Potted chrysanthemums -- also known as "mums" -- are forced into flowering year-round, but they bloom naturally in autumn. They blossom for up to a month with proper care. Many plants also bloom a second time the following autumn if correctly tended. The bright flowers come in a variety of colours and petal shapes, but all chrysanthemums have the same basic care requirements.
Chrysanthemums require bright light but cannot tolerate direct sunlight. An area near a sunny window out of the direct rays of the sun provides optimum lighting. The plants tolerate indoor temperatures, but the flowers survive longest with a temperature between 18C and 24C during the day and 12C cooler than this during the night. The cooler night temperatures allow the plant to rest and extend blossom life.
Water and fertiliser
Wilting foliage from dry soil conditions inhibits flowering, kills existing flowers and weakens the chrysanthemum. The plants need watering when the soil surface begins drying out but before the soil dries completely. Mums need watering every one to three days, depending on how quickly the soil dries. Chrysanthemums typically require no fertiliser, but a dilute application of a soluble houseplant fertiliser formulated for flowering plants every two weeks may improve the plant's success for reblooming later.
Pruning serves two purposes. It improves the appearance of the plant and prevents diseases. Removing the spent flowers as soon as they begin to wilt and cutting out any dead foliage is usually all that is required to keep the chrysanthemum looking its best during blooming. The mums also require pinching if you plant to bloom them a second time. Pinch off the tip of each new stem beginning in spring. Continue to pinch until mid-summer when the plant begins producing new buds.
Indoor conditions don't provide for the chrysanthemum's needs if you wish to rebloom the plant. Moving the plant outdoors after spring frost dangers provides it with the light and temperatures required for healthy growth. Place the pots in an area where they receive at least six hours of sunlight. Continue watering and fertilising the plants through the summer. Potted mums can't tolerate frost, so bring them indoors in autumn before the first frost. Chrysanthemums typically bloom again in late October or November.