Overview
Marsdenia rubicunda (K.Schum.) N.E.Br. is a flowering plant species that belongs to the family Apocynaceae. It is a twining climber with attractive flowers that has gained popularity among gardeners around the world due to its showy blooms and ease of cultivation.
Origin and Common Names
Marsdenia rubicunda (K.Schum.) N.E.Br. is native to tropical and southern Africa, specifically found in countries such as Tanzania, Zambia, Malawi, Zimbabwe, and Mozambique. The plant is commonly referred to with various names, such as the red milk vine, matanto, mawadi, and mbarani.
Appearance
The plant grows up to 3 meters long in height, and it is a twining climber with thin stems. The leaves are elongated, pointed, and measure up to 17 centimeters long by 7 centimeters wide. The flowers are bell-shaped, bright red, and grow in dense clusters. The plants typically bloom from mid-summer to late autumn.
Uses
Although Marsdenia rubicunda (K.Schum.) N.E.Br. is mainly grown for its ornamental value, it also has several medicinal properties. The plant’s extract can be used to manage a range of conditions such as diarrhea, fever, and stomach upsets. Furthermore, the local communities in Africa use the sap from the plant to treat snake bites and wounds.
In addition to its medicinal value, Marsdenia rubicunda (K.Schum.) N.E.Br. also has some cultural importance. For instance, in Tanzania, the plant is used as a symbol of love, and it is given to friends and family as a sign of appreciation.
Light Conditions
Marsdenia rubicunda is a plant that prefers bright, filtered light. Direct sunlight can be too intense and damaging for the plant's foliage. A location with bright, indirect light or partial shade is optimal for the plant's growth.
Temperature Requirements
The plant thrives in warm temperatures, with a preferred range between 20 to 30°C (68 to 86°F) during the day and a minimum of 16°C (60°F) during the night. However, it can tolerate temperature fluctuations to a certain extent. It is recommended to avoid exposing the plant to extreme temperatures as it can damage the foliage and affect the plant's growth.
Soil Requirements
Marsdenia rubicunda prefers well-draining soil that is slightly acidic to neutral. The soil should be moist but not waterlogged. The addition of organic matter, such as compost, can improve soil drainage and provide essential nutrients for the plant's growth. It is also recommended to avoid using heavy clay or sandy soils as they can impact the plant's growth and development.
Cultivation
Marsdenia rubicunda is a plant that thrives in tropical regions. It requires warm temperatures and plenty of sunlight to grow. The plant is best grown in well-draining soil with high organic matter. It can be grown in containers or in the ground.
If planting in the ground, ensure that the soil is well-draining and add compost or humus to ensure adequate nutrition. If planting in a container, use a pot with drainage holes and fill it with a mix of peat moss, perlite, and vermiculite.
Plant the Marsdenia rubicunda in the chosen location at a depth of about 1 inch. Make sure to space each plant at least 18 inches apart to facilitate proper growth.
Watering Needs
Marsdenia rubicunda requires regular watering, especially during the dry season or when grown in containers. The soil should be kept moist but not waterlogged to prevent root rot. If the topsoil feels dry, water the plant with enough water to ensure that the entire root system is well-saturated.
It is essential to avoid overhead watering as it can lead to the spread of fungal diseases. Instead, water the plant at the base to prevent wetting the leaves. During the rainy season, reduce watering to prevent waterlogging as this can lead to root rot and other plant diseases.
Fertilization
Marsdenia rubicunda requires regular feeding to thrive. Use a slow-release fertilizer with a balanced N-P-K ratio, such as 10-10-10. The plant should be fertilized at least once a month during the growing season, which typically runs from spring to summer.
When applying fertilizers, ensure that you follow the manufacturer's instructions to avoid burning the plant's roots. Fertilizers should be applied on moist soil and then watered in to ensure that the nutrients are taken up by the roots.
Pruning
Marsdenia rubicunda may require pruning to remove dead or diseased growth, or to shape the plant. Prune the plant in early spring or late winter before new growth begins. Use clean, sharp pruning shears to make clean cuts and prevent the spread of diseases.
When pruning, focus on removing any dead or damaged stems and those that detract from the overall appearance of the plant. Cut the stems just above a leaf node or lateral bud to promote new growth.
Regular pruning can help keep Marsdenia rubicunda compact and prevent it from becoming too leggy or sprawling. However, do not over-prune the plant as this can disrupt its natural growth and affect its overall health.
Propagation of Marsdenia rubicunda
Marsdenia rubicunda (K.Schum.) N.E.Br. can be propagated through both sexual and asexual methods.
Sexual Propagation
Seeds are the common method of sexual propagation for Marsdenia rubicunda. These seeds are can be harvested from the plant's fruits that have ripened and turned brown. Once collected, the seeds should be cleaned and dried in a shaded area. Sowing should be done during the rainy season or by providing the seeds with a sufficient amount of water. The seeds will start germinating between two to five weeks from sowing.
Asexual Propagation
Marsdenia rubicunda can be propagated asexually through stem cuttings. Cuttings taken from the middle part of the stem, approximately 20 cm long and with at least two to three nodes, are ideal. The cuttings are dipped in a rooting hormone that helps to speed up the rooting process. The cuttings are then planted in a well-draining and fertile soil mix, misted with water, and kept in a shaded area with high humidity to ensure proper growth and development.
Another asexual propagation method is layering. This process involves bending a lower branch of the plant down to the soil. A small cut is made in the branch, and the area is covered with soil. After the roots have formed, the branch can be cut and planted in a new location.
Disease Management
Marsdenia rubicunda is vulnerable to several diseases that can damage the plant's development and reduce its yield. The primary diseases that affect this plant are:
- Anthracnose: Colletotrichum gloeosporioides is the primary fungal pathogen that causes anthracnose in Marsdenia rubicunda. Symptoms include circular, sunken lesions on the stems, leaves, flowers, and fruits. The infected plant parts eventually atrophy and die. To manage this disease, remove and destroy all infected plant parts and apply copper-based fungicides.
- Rust: The fungal pathogen Puccinia marsdeniae causes rust in Marsdenia rubicunda. Symptoms include yellow-orange pustules on the undersides of leaves and stems, which later turn brown and cause early leaf drop. To manage this disease, use copper-based fungicides and maintain proper plant spacing and ventilation to avoid high humidity levels.
- Leaf spot: The fungal pathogen Cercospora marsdeniae causes leaf spot in Marsdenia rubicunda. Symptoms appear as circular, dark-brown spots on the leaves, which later expand and coalesce, causing leaf drop. To manage this disease, ensure proper sanitation practices, remove affected leaves, and apply copper-based fungicides.
Pest Management
Marsdenia rubicunda is also susceptible to several pests that can damage the plant's foliage, flowers, and fruits. The primary pests that affect this plant are:
- Spider mites: These tiny pests suck sap from the undersides of leaves, causing yellowing and leaf drop. To manage this pest, spray the plant with insecticidal soap or neem oil, maintain proper plant hygiene, and avoid over-fertilizing.
- Scale insects: These pests attach themselves to the stems and leaves and suck plant sap, causing chlorosis and leaf drop. To manage this pest, remove the scales manually, apply horticultural oil or insecticidal soap to the plant, and maintain plant hygiene and proper watering practices.
- Mealybugs: These pests form white, cottony masses on the plant's foliage and stems and suck sap, causing leaf yellowing and stunted growth. To manage this pest, remove the mealybugs manually, spray the plant with insecticidal soap or neem oil, and maintain proper plant hygiene.
