Silphium laciniatum

RHS Plant Profile
compass plant

Other common names

gopher plant, pilot plant, pilot weed, polar plant, ragged cup, rosin weed

Herbaceous Perennial

A large upright perennial, to 3m tall, with hairy, aromatic, fern-like leaves, to 50cm long, becoming smaller up the stems. In late summer and early autumn it bears narrow sprays of bright yellow daisies, each up to 12cm across

Position

Full sun, Partial shade

Soil Types

Clay, Loam

Max Height

2.5-4 metres

Max Spread

0.5-1 metres

Size

Time to Maturity
2–5 years
Max Spread
0.5-1 metres
Max Height
2.5-4 metres

Growing Conditions

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

Position

Full sun Partial shade
Aspect
South–facing or West–facing
Exposure
Exposed or Sheltered
Hardiness
H7

Colour & Scent

Fragrance Foliage
Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Asteraceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Columnar upright
Genus
Silphium are robust herbaceous perennials with tall stems bearing simple leaves, aromatic when bruised, and loose clusters of yellow, daisy-like flowers in summer and early autumn
Name Status
Correct
Plant Range
E North America

How to Grow

Cultivation

Grow in moderately fertile, moist, deep, neutral to slightly alkaline, heavy soil in full sun or partial shade

Propagation

Propagate by seed or division

Suggested planting locations and garden types

  • Wildlife gardens
  • Architectural
  • Cottage and informal garden
  • Flower borders and beds

Pruning

Cut back after flowering; stems may optionally be left until shortly before new growth begins the following season

Pests

Generally pest-free

Diseases

Generally disease-free