flowers for a long time, is easy, grows in almost any soil and gives excellent cut flowers. Bees and butterflies flock to the flowers, and in winter birds feed on the seeds. Well-known varieties include ‘Sommersonne’, with single to semi-double golden flowers, and ‘Summer Nights’, with dark stems and a reddish-brown centre.

Updated on 9 October 2026

Light
Full sun
warm and bright
Moisture
Dry to normal
no wet feet
Legal basis
Sand, loam or clay
any pH
Hardiness
Fully hardy
down to -35 °C
Size
1.2 m
tall, 0.6 m wide
Flowering
July–September

Key facts
Pruning months	March
Height	1.2 m
Native to Belgium	No, planted
Good for bees, butterflies and birds	Yes, for bees, butterflies and birds
Poisonous to people and pets	Not known to be poisonous
Flowering	July–September

Identify

False sunflower: how do you recognise it?

Habit: Upright, compact clump 1–1.2 m tall and about 60 cm wide, with stiff, branching stems.
Leaves: Opposite, oval to lance-shaped, toothed and rough to the touch; dark green.
Flower: Flower heads 5–8 cm across with golden-yellow rays around a domed yellow to brownish-yellow centre. Single or semi-double, from July to September.
Fruit: Seed heads that stay on through autumn and winter; goldfinches love them.
Roots: A dense, fibrous root clump that does not run.

Flowering: July–September · Sowing: March–April · Plants: March–May and September–October · Pruning: March

In your garden

Why grow it?

Flowers from July into September, and longer still if you remove faded flowers.
Bees and butterflies find nectar and pollen; birds eat the seeds in winter.
An excellent cut flower that lasts well in a vase.
Sturdy, easy and very hardy; it grows on sand, loam and clay.
Brings warm yellow colour to the late-summer border, with grasses and other prairie plants.

False sunflower: where does it grow best?

Full sun: in shade the stems go floppy and it flowers less.
Any free-draining garden soil: sand, loam or clay, acid to chalky.
Dry to moderately moist. Once established it copes well with drought.
In very rich soil it grows tall and flops: support is needed there.
Plant 50–60 cm apart, ideally in groups of three or five.

Light: Sun
Soil type: Sand, loam or clay
Acidity: Not fussy
Moisture: Dry or normal
Size: 1.2 m tall, 0.6 m wide
Hardiness: Hardy (to -35 °C)

Goes well with

Purple coneflower: Another prairie plant that flowers at the same time: pink next to golden yellow.
Globe thistle: Steel-blue globes as a contrast to the yellow.
Switchgrass: Airy plumes and autumn colour between the sturdy clumps; also from the prairie.
Woodland sage: Blue spikes at the front of the border for a warm colour contrast.
Michaelmas daisy: Takes over in September and October with purple and blue.

Maintenance

False sunflower: when and how to plant it?

Plant in March–May and September–October.

Plant from March to May or in September–October.
Dig a hole twice as wide as the root ball and loosen the soil well. On poor sand add a spadeful of compost; on rich soil add nothing.
Set the plant at the same depth as it was in its pot and firm the soil well.
Leave 50–60 cm between plants.
Water generously straight away and keep the soil moist for the first few weeks.
Spread a thin layer of mulch around the base, but keep it away from the stems.

Care

Water: In the first year during dry spells. After that only in long dry periods; it then also flowers for longer.
Feeding: A layer of compost in April is enough. Extra fertiliser gives long, floppy stems.
Support: In rich soil or a windy spot: put a plant support or a few twiggy sticks around the clump in May.
Deadheading: Cut faded flowers back to just above a leaf or side bud: new flowers will follow. From September, leave the last seed heads for the birds.
Cut flowers: Cut stems in the morning when the flower has just opened and put them in water straight away.
Dividing: Every 4–5 years in spring, when the clump flowers less in the middle.

Tip: Put supports in place in May, while the stems are still short: they grow up through them unseen and will not flop in August.

False sunflower: when to prune it?

Pruning months: March.

When: Cut the old stems back in March, just before the new shoots appear. Leave them standing over winter for birds and insects.

How:

Cut all dead stems down to 5–10 cm above the ground.
In summer, cut faded flowers back to just above a leaf or side bud.
Want a shorter, sturdier plant? In late May, shorten half of the stems by a third: they branch and flower a little later.
Remove thin, weak stems at the base.

Caution: Do not cut back in autumn: the seed heads are winter food for goldfinches and insects overwinter in the hollow stems.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division: In March–April: lift the clump and split it with a spade into pieces, each with a few buds and roots. Replant straight away and water.
Seed: Indoors in March–April at 18–20 °C, lightly covered. Plant the young plants out in May. Named varieties do not always come true from seed.

False sunflower: how does it get through the winter?

Hardy to −35 °C.

Very hardy, to about −35 °C: no protection needed.
Leave the stems and seed heads over winter: birds eat the seeds and they look lovely with frost on them.
It also survives winter in a large pot; do stand the pot on feet so water can drain away.

Diseases and pests

Flopping stems: Mainly in rich soil, in shade or after a downpour. Support in good time, do not feed and choose a sunny spot.
Powdery mildew: White powder on the leaves in late summer, especially in dry spells. Water at the base, leave space between plants and remove affected leaves.
Aphids: Colonies on the stem tips in June–July. Hose them off with water; ladybirds and birds help out.
Slugs: They eat young shoots in spring. Pick them off in the evening and keep the soil around young plants open.

Through the year

March: Cut back old stems. Plant or divide. Sow indoors.
April: Plant. Sow indoors. Give compost.
May: Plant out young plants. Put in supports in rich soil.
June: Water in dry spells. Watch for aphids.
July: Flowering starts. Cut flowers for the house. Deadhead.
August: In full flower. Deadhead. Water during long dry spells.
September: Last flowers. Plant. Leave the seed heads.
October: Plant. Leave the stems for the birds.
December: Rest. Goldfinches feed on the seed heads.

Use

Good for wildlife

Bees: Nectar and pollen for honeybees and wild bees.
Butterflies: Nectar for butterflies.
Birds: Berries, seeds or insects as food, or a place to nest.

You and this species

Did you know?

Heliopsis means ‘looking like the sun’ (Greek helios, sun, and opsis, appearance); helianthoides means ‘like a sunflower’.
False sunflower belongs to the same family as the sunflower, but to a different genus. Unlike the sunflower, its yellow ray florets also set seed.
In North America it grows wild in prairies, along woodland edges and on roadsides.

Garden plants · All species