Overview
Lobelia pygmaea Thunb. is a small perennial herbaceous plant that belongs to the family of Campanulaceae. This plant is native to South Africa and was first described by the botanist Carl Peter Thunberg in 1794. It has several common names such as Dwarf Lobelia, Southern Blue Lobelia, and Baviaanskloof Lobelia.
Appearance
Lobelia pygmaea Thunb. is a small, creeping plant that grows up to 20 cm tall and 30 cm in diameter. Its leaves are ovate to lanceolate, up to 3.5 cm long and 1.5 cm wide, with a slightly serrated margin, and have a pale green color. The plant produces small, light blue flowers that are tubular and up to 1 cm long. These flowers grow in clusters on top of short stems above the foliage.
Uses
Lobelia pygmaea Thunb. is often used as an ornamental plant due to its delicate and attractive appearance. It is a popular choice for rock gardens, fairy gardens, and as a groundcover in sunny spots with well-draining soil. In addition to its aesthetic value, the plant has been used in traditional medicine for its antimicrobial properties. The plant's extract has also been used as a natural remedy for respiratory problems such as coughs, colds, and asthma.
Cultivation
Lobelia pygmaea Thunb. thrives in well-draining soil with a neutral to slightly acidic pH and full sun to partial shade. The plant prefers moderate watering and does not tolerate overwatering or waterlogged soil. It is a hardy plant that can tolerate light frost but prefers a warmer climate. Lobelia pygmaea Thunb. can be propagated through seeds or cuttings and is relatively low maintenance once established.
Light conditions
Lobelia pygmaea Thunb. requires bright and indirect sunlight to flourish. The plant can tolerate partial shade, but it needs plenty of light to grow and bloom. Exposure to direct sunlight may scorch the leaves, so it is advisable to provide some shade during the hottest part of the day.
Temperature requirements
The plant prefers temperate climates with mild to warm temperatures ranging from 15 to 25 °C. Although it can tolerate some fluctuation in temperature, the Lobelia pygmaea Thunb. cannot survive extreme cold or hot temperatures. Therefore, it is best to keep the plant in a warm and sheltered location, away from drafts and frosty nights.
Soil conditions
Lobelia pygmaea Thunb. requires well-draining and fertile soil with a pH level of 6 to 7.5. The plant prefers sandy or loamy soil that is rich in organic matter. It is important to keep the soil consistently moist, but not waterlogged, as the Lobelia pygmaea Thunb. cannot tolerate drought or waterlogged soil. Adding organic compost or fertilizer can improve the soil quality and promote healthier growth and blooming.
Cultivation methods for Lobelia pygmaea Thunb.
Lobelia pygmaea Thunb. is a low-growing, perennials species that prefers moist well-drained soils with partial shade and protection from intense afternoon sun. It grows in USDA hardiness zones 3 through 7, where winter temperatures rarely drop below -40° F. The best location for cultivating Lobelia pygmaea is in a rock garden or edging a border, where it can create dense ground cover.
Watering needs for Lobelia pygmaea Thunb.
This plant requires moderate watering, especially during prolonged droughts, dry spells, or hot summer months. Watering should be done at the base of the plant or via a drip irrigation system to avoid wetting the foliage as Lobelia is susceptible to fungal diseases.
Fertilization for Lobelia pygmaea Thunb.
Lobelia pygmaea Thunb. is not an overly demanding plant, but it will benefit from a yearly dose of organic fertilizers like compost or well-rotted manure. Fertilizers with too much nitrogen should be avoided as it favors foliar growth over flowering.
Pruning for Lobelia pygmaea Thunb.
Prune spent flowers regularly to encourage the plants to produce a continuous flush of blooms. This should be done by cutting back the entire flowering stalk after blooming and shear small areas of older growth to maintain the desired size. The best time to prune is in early spring while the plant is still in its dormant phase.
Propagation of Lobelia pygmaea Thunb.
Lobelia pygmaea Thunb., commonly known as Pygmy Lobelia, is a beautiful plant native to South Africa. It has small, delicate flowers that bloom in a range of colors, including blue, pink, and white. The plant can be propagated through various methods to propagate new plants.
Seed Propagation
The most common method of propagating Lobelia pygmaea Thunb. is through seeds. You can collect seeds from mature plants or purchase them from a reputable nursery. Here is how you can propagate new plants from seeds:
- Sow the seeds in a seedling mix in a container, preferably in spring.
- Lightly cover the seeds with the mix and water gently.
- Place the container in a warm and bright area of your house or greenhouse.
- Keep the soil moist by misting it regularly.
- The seedlings will germinate in a few weeks. Once they have grown to a sufficient size, transfer them to individual pots.
Cuttings Propagation
You can also propagate Lobelia pygmaea Thunb. through cuttings. This method works well if you want to produce new plants that are identical to the parent plant. Follow these simple steps:
- Choose a healthy, non-flowering stem from the parent plant and cut it with a clean, sharp pair of scissors.
- Make sure the cutting is around 8 to 10 cm long and has at least two pairs of leaves.
- Dip the stem in rooting hormone to encourage root growth.
- Plant the cutting in a well-draining soil mix and water gently.
- Place the container in a warm and bright area, but not in direct sunlight.
- Keep the soil moist by misting it regularly.
- The cutting will develop roots in a few weeks. Once the roots have formed, transfer the new plant to an individual pot.
Propagation of Lobelia pygmaea Thunb. is quite simple and can be done easily with the right knowledge and technique.
Disease Management
Lobelia pygmaea Thunb., also known as the dwarf Lobelia, is susceptible to a few infectious diseases that can limit its growth and threaten its overall health. The following are common diseases that might affect this plant and ways to manage them:
Crown and Root Rot
Crown and root rot is caused by soil-borne fungi that thrive in overwatered or poorly drained soils. Symptoms of this disease include yellowing leaves, wilting, and stunted growth. To manage this disease, it’s essential to avoid overwatering and ensure proper drainage. If the disease is severe, you can try applying fungicides such as copper-based ones to the soil or using soil drenches.
Mildew
Mildew is a fungal disease that attacks the leaves of Lobelia pygmaea Thunb. It appears as a grayish-white powdery substance on the leaves, and under severe conditions, may lead to leaf drop and stunted growth. To manage this disease, try planting the Lobelia pygmaea Thunb. in a location with adequate sunlight exposure and proper air circulation. You can also apply fungicides to infected areas.
Pest Management
Lobelia pygmaea Thunb. may also attract some pests that can damage it. The following are common pests that might attack this plant and ways to manage them:
Spider Mites
Spider mites are common pests that may feed on the leaves of Lobelia pygmaea Thunb. They are tiny, almost invisible, and can cause leaves to appear speckled or distorted. To manage spider mites, use insecticidal soaps, insecticides, or remove infested plants.
Slugs and Snails
Slugs and snails may feed on the Lobelia pygmaea Thunb. plant, especially during moist conditions. They leave large holes on leaves and may cause stunted growth. To manage these pests, try handpicking them and removing them from the area surrounding the plant. You can also sprinkle diatomaceous earth on plants, or use beer traps to capture them.
Whiteflies
Whiteflies are sap-sucking insects that can cause severe damage to Lobelia pygmaea Thunb. plants. They may cause the leaves to yellow, stunt growth, or cause significant leaf drop. To manage the pests, use yellow sticky traps or apply insecticides, especially during the early stages of infestation.
