What is a chrysanthemum?
The chrysanthemum (Chrysanthemum morifolium), often called a mum or pot chrysanthemum, is one of the most widely grown flowering plants in the world. Originally cultivated in China over 2,500 years ago, it belongs to the daisy family (Asteraceae) and now exists in thousands of cultivars spanning pompom, anemone, spider, spoon, and cushion flower forms. Indoors, it is most often sold as a compact blooming pot plant in autumn, in a kaleidoscope of reds, oranges, yellows, purples, and whites.
How much light does a chrysanthemum need?
Chrysanthemums are long-night plants — they initiate flower buds only when day length drops below roughly 14.5 hours, which is why they bloom naturally in autumn. Once in bud, they need bright, indirect light to sustain that bloom indoors. A south- or east-facing windowsill is ideal. Avoid harsh direct afternoon sun, which fades petals and wilts flowers; equally avoid deep shade, which produces weak, leggy growth and shortens blooms.
How often should you water a chrysanthemum?
Water a potted chrysanthemum every three to five days, or when the top inch of compost feels dry to the touch. Give it a thorough drink so water drains freely from the bottom, then empty the saucer. Chrysanthemums are thirsty plants with dense root systems, but they are equally intolerant of sitting in stagnant water — root rot is a common killer. In a warm, sunny spot you may need to water more frequently, especially during active bloom.
Why are cool temperatures the secret to longer blooms?
Temperature is the most underrated factor in chrysanthemum care. At 50–60°F (10–15°C) the flowers last dramatically longer — often double the time compared to a warm living room at 72°F. Growers exploit this by finishing plants in cool glasshouses. Indoors, placing your mum on a cool windowsill away from heating vents, or even moving it to an unheated porch on mild nights, can extend a bloom display from three weeks to six or eight weeks.
How do you care for a chrysanthemum after it blooms?
Most florist chrysanthemums are sold as temporary seasonal color, but they can be kept. Once flowers finish, cut stems back to about 4 inches (10 cm), keep the plant barely moist in a cool bright spot through winter, then repot with fresh compost in spring. Harden the plant off and move it outdoors after the last frost. Hardy “garden mum” types survive winter in the ground in USDA zones 5–9; tender florist types are best treated as annuals or brought back in before frost.
Are chrysanthemums toxic to pets?
Yes — the ASPCA lists chrysanthemums as toxic to cats and dogs. The plants contain pyrethrins and sesquiterpene lactones, compounds that can cause vomiting, diarrhea, excessive drooling, and skin irritation in animals that chew or ingest any part of the plant. Keep mums on high shelves or in rooms that pets cannot access, especially during the autumn gifting season when they are most commonly brought indoors.