Florist’s chrysanthemum

Florist’s chrysanthemum: how do you recognise it?

Habit

Bushy, clump-forming plant 40–90 cm high and about 60 cm wide; branches well if you pinch out the tips.

Leaves

Deeply lobed, grey-green to dark green, with a spicy smell when crushed.

Flower

Flower heads 3–10 cm across or more: single, semi-double, double, pompon or with tubular ‘spider’ petals.

Colour

White, yellow, orange, bronze, pink, red and purple, often in warm autumn shades.

Flowering time

September to November. It is a short-day plant: it only flowers once the days get shorter.

Roots

Shallow, with short underground runners from which new shoots appear.

Flowering: September–November · Plants: April–May and September · Pruning: March and May–June

Why grow it?

• Colour in the border when most perennials have finished, until the first hard frost.
• A late source of pollen and nectar for bees and hoverflies, especially the single-flowered cultivars.
• A classic cut flower that lasts two weeks or more in a vase.
• A huge choice of colours and flower shapes, from small pompons to large, single, daisy-like blooms.
• Easy to propagate by division or cuttings.

Florist’s chrysanthemum: where does it grow best?

• Full sun and a warm spot: the more light, the sturdier the plant and the better it flowers.
• Any free-draining garden soil: sand, loam or clay, acid to chalky, ideally rich in humus.
• Normally moist in summer, but never waterlogged in winter; on heavy soil, plant in a slightly raised bed.
• Sheltered from strong wind, so the flowering stems do not flop.
• Plant 45–60 cm apart, so air can move between the plants.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.6 m tall, 0.6 m wide

Hardiness

Hardy (to -15 °C)

Goes well with

• Michaelmas daisy: Flowers at the same time, in blue and purple beside the warm chrysanthemum shades.
• Showy stonecrop: Broad pink flower heads and fleshy leaves in the same sunny spot.
• Ornamental grasses: Fountain grass and miscanthus add movement and an autumnal backdrop.
• Dahlia: Also flowers until the first frost.
• Coneflower: Its seed heads stand nicely beside the late chrysanthemum flowers.

Florist’s chrysanthemum: when and how to plant it?

Plant in April–May and September.

1. Plant garden chrysanthemums preferably in April–May, so they are well rooted before winter. September is possible too, but they then survive the winter less often.
2. Dig a hole twice as wide as the root ball and mix in compost and, on heavy soil, some coarse sand.
3. Set the plant at the same depth as in the pot and firm the soil well.
4. Allow 45–60 cm between plants.
5. Water well straight away, and again in dry spells during the first few weeks.
6. A thin layer of compost as mulch keeps the soil moist in summer; keep it clear of the base of the plant.

Care

Water

Regularly in dry summer weather, at the base and not over the leaves. Keep it dry in winter.

Feeding

Organic fertiliser or compost in May and June; no more feeding after August.

Pinching

Until the end of June, pinch out the tips of the young shoots: the plant becomes fuller and sturdier and flowers more.

Support

Stake tall cultivars in June with canes or a plant support.

Deadheading

Remove spent flowers for a tidy plant and a longer display.

Division

Every 2–3 years in spring: the centre of old clumps becomes bare and weak.

Tip: Pinch out the tips of the young shoots until the end of June: you get a compact, sturdy plant covered in flowers from top to bottom.

Florist’s chrysanthemum: when to prune it?

Pruning months: March and May–June.

When: Only cut back the old stems in March, and pinch out the tips in May–June.

How:

• Leave the spent stems over winter: they protect the heart of the plant from cold and wet.
• In March, when new shoots appear at the base, cut all old stems back to 5–10 cm above the ground.
• In May and June, pinch out the tips of the young shoots just above a leaf. Stop at the end of June, or it will flower too late.
• Remove spent flowers in autumn.

Caution: Do not prune in autumn: a plant that goes into winter with its old stems survives better.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In April: lift the clump, keep the young, healthy pieces from the edge with their own roots and discard the old centre.

Cuttings

In March–April: 5–8 cm cuttings from the young shoots at the base, lower leaves removed, in moist cutting compost under plastic. They root in 2–3 weeks.

Florist’s chrysanthemum: how does it get through the winter?

Hardy to −15 °C: protect young plants.

• Garden chrysanthemums are hardy to about −15 °C, but only in free-draining soil: wet soil is the main cause of death.
• Leave the old stems standing and, in severe winters, cover the base with a layer of dry leaves or conifer branches.
• Pot chrysanthemums from the shop are often less hardy. After flowering, keep them cool and frost-free and plant them out in spring.
• In a pot: keep it sheltered against a wall, under an overhang, and give hardly any water in winter.

Diseases and pests

• Winter losses: The plant does not return in spring, usually because of wet soil. Plant in spring, improve drainage and only cut back in March.
• Aphids: On shoot tips and flower buds in spring and summer. Spray off with water; ladybirds and parasitic wasps help.
• Powdery mildew: White powder on the leaves in dry weather and poor air flow. Space plants more widely, water at the base and remove affected leaves.
• Earwigs: Holes in the petals in late summer. In the evening hang an upturned flowerpot stuffed with straw on a cane, and in the morning move the earwigs to a fruit tree, where they eat aphids.
• White rust: Pale spots on the upper side and white to buff pustules on the underside of the leaves. Remove affected plants and put them in the household waste, not on the compost.

Through the year

• March: Cut old stems back to 5–10 cm. Take cuttings.
• April: Plant. Divide. Take cuttings.
• May: Plant. Pinch out tips. Feed.
• June: Pinch out tips until the end of June. Stake tall cultivars.
• July: Water in dry weather. Watch for aphids.
• August: Water in dry weather. Stop feeding.
• September: Flowering begins. Planting is still possible, preferably early in the month.
• October: Full flower. Cut flowers for the vase.
• November: Last flowers. Remove spent blooms, leave the stems.
• December: Rest. Keep the base dry; in hard frost cover with dry leaves.

Edible and useful

Not edible. Chrysanthemums are poisonous to cats, dogs and horses: chewing the leaves and flowers causes drooling, vomiting and diarrhoea, and the sap can cause a rash in sensitive people. In China a tea is made from the dried flowers of special varieties, but do not use chrysanthemums from the garden or the florist: they are not grown for it and are often sprayed. Do not let children eat the flowers or leaves, keep a pot or vase of chrysanthemums out of reach of cats, and wear gloves when pruning and taking cuttings. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• In Japan the chrysanthemum is the emblem of the imperial house; the imperial throne is called the Chrysanthemum Throne.
• In Belgium and France chrysanthemums are traditionally placed on graves around All Saints’ Day, on 1 November.
• As a short-day plant it can be steered: growers make pot chrysanthemums flower all year by controlling day length with lamps and blackout screens.