Kalanchoe is a common name used for any plant in the botanical genus Kalanchoe or Bryophyllum. North Americans may be most familiar with the florist kalanchoe (Kalanchoe blossfeldiana), which is sold in small containers with large clusters of brightly coloured flowers. All kalanchoe plants, regardless of species, are tropical plants. They do not tolerate frosts or freezes and thus are grown as houseplants in the United States unless you live where winter frosts never occur.
When grown as houseplants, kalanchoe plants are grown in soil-based potting mixes that have gritty texture. During the long summer days, water them to keep the soil evenly moist, but never soggy. Place them in bright filtered light indoors or where they receive two to four hours of direct sun rays. From fall to spring, water kalanchoe plants less and don't fertilise. Flowering tends to increase during the shorter days from fall to spring.
In USDA Plant Hardiness Zones 10 and warmer where winter frosts and freezes are rare or absent, grow kalanchoes outdoors year round in containers or mixed perennial borders. Plant them in sandy or loamy soils with organic matter that drain water quickly. They look their best when shielded from hot sunlight, so a partial shade to partial sun exposure is best -- between four to eight hours of sunlight daily.
Besides the colourful blooming florist kalanchoe, a few other species are often encountered in gardens or as houseplants. Felt bush (Kalanchoe beharensis) bears large, stiff, oaklike leaves that are coated in a feltlike grey covering. Chandelier plant (Kalanchoe delagoensis) sends up tall flower spikes lined in drooping flowers on a branching structure that resembles a narrow chandelier fixture. Flapjack (Kalanchoe thrysiflora) bears rounded, flat leaves that are greyish light green that bronze in intense sun rays. Mother-of-thousands (Kalanchoe daigremontiana) grows upright with pointed leaves lined in tiny plantlets on leaf edges that drop to the ground and become new plants.
Florist kalanchoe may be kept as a long-term houseplant and will rebloom if basic care is followed. The heaviest blooming occurs from September to March and, if you clip out the delicate stems of old flowers, the plant will produce more flowers if the day length isn't too long. From May to August in the United States, cut back florist kalanchoe houseplants to rejuvenate into bushy plants. Flowering naturally follows in fall once days become shorter.