Kalanchoe houghtonii is a unique succulent commonly recognized by several names, including Mother of Millions Hybrid and Mother of Thousands. This distinctive plant originated from a hybrid cross in the United States during the 1930s, involving two species, Kalanchoe daigremontiana and Kalanchoe delagoensis, both native to Madagascar. Its most notable characteristic is the prolific production of tiny plantlets that form along the margins of its leaves. This feature contributes to its widespread appeal as a houseplant.
Identifying Kalanchoe houghtonii
Kalanchoe houghtonii has fleshy, boat-shaped leaves, typically emerald green to brownish-green, often with purple splotches on their undersides. These leaves have serrated margins, where numerous small plantlets, or bulbils, develop. The plant grows with an upright, unbranched stem, reaching up to 30 inches (75 cm) tall.
Mature plants can produce a tall flower stalk. The flowers are pendulous and bell-shaped, appearing in shades of red, orange, pinkish-yellow, or pink. This monocarpic succulent flowers in late winter to early spring, after which the main plant may decline.
Kalanchoe houghtonii Care
Light
Kalanchoe houghtonii thrives in bright, indirect sunlight. Direct, intense sunlight can scorch the leaf tips. If grown outdoors, limit direct sun exposure to a few hours per day, particularly during the strongest afternoon sun.
Soil
A well-draining soil mix is important for Kalanchoe houghtonii to prevent root rot. A cactus or succulent potting mix is suitable, or you can create your own by combining ordinary potting soil with coarse sand, perlite, or pumice. This blend ensures proper drainage and aeration. Avoid soil mixtures with excessive organic matter that retain too much moisture.
Water
Water infrequently, allowing the soil to dry out completely between waterings. Use the soak-and-dry method: water thoroughly until excess drains from the bottom, then wait until the soil is dry before watering again. Overwatering is a common issue that can lead to root rot, so it is safer to underwater this drought-tolerant succulent. During the active growing season (spring and summer), water every 10-14 days, reducing frequency to every 3-4 weeks in fall and winter.
Temperature and Humidity
Kalanchoe houghtonii prefers warm temperatures, between 60-85°F (15-29°C). It is a tender succulent and will not tolerate hard frosts. If temperatures drop below 50°F (10°C), bring outdoor plants indoors. Average indoor humidity levels are suitable, as these plants do not require high humidity.
Fertilizer
Fertilization requirements for Kalanchoe houghtonii are minimal. During the active growing season (spring and summer), apply a balanced liquid fertilizer diluted to half or quarter strength. Fertilizing once every few months is sufficient. Avoid fertilizing during the dormant winter months, as excessive nutrients can be detrimental and lead to root burn.
Propagation and Prolific Growth
Kalanchoe houghtonii is known for its ability to propagate itself, primarily through the numerous small plantlets that form along the margins of its leaves. These plantlets, also known as bulbils or propagules, are miniature versions of the parent plant, complete with tiny roots. They readily detach from the parent leaf and fall to the surrounding soil.
Once on the soil surface, these plantlets quickly root and establish themselves, leading to the rapid proliferation of new plants. This vegetative reproduction contributes to the plant’s prolific growth. Stem and leaf cuttings can also be used for propagation, with stems rooting easily and leaves developing into new plants when placed on soil.
Managing Its Invasive Nature
The prolific plantlet production of Kalanchoe houghtonii is a significant factor in its invasive potential, particularly in warmer climates. Its rapid spread can lead to a reduction in native plant diversity and disruption of ecological balances, especially in coastal dune habitats where it can form dense mats.
To manage its spread, especially in regions where it can naturalize, it is recommended to grow Kalanchoe houghtonii in containers. This practice helps contain the plantlets and prevents them from escaping into the environment. When disposing of plant material, including fallen plantlets, do so responsibly, avoiding composting or discarding them in garden waste that could lead to further spread. Hand-pulling can be effective for removing established plants, but ensuring all plant material, especially plantlets, is securely contained and disposed of helps prevent re-establishment.
Toxicity Considerations
Kalanchoe houghtonii, like many species within the Kalanchoe genus, contains cardiac glycosides known as bufadienolides, making it toxic if ingested. All parts of the plant contain these toxins, with concentrations often higher in the flowers. Ingestion by pets, particularly cats and dogs, can lead to serious health issues.
Symptoms of poisoning in animals may include vomiting, diarrhea, excessive drooling, weakness, lethargy, and changes in heart rate. In severe cases, cardiac issues, seizures, and even death can occur. While less common, human ingestion can also cause gastrointestinal upset, such as nausea and vomiting. It is important to keep Kalanchoe houghtonii plants out of reach of children and pets to prevent accidental ingestion.