Helianthus annuus 'Russian Giant'

RHS Plant Profile
sunflower 'Russian Giant'
Plants for pollinators
Annual Biennial

A tall and large, fast-growing annual with oval to heart-shaped, roughly hairy green leaves. In summer, they produce wonderfully large sunny yellow flower with a chocolate brown centre up to 30cm (12in) across . Great for seeing who can grow the tallest and for attracting bees, the seeds that follow provide food for finches

Position

Full sun

Soil Types

Chalk, Clay, Loam, Sand

Max Height

2.5-4 metres

Max Spread

0.5-1 metres

Size

Time to Maturity
1 year
Max Spread
0.5-1 metres
Max Height
2.5-4 metres

Growing Conditions

Chalk Clay Loam Sand
Moisture
Moist but well–drained
pH
Neutral or Alkaline

Position

Full sun
Aspect
South–facing or West–facing
Exposure
Sheltered
Hardiness
H4

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Asteraceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Columnar upright
Genus
Helianthus can be tall, erect annuals, tuberous or rhizomatous perennials, with coarse simple leaves and large daisy-like flower-heads
Name Status
Unresolved

How to Grow

Cultivation

Grow in a moderately fertile, humus-rich, moist but well-drained, neutral to alkaline soil in full sun. Will flower best in a long, hot summer. May need a cane to support the weight of the bloom and grow tall

Propagation

Propagate by seed or division. Divide established clumps every 2-4 years to both increase plants and retain vigour. See sowing seeds indoors for further advice

Suggested planting locations and garden types

  • Wildlife gardens
  • Cottage and informal garden
  • Flower borders and beds
  • Cut flowers
  • Wall side borders

Pruning

Cut back old stems after flowering as they die down for the winter

Pests

May be susceptible to slugs and snails

Diseases

May be susceptible to Powdery mildews and sclerotinia diseases