The Kalanchoe blossfeldiana, commonly known as the Florist Kalanchoe, is a popular flowering houseplant. This succulent, native to Madagascar, is prized for its clusters of vibrant, small flowers that provide color during the winter months. A primary reason for its popularity is its impressive bloom time, which is relatively long for an indoor plant. Under typical indoor conditions, the initial bloom on a newly purchased plant will last approximately six to eight weeks, though this period can sometimes extend for months with specialized care.
Extending the Current Bloom
Maximizing the longevity of the existing flowers depends on replicating the plant’s ideal environmental conditions while it is actively blooming. The correct placement involves providing the plant with bright, yet indirect, sunlight throughout the day. Kalanchoe needs several hours of light to fuel flowering, but exposure to harsh, direct midday sun can scorch the foliage and shorten the bloom duration. A location near a bright window, such as an east-facing one, or slightly set back from a south-facing window, is often the best choice.
Temperature regulation also plays a significant role in prolonging the display of flowers. Cooler temperatures, particularly overnight, help the blossoms last longer by slowing down the plant’s metabolism. Ideally, the plant should be kept in a location where the temperature remains around 70°F during the day.
Nighttime temperatures around 50°F to 60°F are particularly beneficial for extending the bloom period. Temperatures consistently above 75°F can cause the flowers to fade more quickly. It is important to keep the plant away from any drafts, as sudden temperature fluctuations can stress the plant.
Watering practices are equally important for a plant that is actively flowering. The most common mistake is overwatering, which leads to root rot and premature flower drop. The soil should be allowed to dry out almost completely between waterings, typically until the top one or two inches feel dry to the touch. When watering, do so thoroughly until the water drains from the bottom, and then ensure the plant is not left sitting in a saucer of excess water.
Handling Spent Flowers and Pruning
Once the initial flowering has concluded, physical maintenance is necessary to prepare the plant for a new cycle of growth. The first step is deadheading, which involves removing individual spent flowers as they wither. This prevents the plant from wasting energy attempting to produce seeds.
Remove the entire stalk once all blossoms on it have faded. This is best accomplished by cutting the flower stem back to the second or third leaf node below the spent cluster, or all the way down to the main stem. Using clean, sharp scissors or a pruning tool ensures a clean cut that helps prevent disease.
After the initial cleanup, light structural pruning may be needed if the plant has grown tall and leggy. Cutting back stems by about one-third encourages the plant to branch out, resulting in a bushier, more compact shape. Making these cuts just above a leaf node promotes the formation of new growth in that spot. This physical maintenance prepares the plant for a period of rest and the specialized treatment required to force a new bloom.
Forcing the Plant to Rebloom
Getting a Kalanchoe to bloom again requires understanding its nature as a short-day plant. This means that the formation of flower buds is triggered by exposure to long, uninterrupted periods of darkness, mimicking the shorter days of late fall and winter. This light manipulation is required for approximately six to eight weeks before the desired bloom time.
The requirement is a minimum of 12 to 14 hours of complete, uninterrupted darkness every 24-hour cycle. Even a brief flash of light from a streetlamp or a door opening can interrupt the photoperiod and delay or prevent flower bud initiation. For the remaining 10 to 12 hours of the day, the plant must receive bright, indirect light to photosynthesize and store energy.
A common technique is placing the plant in a dark closet or covering it with an opaque box every evening. This routine must be strictly adhered to for the entire six to eight-week period. During this controlled dark period, it is also beneficial to keep the ambient temperature slightly cooler, around 60°F at night, which further encourages flower bud development.
Once tiny flower buds become visible, usually after the six to eight-week treatment, the cycle of strict darkness can be discontinued. The plant should then be moved back to a location where it receives bright, indirect light and normal watering can resume. This consistent care will allow the newly formed buds to mature and open.