Chrysanthemums (mums) are favored seasonal plants, recognized for their vibrant, late-season blooms that arrive during autumn. While commonly seen in outdoor gardens, it is possible to grow chrysanthemums indoors as temporary houseplants. Success requires careful management of their environment, particularly replicating the precise light and temperature conditions needed to prompt flowering.
Essential Environmental Needs
Chrysanthemums require significant light exposure to maintain healthy foliage and produce abundant flowers. During their blooming period, they thrive in bright, indirect light, ideally placed near a south or west-facing window where they can receive several hours of sun. Insufficient light can quickly lead to an undesirable “leggy” growth habit, characterized by long, weak stems and a decrease in flower development.
The indoor environment’s temperature is equally important for prolonging the flower display. Chrysanthemums prefer cooler conditions, with ideal daytime temperatures ranging from 60°F to 70°F (15°C to 21°C). Nighttime temperatures should drop slightly, ideally between 50°F and 60°F (10°C to 15°C). Keep the potted plant away from heat sources like radiators or heating vents, as excessive warmth and fluctuations prematurely dry out blooms and shorten the flowering time.
Proper Watering and Soil Maintenance
Effective watering is a delicate balance for indoor chrysanthemums; they are thirsty plants but highly susceptible to root rot if overwatered. The soil must be kept consistently moist but never soggy or waterlogged. Use the “finger test,” watering thoroughly only when the top inch of soil feels dry to the touch.
The container must have adequate drainage holes to prevent the plant from sitting in standing water after irrigation. If using a saucer, empty any excess water within an hour to ensure proper root aeration. The best potting medium is a well-draining mix, often peat-based and amended with perlite or vermiculite to prevent compaction. Florist mums purchased in bloom require minimal or no fertilizer during their brief display life.
Post-Bloom Care for Longevity
Once the flowers fade, attention shifts to maintenance. Deadheading involves promptly removing spent blooms to redirect the plant’s energy away from seed production. After the flowering season is finished, the stems should be cut back—often called the “hard chop”—to about four to six inches above the soil line.
Following this pruning, the plant requires a period of dormancy to conserve energy for future growth. Move the chrysanthemum to a cool, dark location where temperatures are maintained around 38°F to 50°F (3°C to 10°C) for the winter months. During this rest period, significantly reduce watering, providing only enough moisture to prevent the soil from drying out completely.
Attempting to force a chrysanthemum to re-bloom indoors is challenging because the plant is photoperiodic. To set new buds, the plant requires a strict schedule of 12 to 14 hours of uninterrupted darkness daily for several weeks. Achieving this precise light control in a typical home environment is often tedious. Many indoor gardeners choose to purchase new blooming plants each season rather than manage the complex re-blooming process.