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Silphium mohrii

shaggy rosinweed

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Bright, buttery-yellow daisy flowers bring a cheerful splash of colour to the garden, held on sturdy, branching stems that create a bold, upright presence from midsummer onwards. Silphium mohrii is a superb choice for prairie-style planting and naturalistic borders, where it combines beautifully with ornamental grasses and late-flowering asters in shades of blue and purple

Its long flowering season provides a valuable source of nectar for bees, butterflies and other pollinating insects, while the robust habit copes well with dry spells once established. Also tolerant of coastal conditions and generally avoided by deer and rabbits, this reliable perennial is an easy-care option for adding height, movement and wildlife interest to sunny planting schemes.

How to care for Silphium mohrii:

Plant shaggy rosinweed in a sunny position in fertile, well-drained soil, allowing enough space for its upright habit to develop. Water regularly during the first growing season to help it establish, after which it becomes impressively drought tolerant.

Deadhead faded blooms to encourage a longer flowering display, or leave the seed heads in place to provide autumn and winter interest for wildlife. Cut the stems back to ground level in late winter or early spring before new growth emerges, and avoid moving established plants unnecessarily, as their deep root system prefers to remain undisturbed.
Flowering period:
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
Eventual height:
1.5m
Eventual spread:
0.6m
Position:

Light shade / shade

Rate of growth:

Average

Soil:

Moderately fertile, moist, well-drained soil

Hardiness:

Fully hardy

  • InformationThis perennial dies back to below ground level each year in autumn, then fresh new growth appears again in spring.

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