Overview of Lobelia bifida Thunb.
Lobelia bifida Thunb. is a flowering plant found in Southern Africa, mostly in the Eastern Cape and KwaZulu-Natal provinces. The plant belongs to the family Campanulaceae and is known by various common names such as KwaZulu Natal lobelia, mountain lobelia, and Milweni.
The General Appearance of Lobelia bifida Thunb.
Lobelia bifida Thunb. grows up to 1m tall and has a shrubby habit. The plant has narrow, pointed, and hairy leaves that are usually about 50mm long. The flowers of the plant occur in clusters at the end of the branches, and they range in color from pale blue, white, to purple. Each flower is about 8mm long and has five thin petals fused at the base.
Uses of Lobelia bifida Thunb.
Lobelia bifida Thunb. has a variety of uses. The plant is used in traditional medicine to treat ailments such as cough, colds, headaches, and fever. Parts of the plant are used as a tea and powder to treat respiratory problems and inflammation. Additionally, the plant is a source of food for animals, especially baboons, and it is sometimes used as an ornamental plant in gardens.
Light Requirements
The Lobelia bifida Thunb. plant requires bright, indirect light to grow correctly. It thrives in partial sunlight or a shaded area with enough light penetration. Full exposure to the sun can damage the plant, and it should be avoided.
Temperature Requirements
The plant grows well in a wide range of temperatures. It can tolerate cold and hot temperatures as long as they do not fall below 10? or rise above 35?. The optimum temperature range for the plant growth is 15? to 25?.
Soil Requirements
The soil requirements for Lobelia bifida Thunb. are quite specific as it prefers well-drained, moist, and fertile soils. The ideal soil pH ranges from 5.0 - 6.0 for the plant to thrive. The soil must also be rich in organic matter, such as compost or leaf mold. It should not be heavy, clayey, or compacted as it may limit proper root growth.
Cultivation Methods
Lobelia bifida Thunb. is a low-growing herbaceous plant that is ideal for rock gardens, ground covers, and containers. It is native to Japan and requires warm temperatures to thrive. When cultivating, choose a site that provides full sun to partial shade.
It is advisable to plant Lobelia bifida Thunb. in well-drained soil that has been amended with organic matter. The ideal soil pH range is 6.1 to 7.8. Planting should be done during spring or early summer when the soil has warmed up.
Watering Needs
During the growing season, Lobelia bifida Thunb. requires a consistent supply of moisture to do well. Water the plant when the top inch of soil is dry. When watering, avoid wetting the foliage and flowers as this can lead to fungal infections. It is also best to water in the morning so that the plant can dry off before nightfall.
Fertilization
To encourage Lobelia bifida Thunb. to produce more flowers, it is advisable to fertilize it using a balanced fertilizer. Use a water-soluble fertilizer once a month during the growing season. Avoid over-fertilization as this can lead to excessive foliage growth at the expense of flowers.
Pruning
Pruning is essential to maintain the vigor and shape of Lobelia bifida Thunb. Deadheading spent flowers is an essential part of pruning as it prevents the plant from self-seeding and promote the growth of new blooms. Cut back the plant by one-third after it has finished blooming to encourage bushier growth. In colder regions, cut the plant back to the ground in late fall.
Propagation of Lobelia bifida Thunb.
Lobelia bifida Thunb. can be propagated through various methods including:
Seed Propagation
The plant produces tiny seeds that can be collected from the existing plant and sown in potting mix during winter or early spring. The seeds are quite small, and it is important to ensure that they are sown as thinly and evenly as possible for proper germination. The seeds can be lightly pressed into the soil surface or covered with a light sprinkling of sand or vermiculite to provide darkness which aids germination. The pots or trays should then be watered to prevent the seed from drying out. Germination usually occurs within 7-10 days, and the young seedlings can be transplanted into individual containers once they reach a suitable size.
Cuttings Propagation
Lobelia bifida Thunb. can also be propagated through cuttings. Softwood cuttings are taken from the stem tips of the plant and rooted in a rooting hormone. The cuttings should be taken early in the growing season as soon as they are long enough to ensure that they root quickly. The cuttings can be potted into individual containers filled with potting mix, and watered regularly to ensure that they root and grow fully. After about 2-3 weeks, the cuttings should have rooted, and they can be transplanted into larger containers.
Division Propagation
The plant can also be propagated through division. This involves dividing the existing plant into several smaller plants each with separate roots. This method is ideal for mature plants that have become too large for their pots or garden beds. The plant should be carefully removed from the soil, and the roots gently teased apart using a sharp knife. The separated plants can then be potted in individual containers, watered thoroughly and kept in a shaded area until they re-establish.
Disease Management
Lobelia bifida Thunb. is typically a hardy plant with minimal disease issues. However, the following are some of the common diseases which may affect this plant:
Crown Rot
Crown rot is caused by a fungal infection and can attack lobelia at any stage of growth. Symptoms include yellowing leaves and a wilting crown. Once the crown becomes infected, there is no cure. The plant should be removed and destroyed, and the soil in the area should be sterilized to prevent further spread of the fungus. To prevent crown rot, avoid over-watering and ensure proper soil drainage.
Leaf Spot
Leaf spot is caused by a fungal infection that results in small, dark spots on the leaves. These spots will eventually spread and merge, causing the leaves to die and fall off. To prevent leaf spot, provide adequate air circulation around the plant, avoid over-watering, and remove any infected leaves as soon as they appear.
Pest Management
Lobelia bifida Thunb. is also susceptible to insect infestations. The following are some common pests that may affect this plant:
Aphids
Aphids are small insects that feed on the sap of the plant. They can cause stunted growth and distortion of leaves. To prevent aphids, regularly inspect the plant for signs of infestation, and use insecticidal soap or a strong stream of water to remove them. Additionally, attracting natural predators such as ladybugs can help control aphid populations.
Spider Mites
Spider mites are tiny arachnids that can cause brownish-yellow spots on leaves and webs on the plant. To prevent spider mites, keep the plant well-watered, and regularly spray the plant with water to increase humidity. Insecticidal soap or horticultural oil can also help control spider mites on the plant. Additionally, natural predators such as ladybugs or lacewings can help control this pest population.
