Multi-colored flowers, spectacular leaves and still easy-care - no wonder that the multi-faceted Kalanchoe bring the joy!
The Kalanchoe genus from the Crassulaceae family not only includes Kalanchoe, but also representatives from the Bryophyllum family. Moreover, it is not possible to clearly assign every one of the 200 different species to one group. This somewhat complicated situation is due to the fact that no taxonomic classification has yet been carried out for this genus. Indeed, the first plants had very different names: In the 18th century they were known as Cotyledon, from 1805 as Bryophyllum, which around 80 years later migrated to the Kalanchoe genus. The amalgamation occurred in the middle of the 20th century.
The natural location provides a small indication as to the affiliation of the individual plants. Because although Bryophyllum species only grow on Madagascar, Kalanchoe are also native to the tropics and south-east of the African continent and Asia, as well as the Arabian peninsular. At our latitudes, all species are kept as houseplants. The best known without a doubt is the Flaming Katy (Kalanchoe blossfeldiana), which decorates window ledges. Some species, including the Flaming Katy, are poisonous to both people and animals.
Appearance and Growth
Kalanchoe are generally perennial in their natural location, more rarely they are annual or bi-annual plants, bushes, or even trees. A few select species belong to the epiphytes, meaning they grow on the surface of other plants. However, the majority of the Kalanchoe genus grow with fibrous roots fixed firmly in the soil. The fleshy, sometimes basally woody plant stems usually have several branches and are vertical to flat lying, depending on the species. The equally fleshy leaves - Kalanchoe are considered succulents – are single or clumped together and generally positioned opposite decussate or sometimes also on the shoots. The leaf margins are rarely smooth but sometimes serrated or crenate. In some species the flower buds are directly on the leaf margins.
The monoecious flowers open on the standing (usually with Kalanchoe) or hanging (typical for Bryophyllum) stems. They each consist of four more or less intergrown sepals and petals that grow together into a tube and have conspicuous, vibrant colors. The tips of the petals are bent backwards. As short-day plants, Kalanchoe only flower if there are fewer than 12 hours of daylight. If pollination occurs, after flowering four upright follicle fruits form, containing many tiny seeds.
Location and Substrate
All species of Kalanchoe enjoy a bright place all year round. In addition, temperatures should remain evenly warm between 64.4 and 68 degrees Fahrenheit. It should only be few degrees cooler in the winter, but then never below 53.6 degrees Fahrenheit. This promotes flower formation and more compact growth. The plants can be happily taken from the window ledge and moved outside in the summer. However, you should first place them in a slightly shady place in the garden until the leaves have become accustomed to the sunlight. You can also make use of the number of daylight hours to encourage the short-day plants to flower earlier: After about six weeks with a maximum of nine hours of daylight - just put a box or dark bucket over the houseplants - it’s time!
As succulents, most representatives of the Kalanchoe genus need highly permeable and leaner soil. You can’t go wrong with ready-mixed cactus substrate. If you prefer to make your own mixture, mix equal amounts of normal potting soil, sand and clay granulate or pumice gravel.
As already mentioned, the houseplants can be planted in permeable cactus or self-mixed soil. It is very important that there is sufficient water drainage at the bottom of the pots to ensure that the Kalanchoe roots do not become waterlogged. You can additionally ensure this by first filling the container with a drainage layer a few inches thick from expanding clay or gravel.
One reason Kalanchoe plants are so popular is because they are so easy-care. This makes them the perfect houseplant for beginners. Nonetheless, the succulents require regular watering, although the substrate should always dry out between watering. As the plants can store water, they can withstand droughts much more easily than the damp. They should also be given less water, less frequently in the fall and over the winter.
Fertilizing also requires a light touch. You can put liquid cactus fertilizer in the water for Flaming Katy every two to three weeks. Most other Kalanchoe species should be fertilized once a month at the most. They do not require any fertilizer in the winter.
If you want to prune your houseplants, for example to keep them more compact, you can do this in the spring or summer. Wear gloves when pruning species with irritating or poisonous sap, such as the Bryophyllum. Wear gloves when repotting as well, although repotting is only necessary when the pot has become much too small. This will almost certainly be the case if you have acquired a Kalanchoe as a mini plant. You should replant these in a new container with fresh soil as soon as possible after purchasing.
Important Species and Varieties
The Flaming Katy is a true classic which can be found on almost every window ledge (Kalanchoe blossfeldiana). This species is called Madagascar widow’s thrill after its native home. The cheerful, colored flowers in red, pink, orange, yellow, and white that protrude vibrantly from the thick-fleshed, dark green leaves contribute in particular to the popularity of this plant. Although they belong to the short-day plants, they can be found flowering in trade shops all year round. There are now Flaming Katy plants that grow to around 11.81 inches tall, both double-flowered or as cut flowers.
The Madagascan native Bryophyllum (Kalanchoe daigremontiana or also Bryophyllum daigremontuanum) is also popular with its hanging, red bell flowers which protrude in a long, stemmed panicle from the center of the plant. However, the tiny plantlets that form on the margins of the fleshy, triangular leaves and change color from green to purple are even more fascinating. The 11.81 (with flower) to 59.06 inch tall Bryophyllum is often mistaken for the Kalanchoe pinnata. It is used in anthropological medicine , however its sap also contains a toxic steroid.
In German this plant is named after Johann Wolfgang von Goethe (Kalanchoe pinnata or Bryophyllum pinnatum), who actually loved it. It is often confused with the Bryophyllum due to the tiny plantlets which sit on the round, serrated leaf margins. The upright, up to 3.3 feet tall Kalanchoe pinnata opens its delicate flower bells in green-red to green-purple sitting on loose cymes in late summer. As with the Bryophyllum, Kalanchoe pinnata is used in anthropological medicine, among other things.
Kalanchoe tomentosa rarely flowers as a houseplant, instead, it decorates itself with felted-white haired, elongated oval leaves with rusty-red to dark brown colored margins. Panda plants grow 15.75 to 19.69 inches tall on window ledges.
The Kalanchoe beharensis, felt bush, is also popular with its special leaves. These are large, with velvety felt and silver-gray or bronze colored, slightly fleshy and triangular. The foliage sits on a woody, upright and rarely branched stem. The basal leaves are dropped over time creating a trunk. This Madagascan native houseplant grows 19.69 to 23.62 inches tall.
The paddle plant (Kalanchoe thyrsiflora), which originates from South Africa and Botswana, is also characterized by striking leaves. It is a bi-annual plant. It actually forms a sort of rosette from wide, fleshy, gray-green leaves in the first year. In the following year it flowers and then dies. However, as the flowers are an extremely rare appearance on houseplants, the lifespan of the paddle plant is extended.
Propagation is simple with Bryophyllum and Kalanchoe pinnata: The plantlets on the leaf margins drop when they are fully developed and root into the soil. This can be really bothersome! Other species, such as the Flaming Katy, are propagated with cuttings. These cuttings are taken with two or three leaf pairs in the summer and planted in a soil-sand mixture. At a good 68 degrees Fahrenheit they soon form roots.
Diseases and Pests
Kalanchoe plants are extremely robust plants that essentially only fall foul of one thing: too much water and in particular waterlogging, which causes the roots to quickly rot. Mealy bugs are a rare occurrence and are usually the result of incorrect care and an unfavorable location.