Prairie Sun black-eyed Susan

Sun

Full sun; light afternoon shade is useful in very hot climates, but too much shade reduces flowering.

Water

Water regularly while establishing, then when the upper soil dries. Established plants tolerate brief dry spells, but flower better with steady moisture; containers need more frequent watering.

Soil

Well-drained soil with average fertility; tolerates clay if it does not remain waterlogged. Avoid heavily enriched, soggy ground.

Height

2-3 ft (0.6-0.9 m)

Spread

1-2 ft (0.3-0.6 m)

Flowers

Summer to autumn, often until frost; golden-yellow petals with pale yellow tips surround a green cone that darkens with age.

Foliage

Rough, hairy, green leaves, with broader leaves near the base and smaller leaves along the upright stems.

Growth

Fast; flowers in its first growing season from an early sowing.

Care needed

Low

• Pollinators
• Heat tolerant
• Wildlife

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.5 ft (0.15 m)

2. After 1 year

   2.5 ft (0.75 m)

   full size

Full size in one season.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Native to

the US and Canada

Growth rate

Fast

• Plant out after frost danger has passed, spacing plants about 12-18 in (30-45 cm) apart.
• Water at soil level when the upper soil dries; avoid keeping the crown wet.
• Mix a little compost into poor soil before planting; avoid heavy nitrogen feeding, which encourages floppy growth.
• Apply a thin mulch to conserve moisture, keeping it clear of the stems.
• Support exposed plants with discreet stakes or a low ring before stems lean.

Pruning. Remove faded flowers back to a leaf or side shoot to encourage more blooms. In autumn, leave some seedheads for birds or remove the plants once they have died; clear diseased foliage rather than leaving it over winter.

Late winter

Sow seeds indoors about 8-10 weeks before the last expected frost; press onto moist seed compost and barely cover.

Spring

Gradually harden off seedlings before planting outside.

Late spring

Plant after frost danger has passed, water thoroughly and add supports in windy sites.

Summer

Water during dry spells and remove faded flowers regularly.

Early autumn

Leave selected flowerheads to form seed for birds.

Late autumn

Remove dead plants when seedheads are spent, and dispose of any diseased foliage.

• Plant in repeated groups through a sunny mixed border for a long season of yellow flowers.
• Combine with purple salvias and blue catmint for strong colour contrast.
• Mix with airy ornamental grasses for a loose, prairie-style summer display.
• Grow in large containers with good drainage as a tall seasonal focal point.
• Include in a cutting garden for sturdy, long-stemmed flowers.

Garden styles it suits: Cottage garden, Pollinator garden, New perennial (prairie), Farmhouse, Hot border and Midwest prairie.

Plant it with: Purple coneflower, Meadow sage, Catmint, Switchgrass, Tall verbena and Zinnia.

Wildlife: The flowers provide pollen and nectar for bees and other visiting insects. Mature seedheads can feed seed-eating birds; leave some standing into the cooler months.

• Powdery mildew: improve spacing and airflow, water at soil level and remove badly affected foliage.
• Leaf spot: avoid overhead watering, remove infected leaves and clear affected debris at the end of the season.
• Slugs and snails: protect young plants, remove hiding places nearby and use wildlife-conscious slug controls where needed.
• Flopping or poor flowering: move future plantings into full sun, reduce nitrogen feeding and support stems in exposed positions.

Not known to be toxic to cats, dogs, horses or people. It is not a food plant; eating plant material may cause mild stomach upset, and the rough hairs can irritate sensitive skin.

• Irish Eyes black-eyed Susan (Rudbeckia hirta 'Irish Eyes')

  Also has a green centre, but its petals are generally a more uniform golden yellow rather than showing Prairie Sun's distinct pale yellow tips.

• Goldsturm black-eyed Susan (Rudbeckia fulgida var. sullivantii 'Goldsturm')

  Has a dark brown central cone and more uniformly golden petals; it is also a dependable clump-forming perennial rather than mainly a seasonal bedding plant.

Rudbeckia honours the Swedish botanists Olof Rudbeck the Elder and Younger, while hirta means hairy, referring to the rough hairs on the leaves and stems.

Propagation. Grow from seed, preferably bought seed labelled 'Prairie Sun' for a consistent display. Sow indoors before the last frost or directly into warm soil after frost danger has passed; direct-sown plants flower later. Saved seed and self-sown seedlings may differ from the parent.

Accepted botanical name

Rudbeckia hirta

In the US and Canada

Native in Canada and the lower 48 states. Introduced in Alaska.

Native range

Alabama, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Idaho, Illinois and Indiana.

Measured

Soil pH 6 to 7. Average height 58 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.