Garden flowers

Chrysanthemum

ChrysanthemumAsteraceae
Also: Hardy chrysanthemum, Mum, Exhibition chrysanthemum
Hardy chrysanthemumMum

Hardy chrysanthemum

Mulch well in the first winter, especially on heavy soil, to help borderline-hardy types through frost.

Full sun Water: average H4down to −10 °C 60 cm–1 m tall · 45–60 cm wide In a pot: yes
Flowering · UK
Flowering · Northern Italy
Flowering · Central Italy
Flowering · Southern Italy and islands

Care

Light

Full sun.

Water

Standard border watering.

Soil

Fertile, well-drained soil.

Pruning

Cut back after flowering in late autumn; pinch out growing tips in late spring ('stopping') for bushier growth and more flowers.

Feeding

Feed every couple of weeks through summer with a balanced liquid feed, switching to high potash as the buds form. Stop once the flowers open — feeding late softens the plant just as autumn frosts arrive.

Propagation

Basal cuttings in spring from the shoots pushing up round the old stool: 5-8cm, cut below a node, in gritty compost somewhere bright and frost-free. Clumps can also simply be divided as growth starts.

Month by month

Months change with the climate: in southern Italy tomatoes go out two months earlier than in England.

  1. MayPinch out growing tips ('stopping') for bushier plants. how ›
  2. SeptemberMain flowering season — valuable late colour.
  3. NovemberCut back once flowering finishes. how ›

Months based on climate: UK. Your choice stays on this device.

  1. MayPinch out growing tips ('stopping') for bushier plants. how ›
  2. SeptemberMain flowering season — valuable late colour.
  3. NovemberCut back once flowering finishes. how ›

Months based on climate: Northern Italy. Your choice stays on this device.

  1. AprilPinch out growing tips ('stopping') for bushier plants. how ›
  2. SeptemberMain flowering season — valuable late colour.
  3. NovemberCut back once flowering finishes. how ›

Months based on climate: Central Italy. Your choice stays on this device.

  1. AprilPinch out growing tips ('stopping') for bushier plants. how ›
  2. SeptemberMain flowering season — valuable late colour.
  3. NovemberCut back once flowering finishes. how ›

Months based on climate: Southern Italy and islands. Your choice stays on this device.

Common problems

How to spot it. Clustered on new growth.

What to do. Encourage predators.

Powdery mildewfull sheet ›

How to spot it. White coating.

What to do. Improve airflow.

Slugs

How to spot it. On young growth.

What to do. Protect emerging shoots.

Exhibition chrysanthemum

Exhibition chrysanthemum

Plan overwintering space under cover from the start; this group is not garden-hardy.

Full sun Water: lots H2down to 1 °C 1–1.5 m tall · 45–60 cm wide In a pot: yes
Flowering · UK
Flowering · Northern Italy
Flowering · Central Italy
Flowering · Southern Italy and islands

Care

Light

Best grown under cover for exhibition-quality blooms.

Water

Standard container watering, heavier feeding.

Soil

Fertile, well-drained compost in pots, fed heavily through the season.

Pruning

Pinch out growing tips ('stopping') and disbud side shoots for larger show blooms, if wanted.

Feeding

Fed harder than the border types, because the flowers are the point: a balanced liquid feed through the growing season, switching firmly to high potash once the buds are set. Too much nitrogen late gives soft stems and split blooms.

Propagation

Basal cuttings in late winter from stools lifted and boxed up under cover after flowering. This is how named exhibition varieties are kept going year to year — they are not plants to leave outside over winter in the hope they return.

Month by month

Months change with the climate: in southern Italy tomatoes go out two months earlier than in England.

  1. MayStop (pinch out) growing tips for bushier growth. how ›
  2. AugustFeed heavily as flower buds develop. how ›
  3. OctoberMove under cover before frost — this group will not survive outside over winter. how ›

Months based on climate: UK. Your choice stays on this device.

  1. MayStop (pinch out) growing tips for bushier growth. how ›
  2. AugustFeed heavily as flower buds develop. how ›
  3. OctoberMove under cover before frost — this group will not survive outside over winter. how ›

Months based on climate: Northern Italy. Your choice stays on this device.

  1. AprilStop (pinch out) growing tips for bushier growth. how ›
  2. AugustFeed heavily as flower buds develop. how ›
  3. NovemberMove under cover before frost — this group will not survive outside over winter. how ›

Months based on climate: Central Italy. Your choice stays on this device.

  1. AprilStop (pinch out) growing tips for bushier growth. how ›
  2. AugustFeed heavily as flower buds develop. how ›
  3. NovemberMove under cover before frost — this group will not survive outside over winter. how ›

Months based on climate: Southern Italy and islands. Your choice stays on this device.

Common problems

How to spot it. Clustered on new growth.

What to do. Encourage predators.

Powdery mildewfull sheet ›

How to spot it. White coating.

What to do. Improve airflow.

Frost death

How to spot it. If left outside over winter.

What to do. Must overwinter under cover — the key difference from hardy border types.

Popular varieties

Chrysanthemum ‘Clara Curtis’75 cm × 60 cm · August–OctoberAugust–OctoberAugust–OctoberAugust–October · Hardy chrysanthemum

Questions

Chrysanthemum: is it hardy?

Hardy chrysanthemum: H4: Hardy through an average UK winter. It survives down to −10 °C. Exhibition chrysanthemum: H2: Tender. It survives down to 1 °C.

Can it grow in a pot?

Hardy chrysanthemum: Standard container culture. Exhibition chrysanthemum: Typically grown in pots for ease of moving under cover.

Chrysanthemum: when do you prune it?

Hardy chrysanthemum: Cut back after flowering in late autumn; pinch out growing tips in late spring ('stopping') for bushier growth and more flowers. In the calendar for UK, pruning falls in November. Exhibition chrysanthemum: Pinch out growing tips ('stopping') and disbud side shoots for larger show blooms, if wanted.

Chrysanthemum: when does it flower?

Hardy chrysanthemum: In the climate of UK it flowers in September–November. Exhibition chrysanthemum: In the climate of UK it flowers in October–November.

When do you feed it?

Hardy chrysanthemum: Feed every couple of weeks through summer with a balanced liquid feed, switching to high potash as the buds form. Stop once the flowers open — feeding late softens the plant just as autumn frosts arrive. Feeding months, UK: May–July. Exhibition chrysanthemum: Fed harder than the border types, because the flowers are the point: a balanced liquid feed through the growing season, switching firmly to high potash once the buds are set. Too much nitrogen late gives soft stems and split blooms. Feeding months, UK: May–August.