How to grow Chrysanthemum

Chrysanthemum × morifolium · Chrysanthemum morifolium, garden mum, hardy mum

Autumn-flowering perennial with daisy-like, pompon or fully double flowers in many colours. Flower buds form as the days shorten, and garden mums bloom from late summer until hard frost. All parts are toxic to cats, dogs and horses.

Quick facts

Type	Flower
Family	Asteraceae
Light	Full sun
Soil pH	6–7
Frost	does not tolerate frost
Soil for sowing	from 8 °C
Where it grows	Greenhouse, Open ground, At home

When to plant

Sow straight into the bed after your last spring frost, once the soil has warmed.

In an unheated greenhouse everything moves about three weeks earlier.

Frost dates · When to plant

Care

Greenhouse

Stage	Watering	Temperature	Feeding
Growth	every 4 days	—	balanced (NPK), 28 days into the stage; balanced (NPK), 56 days into the stage
Flowering	every 4 days	—	—

Open ground

Stage	Watering	Temperature	Feeding
Growth	every 7 days	—	balanced (NPK), 28 days into the stage; balanced (NPK), 56 days into the stage
Flowering	every 7 days	—	—

At home

Stage	Watering	Temperature	Feeding
Growth	every 4 days	—	balanced (NPK), 28 days into the stage; balanced (NPK), 56 days into the stage
Flowering	every 4 days	—	—

Growing notes

Light

Full sun, at least 5–6 hours a day and ideally all day. In shade the plants sprawl and flower poorly.

Soil

Fertile, well-drained soil rich in organic matter, slightly acid to neutral (about pH 6.5). Avoid wet, shady spots, where diseases thrive.

Care

Plant rooted cuttings or young plants after the last frost, 45–60 cm apart. When they are about 15 cm tall pinch out the tips, and keep pinching every two weeks or so until early July; later pinching stops the flower buds forming. Water deeply in dry spells and never let the plants wilt; water early in the day so the leaves dry. Give a complete fertiliser about four weeks after planting and again a month later if growth is weak, then stop feeding once buds form. After a hard frost cut the stems to the ground and mulch; in cold areas lift the plants and keep them frost-free. Divide every 2 years. Watch for aphids, spider mites, leaf miners, powdery mildew and white rust.

Pests and diseases of Chrysanthemum

Sources

Figures checked against these sources.