Black-eyed Susan

Black-eyed Susan: how do you recognise it?

Habit

Upright, branching plant about 60 cm tall and 40 cm wide.

Leaves

Oblong to oval, roughly hairy, like the stems.

Flowers

Daisy-like heads of 5–10 cm with yellow, orange or red-brown ray petals around a domed, dark brown to black centre.

Flowering

From July to October, as long as you remove spent flowers.

Seed

In autumn the dark centre ripens into a seed head full of small seeds.

Flowering: July–October · Sowing: March–May · Plants: May–June

Why grow it?

• Flowers from July into October, when many other flowers are past their best.
• A sturdy cut flower that lasts well in the vase.
• Bees and butterflies find nectar and pollen easily on the open flowers.
• Quick results: it flowers fully in the first summer after sowing.
• Warm colours from golden yellow to mahogany red, lovely in a sunny border or in pots.

Black-eyed Susan: where does it grow best?

• Full sun: that is where it flowers best and the stems stay sturdy.
• Ordinary, well-drained garden soil: sand, loam or clay, acid to chalky.
• Moist soil; water during prolonged drought.
• Space 30–40 cm apart, or 25 cm in a pot or container.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.6 m tall, 0.4 m wide

Hardiness

Hardy (to -15 °C)

Goes well with

• Ornamental grasses: Their airy plumes lighten the sturdy flowers.
• Tall verbena: Small purple heads on tall stems that weave between the rudbeckias.
• Cosmos: Another easy annual that flowers into autumn.
• Purple coneflower: A pink relative that wants the same sun and soil.
• Sunflower: A cheerful, tall backdrop in the same warm colours.

Black-eyed Susan: when and how to plant it?

Plant in May–June.

1. Sow indoors in March–April in seed compost at 18–20 °C; barely cover the seed. It germinates in one to three weeks.
2. Prick out the seedlings into small pots once they have two true leaves.
3. In May, harden the plants off for a week: outside by day, indoors at night.
4. Plant out in May–June, after the last night frost, 30–40 cm apart. Sowing direct outdoors is possible in May.
5. Work some compost into the soil when planting and water in well.
6. Protect the young plants from slugs for the first few weeks.

Care

Watering

In dry spells, especially in the first weeks after planting out and in pots. Water at the base, not over the leaves.

Feeding

Compost at planting time is enough. In pots, a liquid feed for flowering plants every two weeks.

Deadheading

Remove spent flowers regularly, back to a leaf or side bud: it will then flower until October.

Support

In a windy spot or for tall varieties, add a cane or a few twigs.

Cutting

Cut flowers just as they open, in the morning, and put them straight into water.

Tip: Sow indoors in March–April and then deadhead faithfully: it will flower freely in its very first summer, right into October.

Black-eyed Susan: when to prune it?

When: No real pruning needed. From July to October, simply remove spent flowers.

How:

• Cut spent flowers back to the first leaf or side bud.
• In September, let a few good flowers go to seed if you want to collect seed.
• Clear the plants in late autumn, or leave a few seed heads for some winter structure.

Pruning calendar and basic rules

Propagation

Sowing indoors

In March–April in seed compost at 18–20 °C, seed barely covered. Prick out and plant out from May.

Sowing outdoors

In May where it is to flower, in a fine, moist seedbed; thin later to 30–40 cm. It will then flower a little later.

Saving seed

In autumn let a few flowers go to seed and dry the seed heads. Varieties do not always come true from saved seed.

Black-eyed Susan: how does it get through the winter?

Hardy to −15 °C: protect young plants.

• It tolerates some frost but is often short-lived: grow it as an annual and sow again every year.
• On well-drained soil a plant sometimes survives a mild winter and flowers a second year; do not count on it.
• If you leave a few seed heads, it sometimes self-seeds.

Diseases and pests

• Slugs: They can strip young plants overnight. Pick them off in the evening and only plant out sturdy plants.
• Damping off: Seedlings collapse at the base and fall over: a fungus encouraged by wet, warm conditions. Sow thinly, water from below and give fresh air.
• Powdery mildew: White powder on the leaves in late summer, especially in dry weather. Water at the base, space plants well and cut off affected leaves.
• Aphids: On young shoots and buds. Blast them off with a strong jet of water; ladybirds help too.

Through the year

• March: Sow indoors at 18–20 °C.
• April: Sow indoors. Prick out seedlings.
• May: Harden off and plant out after the last frost. Sow outdoors.
• June: Plant out. Protect young plants from slugs.
• July: Flowering begins. Remove spent flowers.
• August: Full bloom. Water in dry spells. Cut flowers for the house.
• September: Flowering. Let a few flowers go to seed.
• October: Last flowers. Collect seed.
• November: Clear the plants or leave the seed heads standing.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• Black-eyed Susan has been the state flower of Maryland in the United States since 1918.
• Linnaeus named the genus after Olof Rudbeck, father and son, two Swedish scholars from Uppsala.
• Hirta is Latin for ‘roughly hairy’: just feel the stems and leaves.