Throughout the first 100 years of Kalanchoe Culture, all Kalanchoes had 4-petaled flowers. Then in 1998, a Swedish retailer of Kalanchoes reported to his supplier that he had found a curious specimen in a lot of plants of ‘Bromo’, a cultivar with purple flowers. Instead of the normal 4 petals, this mutation had 32 petals, forming a small rose.
This mutation was launched as a cultivar under the name ‘Leonardo’ and was at the origin of a major hybridizing program, leading in 2002 to the launching of a new series of fully double Kalanchoes, Calandiva.
Six cultivars were introduced the first year, but others followed and now the series includes 50 cultivars in different shades of red, pink, orange, purple and white, although only 25 are still listed in the catalog of the Dutch supplier. Calandivas took the indoor gardening world by storm and are are now the best selling Kalanchoes in the world.
Calandivas are available all year round, not just at Christmas. When you buy them, they are compact plants forming a dense rosette whose center is entirely hidden by flowers. The flowers are not only gorgeous, but they remain in bloom 6 weeks or more and the plant only requires minimal care.
Growing Conditions and General Care
Like other succulents, Calandiva needs well-draining soil, with a slightly acidic or neutral pH level. Add sand or perlite to your potting soil or buy a blend made for succulents and cacti. Plant Calandiva outdoors, about 8 to 12 inches (20 to 30 cm) apart.
Give the plant full sun outdoors and as much sunlight as you can indoors, either with direct sunlight or bright, indirect sunlight. A spindly looking plant may result from too little light.
Because Calandiva is a drought-tolerant plant, it’s best to err on the side of too little water rather than too much. Water the plant thoroughly every week, or less, but wait until the soil is dry before rewatering.
Apply a balanced fertilizer once a month during the growing season to encourage flowering, using a liquid fertilizer for an indoor plant and either a liquid or granular type for outdoor plants.
Minor pruning and pinching are all Calandiva needs to encourage flowering and create a more bushy, full shape. Cut back the tallish stems that rise above the leaves after the flowers finish blooming. Leave small, new plant shoots that form at the ends of the leaves remaining if you want your plant to grow larger. Or remove those plantlets and plant them directly in moist soil to propagate new plants.
Flowering Requirements Indoors
Calandiva needs long nights, from 14 to 16 hours of darkness, and short days to develop flower buds, which form during the late fall and winter months. If possible, keep indoor plants out of artificial light during the winter by placing them in a dark room or closet from the late afternoon until morning. Once the buds form, let the plant remain anywhere and look for the first blossoms on your plant in January.
Pests and Diseases
Problems with pets and diseases are minor with Calandiva, but the plants can develop powdery mildew or stem rot from overwatering. If your plant has discolored leaves or you see furry web-like substances, the problem could be powdery mildew.
If the leaves are just wilted, the plant may have root rot. In either case, consider whether the soil is too wet and cut back on watering or apply a commercial product as directed on the package for powdery mildew. If you see small bugs on the plant, such as aphids, brown scale or mealybugs, wipe them off gently by hand.
Source: sfgate.com