Willow-leaved sunflower

Willow-leaved sunflower: how do you recognise it?

Habit

Tall, upright clump 1.5–2 m high and about 90 cm wide, with sturdy, unbranched stems.

Foliage

Narrow, linear and willow-like, 10–15 cm long, dark green and arching at the top.

Flower

Yellow flowers 5–7 cm across with a yellow to brown centre, in panicles at the tops of the stems.

Flowering

From September into October, late in the season.

Roots

Creeping rhizomes: the clump widens slowly but does not run wild quickly.

Flowering: September–October · Plants: March–May · Pruning: February–March

Why grow it?

• Beautiful fine, willow-like foliage: the plant is ornamental long before it flowers.
• Flowers only in September and October, a sparse season in the border.
• A late nectar source for bees and butterflies; birds then eat the seeds.
• Tolerates drought better than most tall perennials, even on poor soil.
• Gives height and structure to the back of a sunny border.

Willow-leaved sunflower: where does it grow best?

• Full sun: in shade the stems get long and floppy and it hardly flowers.
• Ordinary garden soil: sand, loam or clay, acid to chalky. Well-drained soil is ideal.
• Dry to average moisture: it tolerates drought, but not permanently wet soil in winter.
• Sheltered from strong wind or staked, because the tall stems can blow over.
• Space plants 80–90 cm apart and put it at the back of the border.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Dry or normal

Size

2 m tall, 0.9 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Aster: Purple and blue autumn flowers contrast with the yellow.
• Ornamental grasses: Plumes and stems make an airy backdrop.
• Rudbeckia: Yellow and brown flowers in the same style, but lower.
• Sedum: A low, flowering foreground in pink and red in autumn.
• Japanese anemone: Pink or white flowers that go well with the late yellow.

Willow-leaved sunflower: when and how to plant it?

Plant in March–May.

1. Plant in March, April or May, once the soil is no longer frozen.
2. Dig a hole twice as wide as the root ball and mix in some compost if needed.
3. Set the plant at the same depth as in its pot and firm the soil well.
4. Leave 80–90 cm between plants.
5. Water thoroughly straight away and repeat in dry weather during the first year.
6. A layer of compost or fine bark around the base keeps weeds down.

Care

Water

In the first year, water thoroughly every week in dry weather. After that it is quite drought-tolerant and water in long dry spells is enough.

Feeding

Little or none: a spadeful of compost in spring is enough. Too much feed gives long, floppy stems.

Support

In windy spots, put in sturdy canes in May, or pinch the shoots in June.

Pinching

Cut the shoots back by a third at the end of May or in early June: lower, fuller plants with more branches.

Dividing

Dividing every three to four years keeps the clump vigorous and limits its spread.

Tip: Cut the shoots back by a third at the end of May: the plant stays lower, branches better and shows fewer bare lower stems. Put lower plants in front of it.

Willow-leaved sunflower: when to prune it?

Pruning months: February–March.

When: In late February or March, cut back the dead stems; optionally, cut the shoots back at the end of May.

How:

• Cut the old stems to 10–15 cm above the ground, before the new shoots appear.
• For a more compact plant, cut the shoots back by a third at the end of May. Flowering starts a little later, but the plant is more stable.
• Leave the seed heads standing in autumn for the birds and cut only in spring.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April, lift the clump and split it with a sharp spade into pieces with roots and shoots. Replant at once and water well.

Cuttings

In May–June, take cuttings of 10–15 cm from young shoots and put them in moist cutting compost. They root within a few weeks.

Willow-leaved sunflower: how does it get through the winter?

Hardy to −35 °C.

• Fully hardy to about −35 °C: no protection is needed in Belgian winters.
• The top growth dies back; leave the seed heads for the birds and cut back only in February or March.
• Make sure the soil drains well: wet feet in winter are more dangerous than frost.

Diseases and pests

• Slugs: Young shoots are eaten in spring. Pick off slugs, lay a barrier of crushed shells or set a slug trap.
• Powdery mildew: White powder on the leaves, especially in dry weather and dense planting. Water at the base, allow space and divide in good time.
• Bare lower stems: During summer the plant often drops its lower leaves. Plant lower plants in front or cut back in June.
• Flopping stems: In a windy or shady spot. Stake or pinch the shoots in June.

Through the year

• February: Cut old stems down to 10–15 cm above the ground.
• March: Divide and move. Apply compost.
• April: Plant. Watch for slugs on the young shoots.
• May: Plant. Optionally cut back by a third. Put in stakes.
• June: Water in dry weather. Support tall stems.
• July: Growth. Water now and then in dry weather.
• August: The leaves droop gracefully. Buds form.
• September: Flowering begins. Bees and butterflies visit the flowers.
• October: Full bloom. Leave seed heads for the birds.
• November: Dormant. Dead stems can stay standing.

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.

Did you know?

• Its narrow, drooping foliage gives it the look of a small willow, which is reflected in its name: salicifolius means willow-leaved.
• The plant grows naturally in the prairies of the United States, where it is used to dry, open grassland.
• In autumn its flowers are an important late food source for bees and butterflies.