Chrysanthemum parthenium 'Plenum' (Feverfew Double) — Bushy, upright

Overview

Chrysanthemum parthenium 'Plenum' is a bushy, upright perennial in the genus Chrysanthemum, part of the Asteraceae family, with deciduous; lobed, aromatic, mid to grey-green foliage. Chrysanthemum parthenium 'Plenum' grows best in full sun, and tolerates fertile and well-manured loam soils and neutral to slightly acid pH. Its UK hardiness is rated H2–H5 depending on group. Suggested uses include ornamental, borders and cut flowers. It is native to Europe.

About

Chrysanthemum parthenium 'Plenum' is a perennial feverfew cultivar that forms a well-branched, upright plant and carries double flower heads. It has deciduous, lobed foliage that is mid to grey-green and aromatic with a mild, slightly bitter scent. Flowering occurs from August to October. The foliage and sap are mildly toxic and may cause skin irritation, so handle with care.

Wikipedia contributors, CC BY-SA 4.0 — Tanacetum parthenium

About the genus

Chrysanthemums, sometimes abbreviated to mums or chrysanths, are perennial herbaceous flowering plants in the family Asteraceae that bloom in the autumn. They are native to East Asia and northeastern Europe. Most species originate from East Asia, and the center of diversity is in China.

Wikipedia contributors, "Chrysanthemum", CC BY-SA 4.0 — Chrysanthemum

In the garden

Native to Europe, Chrysanthemum parthenium 'Plenum' is a cultivated form of feverfew grown for its double-flowered habit and use in borders and as a cut flower. It prefers a south- or west-facing, sheltered site in the garden where it receives full sun and benefits from rich, well-manured loam. Neutral to slightly acid soil suits it best, and the soil should remain moist but well drained. Winter tolerance varies with stock, rated H2–H5 in the UK, which means plants range from half-hardy to fully hardy depending on provenance; the equivalent USDA range is 5–9. Position plants where they are protected from cold winds and avoid waterlogged ground over winter. Give the soil a deep dressing of organic matter before planting to establish quickly in fertile ground. Use 'Plenum' towards the front or middle of herbaceous borders and harvest stems in August–October for indoor arranging. Note the foliage’s mild, bitter aroma when crushed, and take precautions when cutting or deadheading: the plant is mildly toxic if ingested and can irritate skin, so wear gloves if handling stems for extended periods.

Growing conditions

Best soil and position for Chrysanthemum

Sunlight: Full sun
Soil type: Fertile, well-manured loam
Soil pH: Neutral to slightly acid
Soil moisture: Moist but well drained
Aspect: South or west facing
Exposure: Sheltered
UK hardiness: H2–H5 depending on group

Plant details

Chrysanthemum parthenium 'Plenum' size, habit and characteristics

Plant type: Perennial
Habit: Bushy, upright
Foliage: Deciduous; lobed, aromatic, mid to grey-green
Suggested uses: Ornamental, Borders, Cut flowers
Native to: Europe
Fragrance: Mild, slightly bitter
Toxicity: Mildly toxic if ingested, may cause skin irritation

Care notes

Pruning and caring for Chrysanthemum parthenium 'Plenum'

Cultivation: These are hungry plants: feed and water generously right through the growing season. Stop the growing tips in early summer to build a branching, well-furnished plant, stake before the flower weight arrives, and lift tender or exhibition kinds after flowering to overwinter the stools in a frost-free frame.
Pruning: Pinch out growing tips in late spring and early summer to encourage branching. Cut stems down to about 15cm after flowering, then lift for storage where the cultivar is not reliably hardy.
Propagation: Take basal cuttings from overwintered stools in late winter and early spring. Hardy border kinds can also be divided in spring.
Pest resistance: Aphids, leaf miner, capsid bug and earwigs all favour the soft growth; eelworm affects long-established stools.
Disease resistance: Susceptible to white rust and powdery mildew under glass or in crowded plantings, so ventilation is essential.

Frequently asked questions

How do I grow Chrysanthemum parthenium 'Plenum'?

These are hungry plants: feed and water generously right through the growing season. Stop the growing tips in early summer to build a branching, well-furnished plant, stake before the flower weight arrives, and lift tender or exhibition kinds after flowering to overwinter the stools in a frost-free frame.

Where is the best place to plant Chrysanthemum parthenium 'Plenum'?

Chrysanthemum parthenium 'Plenum' prefers full sun. It suits sheltered positions.

What soil does Chrysanthemum parthenium 'Plenum' need?

Chrysanthemum parthenium 'Plenum' grows best in fertile and well-manured loam soil. It prefers neutral to slightly acid soil. Aim for soil that stays moist but well drained.

How do I prune Chrysanthemum parthenium 'Plenum'?

Pinch out growing tips in late spring and early summer to encourage branching. Cut stems down to about 15cm after flowering, then lift for storage where the cultivar is not reliably hardy.

Is Chrysanthemum parthenium 'Plenum' hardy in the UK?

Chrysanthemum parthenium 'Plenum' has an RHS hardiness rating of H2, meaning it is tender, tolerating 1–5°C, and needs frost-free protection over winter.

How do I propagate Chrysanthemum parthenium 'Plenum'?

Take basal cuttings from overwintered stools in late winter and early spring. Hardy border kinds can also be divided in spring.

Is Chrysanthemum parthenium 'Plenum' toxic?

Mildly toxic if ingested, may cause skin irritation.

More in the Chrysanthemum genus

Browse all Chrysanthemum →