Senecio tropaeolifolius, often known as Nasturtium-leaf Senecio or False Nasturtium, is a distinctive succulent plant recognized for its unusual foliage and trailing habit. Native to South Africa, this species develops a unique swollen base, called a caudex, over time. Its appeal lies in this sculptural quality and the vibrant blooms it produces.
Identification and Unique Characteristics
Senecio tropaeolifolius features thick, succulent leaves that resemble those of garden nasturtiums. These leaves are typically pentagonal with sharp corners, sometimes exhibiting reddish undersides or margins. The plant grows as a small succulent, reaching up to 8 inches (20 cm) tall and spreading up to 24 inches (60 cm) wide, forming a dense clump.
Mature plants produce terminal clusters of bright yellow, daisy-like flowers on lax spikes that can extend up to 2 inches (5 cm) in length. These blooms typically appear from fall to winter. Over time, the plant develops a prominent, woody caudex, which can be exposed for a bonsai-like appearance.
Care Requirements
Light
Senecio tropaeolifolius thrives in bright, indirect light conditions. It can tolerate some direct morning sun but should be shielded from harsh afternoon sun, which can scorch its leaves. Adequate light encourages compact growth and can enhance the reddish coloration on the leaves. Insufficient light may lead to leggy growth.
Watering
As a succulent, Senecio tropaeolifolius requires careful watering to prevent root rot. Allow the soil to dry out completely between waterings during its active growing season. Signs of overwatering include yellowing leaves and soft or mushy stems, while shriveling leaves can indicate dehydration. During winter dormancy, watering should be significantly reduced to protect the caudex from rot.
Soil
This plant performs best in a well-draining, gritty soil mix that allows excess water to escape quickly. A blend formulated for succulents or cacti is ideal, often incorporating materials like perlite, pumice, or coarse sand to improve drainage and aeration. Senecio tropaeolifolius cannot tolerate soggy conditions. Avoid potting mixes with added fertilizers, as their nutrient levels may be too high and their drainage properties insufficient for succulents.
Temperature and Humidity
Senecio tropaeolifolius prefers warm temperatures and is hardy in USDA zones 9b to 11b, tolerating temperatures from 25 °F (-3.9 °C) to 50 °F (10 °C). It is sensitive to frost, so bring it indoors during winter in colder climates. Most Senecio species thrive in typical indoor temperatures ranging from 65°F to 75°F (18°C to 24°C), and it is important to keep them above 50°F (10°C). The plant prefers low to medium humidity levels, typically 30-50%.
Fertilizing
Senecio tropaeolifolius is not a heavy feeder and can thrive in nutrient-poor soils. Fertilize sparingly, typically once a year during the spring or growing season. Use a diluted liquid fertilizer specifically formulated for succulents and cacti. Over-fertilizing can lead to leggy growth and yellowing leaves due to fertilizer burn.
Propagation
Propagating Senecio tropaeolifolius is most effectively achieved through stem cuttings. Take cuttings during the plant’s active growing season, from early spring to fall. Select a healthy stem and cut a segment at least 6 inches long, just below a leaf node.
Allow the cut end to dry and form a callus for a few days to prevent rot when planted. Once callused, plant the cutting in a well-draining succulent or cacti potting mix. Water lightly until roots develop, then transition to a regular watering schedule.
Common Issues and Solutions
One common issue for Senecio tropaeolifolius is root rot, primarily caused by overwatering. Signs include mushy stems and yellowing leaves; address this by reducing watering frequency and ensuring proper drainage. Leggy growth, characterized by stretched stems, indicates insufficient light; move the plant to a brighter location. Pests like mealybugs and aphids can occasionally affect the plant. These can be dislodged with a strong stream of water or treated with insecticidal soap.
Toxicity Information
Senecio tropaeolifolius contains compounds that can be toxic if ingested. This plant is considered mildly to severely toxic to humans and pets, such as dogs and cats. Ingestion by pets can lead to symptoms including vomiting, diarrhea, drooling, loss of appetite, and abdominal pain.
Contact with the sap may also cause skin irritation. Keep Senecio tropaeolifolius out of reach of children and pets. If ingestion is suspected, contact a medical professional or veterinarian immediately.