Overview
Senecio johnstonii Oliv. var. johnstonii is a perennial plant that belongs to the family Asteraceae. It is an evergreen succulent that has a sprawling growth habit, with stems that are up to 3 meters long. This plant is native to the Eastern Cape Province of South Africa.
Common Names
Senecio johnstonii Oliv. var. johnstonii is commonly known as Johnston's Senecio or Ivy-leaved Senecio.
Appearance
The leaves of Senecio johnstonii Oliv. var. johnstonii are fleshy, succulent, and glossy. The leaves are normally green, but they may become reddish in full sun. The leaf blade is up to 15 cm long and 10 cm wide with a slightly lobed margin. The inflorescence of this plant consists of yellow flowers that are about 2 cm in diameter.
Uses
Senecio johnstonii Oliv. var. johnstonii is primarily used as an ornamental plant in rock gardens or hanging baskets. The stems can trail over the edge of a pot or wall, making a stunning display. In southern Africa, indigenous people used extracts from the plant to treat various ailments such as wounds, coughs, and colds.
Warning: This plant is toxic if ingested. It also causes skin irritation. Proper precautions should be taken while handling it, and it should be kept out of children and pets' reach.
Light requirements
The Senecio johnstonii Oliv. var. johnstonii is a plant that requires full sun to grow to its full potential. Consequently, it is advisable to grow the plant in an open area where it can receive direct sunlight. Failure to provide the plant with enough sunlight can cause its growth to be stunted.
Temperature requirements
The Senecio johnstonii Oliv. var. johnstonii is a plant that thrives in warm temperatures. The ideal minimum temperature for the plant is 60°F (15.6°C), while the maximum temperature is 90°F (32.2°C). At temperatures above 90°F (32.2°C), the plant may become stressed and may not grow as fast as it should. The plant can, however, withstand temperatures as low as 20°F (-6.7°C) for short periods.
Soil requirements
The Senecio johnstonii Oliv. var. johnstonii is not a picky plant when it comes to soil. It can grow in many soils as long as they are well-draining, and the pH is between 5.5 and 7.5. However, the plant does well in slightly acidic to neutral soils. Some of the suitable soil types for planting the Senecio johnstonii Oliv. var. johnstonii include loamy, sandy, and clayey soils. It is essential to note that the plant does not do well in waterlogged soils as they can cause root rot and eventually kill the plant.
Cultivation
The Senecio johnstonii Oliv. var. johnstonii plant requires a well-draining soil mix composed of a potting mix and perlite in a 2:1 ratio. It is best cultivated in a bright spot with indirect sunlight, at a temperature range of 15-20°C. It is also essential to ensure that the plant receives fresh air regularly.
Watering Needs
Senecio johnstonii Oliv. var. johnstonii requires moderate watering, offering the plant a moderate amount of water only when the top 1-2 inches of soil gets dry. Watering should be done carefully, allowing the water to penetrate deep into the soil. The plant pot must have a drainage hole to prevent waterlogging and root rot.
Fertilization
Senecio johnstonii Oliv. var. johnstonii should be fertilized once a month during the growing season with a balanced liquid fertilizer at half the dosage recommended on the package. Over-fertilizing should be avoided as it can lead to leaf burn, resulting in the wilting of the plant. In winter or dormant seasons, the plant only requires light feeding if any.
Pruning
As a slow grower, pruning of Senecio johnstonii Oliv. var. johnstonii is not necessary. However, pruning can be done to give the plant the desired shape. Prune only after the growing season has ended, and ensure to use sterilized scissors or pruning shears to avoid any plant diseases. Cut back overgrown stems or stems that are starting to wilt, ensuring not to over-prune as the plant will need adequate foliage to produce food for the growing season.
Propagation of Senecio johnstonii Oliv. var. johnstonii
Senecio johnstonii Oliv. var. johnstonii, commonly known as the Johnston's Senecio, is a perennial species that belongs to the family Asteraceae. It is native to tropical and subtropical regions of Africa, especially in Zimbabwe, Mozambique, and Malawi. Propagation of this plant is usually done through stem cuttings or seeds.
Propagation through Stem Cuttings
The stem cutting method of propagation is the easiest way to increase the number of Senecio johnstonii plants. It involves cutting a healthy stem from the parent plant and then planting it in a rooting medium. Here are the steps below:
- Choose a healthy stem from the parent plant that is about 6 inches long with several leaves attached.
- Using a sterilized sharp knife, cut the stem below a node (where the leaf is attached) at a 45-degree angle.
- Remove the lower leaves from the stem, leaving two or three leaves on the top part.
- Dip the cut end of the stem in rooting hormone to encourage root growth.
- Plant the cutting in a well-draining rooting medium and keep it moist. Place the pot in a warm and bright area that is out of direct sunlight.
- Avoid letting the soil dry out and mist the cutting often to prevent dehydration.
- After a few weeks, the stem cutting should have rooted and can be transplanted into a larger pot or directly into the garden.
Propagation through Seeds
Senecio johnstonii can also be propagated from seeds, but it requires more time and effort. The seeds should be planted during the growing season in a well-draining soil mixture. The steps involved in seed propagation are:
- Collect mature seeds from the parent plant and allow them to dry for a few days.
- Fill a small pot with a well-draining soil mixture and water it well.
- Plant the seeds in the soil and cover with a thin layer of soil.
- Water the pot and cover it with plastic wrap to retain moisture and warmth.
- Place the pot in a bright and warm area, but avoid direct sunlight.
- Germination should occur within 1-3 weeks, and the seedlings can be transplanted into larger pots or directly into the garden after they have grown a few sets of leaves.
Disease Management
Senecio johnstonii Oliv. var. johnstonii is generally resistant to most common plant diseases. However, like all plants, it is still susceptible to certain diseases. One of the most common diseases affecting this plant is powdery mildew.
Powdery mildew is a fungal disease that appears as a powdery white coating on the leaves and stems of the plant. To manage this disease, it is recommended to prune infected parts of the plant and use a fungicidal spray. Additionally, maintaining proper air circulation and avoiding overhead watering can also help prevent the spread of powdery mildew.
Another disease that can affect Senecio johnstonii Oliv. var. johnstonii is root rot. This disease occurs when the plant's roots become infected with a fungus or other pathogens. To prevent root rot, it is important to ensure that the plant is not overwatered and that the soil has proper drainage. If root rot does occur, remove the infected parts of the plant and consider repotting the plant in fresh soil.
Pest Management
Senecio johnstonii Oliv. var. johnstonii can also be susceptible to certain pests. One of the most common pests that can affect this plant is spider mites.
Spider mites are tiny pests that can be found on the undersides of leaves. They can cause plant leaves to turn yellow and can leave webbing on the plant. To manage spider mites, it is recommended to regularly inspect the plant and use an insecticidal spray if an infestation is found.
Another pest that can affect Senecio johnstonii Oliv. var. johnstonii is mealybugs. Mealybugs are small, white, fuzzy insects that can be found on the leaves and stems of the plant. They can cause stunted growth and can spread to other plants. To manage mealybugs, use a cotton swab dipped in alcohol to remove the insects from the plant. Alternatively, an insecticidal soap can also be used.
Overall, managing diseases and pests on Senecio johnstonii Oliv. var. johnstonii involves being proactive and vigilant in inspecting and caring for the plant. Proper cultural practices, such as adequate watering and good air circulation, can help prevent diseases and pests from taking hold. If an infestation or disease does occur, early intervention and treatment can help manage and minimize the damage.
