Chrysanthemum
Chrysanthemum × morifolium · also called Guldaudi, mum
Flowering
- Light
- Sunny, Part sun
- Pot size
- Medium pot (about 5 to 15 litres)
- Care level
- Moderate
- Year round or seasonal
- Kept year to year; cold-hardy in the ground to about −28.9 °C (−20 °F)
- Pets
- ASPCA: toxic to pets
Light and position
Full sun, with protection from afternoon sun in warm places; too much shade makes plants sprawl.
Size and pot
NC State lists 1 to 3 feet. Our pot band: medium pot (about 5 to 15 litres).
Watering
Keep the soil moist but well drained.
Potting mix and feeding
Soil high in organic matter.
Growing through the year
Flowers in autumn. NC State suggests cutting stems back a few times during the growing season to keep plants bushy.
Winter outdoors
Cold-hardy in the ground to about −28.9 °C (−20 °F). NC State lists USDA zones 5a to 9b. The lower edge of zone 5a, −20 °F, describes plants in the ground; NC State notes that roots in a container are less insulated from cold, so we do not rate a pot below −5 °C.
| Your coldest winter nights | What to do |
|---|---|
| Coldest nights 15 °C or warmer | Can stay out through this winter |
| Coldest nights 10 to 15 °C | Can stay out through this winter |
| Coldest nights 5 to 10 °C | Can stay out through this winter |
| Coldest nights 0 to 5 °C | Can stay out; wrap the pot or move it to a sheltered spot in freezing weather |
| Light frost: nights down to about −5 °C | Can stay out; wrap the pot or move it to a sheltered spot in freezing weather |
| Hard frost: nights below −5 °C | Shelter it or insulate the pot: we do not rate any potted plant for nights below −5 °C |
A plant can stay out only when its limit is below the coldest night in your band; a limit equal to that night counts as needing shelter. A rare cold snap, wind or a wet pot can still damage plants. USDA describes hardiness zones as general guides based on average yearly lowest temperatures, and they describe plants in the ground. NC State warns that roots in a container are not as well insulated from cold as roots in the ground, and suggests wrapping pots or moving them to a sheltered spot. We convert °F to °C with NIST’s formula.
Watch for
Aphids, thrips and spider mites; powdery mildew, rust and root rot.
Pets and people
ASPCA lists chrysanthemum as toxic to dogs, cats and horses (sesquiterpene lactones, pyrethrins). Signs include vomiting, diarrhoea, drooling, incoordination and dermatitis.
General gardening information, not professional advice. Plant toxicity details are a starting point, not veterinary or medical advice: if a pet or child may have eaten a plant, contact a veterinarian or doctor promptly.
Care level: NC State’s maintenance rating (Medium). Pot band and summary wording are ours, based on the sources below.