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Silphium trifoliatum (Whorled rosinweed)

Beginner
skill rating
1 hour care
per year
2m
Max height
1m
Max spread
2-5 years
To maturity

Plant details

Botanical name

Silphium trifoliatum

Other names

Whorled rosinweed, Silphium asteriscus var. trifoliatum, Three-leaved rosinweed

Genus

Silphium Silphium

Species

S. trifoliatum - S. trifoliatum is an upright, clump-forming, herbaceous perennial with whorled, narrowly elliptic, rough, toothed, grey-green leaves and branched clusters of yellow flower heads from midsummer to early autumn.


Silphium trifoliatum is: Deciduous

Habit

Clump-forming, Erect

Flower

Yellow in Summer; Yellow in Autumn

Foliage

Mid-green in Spring; Mid-green in Summer; Mid-green in Autumn

How to care

Watch out for

Pests

Generally pest free.

Diseases

Generally disease free.

General care

Pruning

Cut back after flowering. Alternatively, cut back in early spring before new growth emerges. May need staking in windy sites.

Propagation methods

Division, Seed


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Where to grow

Silphium trifoliatum (Whorled rosinweed) will reach a height of 2m and a spread of 1m after 2-5 years.

Suggested uses

Woodland, Wildlife, Wildflower, Cottage/Informal, Beds and borders, Architectural

Cultivation

Grow in moist, deep, moderately fertile, neutral to alkaline soil in sun or partial shade. Performs best in heavy clay.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Alkaline, Neutral

Light

Partial Shade, Full Sun

Aspect

South, East, West

Exposure

Exposed, Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

Companion plants

This plant can hold its own against big bold plants such as hostas and acanthus.

We do not currently have companion plants added for this plant.

Botanical name

Silphium trifoliatum

Other names

Whorled rosinweed, Silphium asteriscus var. trifoliatum, Three-leaved rosinweed

Genus

Silphium Silphium

Species

S. trifoliatum - S. trifoliatum is an upright, clump-forming, herbaceous perennial with whorled, narrowly elliptic, rough, toothed, grey-green leaves and branched clusters of yellow flower heads from midsummer to early autumn.

Foliage

Deciduous

Habit

Clump-forming, Erect


Colour

Flower

Yellow in Summer; Yellow in Autumn

Foliage

Mid-green in Spring; Mid-green in Summer; Mid-green in Autumn


How to care

Watch out for

Pests

Generally pest free.

Diseases

Generally disease free.

General care

Pruning

Cut back after flowering. Alternatively, cut back in early spring before new growth emerges. May need staking in windy sites.

Propagation methods

Division, Seed


Monthly care advice


Where to grow

Silphium trifoliatum (Whorled rosinweed) will reach a height of 2m and a spread of 1m after 2-5 years.

Suggested uses

Woodland, Wildlife, Wildflower, Cottage/Informal, Beds and borders, Architectural

Cultivation

Grow in moist, deep, moderately fertile, neutral to alkaline soil in sun or partial shade. Performs best in heavy clay.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Alkaline, Neutral

Light

Partial Shade, Full Sun

Aspect

South, East, West

Exposure

Exposed, Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

USDA zones

Zone 9, Zone 8, Zone 7, Zone 6, Zone 5, Zone 4, Zone 3

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This plant likes... Garden match
Soil types: Chalky, Clay, Loamy, Sandy (will tolerate most soil types) Tell us...
Soil drainage: Moist but well-drained, Well-drained Tell us...
Soil pH: Alkaline, Neutral Tell us...
Light: Partial Shade, Full Sun Tell us...
Aspect: South, East, West Tell us...
Exposure: Exposed, Sheltered Tell us...
Hardiness: Hardy (H4) Tell us...

COMPANION PLANTS

This plant can hold its own against big bold plants such as hostas and acanthus.

We do not currently have companion plants added for this plant.

GARDENS WITH THIS PLANT

My Garden
My Garden
elizabeth bradbury

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