Silphium mohrii

Genus: Silphium

Species: mohrii

Family Name: Compositae/Asteraceae

Seed Catalogue No.: 1175F

English Name(s): Shaggy Rosinweed

Hardiness: Hardy

Lifecycle: Perennial

Colour: Yellow/Orange

Flowers: July, August, September, October, November

Lighting Conditions: Full Sun

Soil Type: Clay, Chalk, Sand, Loam

Soil Acidity: Alkaline, Neutral, Acid

Moisture: Well-drained

Germination Instructions

Sow in a cold frame in autumn. Can be sown directly in spring with prior cold stratification. In a cold frame, surface sow onto moist, well-drained seed compost. Just cover seed with a sprinkling of soil. Allow natural winter cold to offer ideal conditions for germination to occur in spring as the weather warms. For spring sowing, mix seed with damp soil and place in a zip-lock style freezer bag and cold stratify at 4°C, a fridge is ideal, for 6-8 weeks. The seeds can then be sown directly where spring warmth should offer germination in 2-3 weeks. Transplant seedlings when large enough to handle to final growing position, before the long tap root forms.

Growing Instructions

Prefers any ordinary, well-drained soil in full sun. Will tolerate poor soils. This plant may require staking. This plant may take several years to flower from seed. A tall, sturdy, rough plant on resinous stems. Split or broken stems will exude a gummy, bitter resin which was used by native Americans as chewing gum.

Cultivation Instructions

Propagate by seed. Deep tap roots make propagation by division difficult.

When to Sow

• Sow Under Cover/Plant Indoors
• Direct Sow/Plant Outdoors
• Flowers/Harvest

Approximate number of seeds per packet: 10

Please note we pack the majority of our seeds by volume so the number of seeds indicated is only an approximation.