Overview
Lobelia elongata Small, commonly known as longflower lobelia, is a flowering plant species that belongs to the Campanulaceae family. This plant is native to the southeastern United States, particularly in the states of Georgia, Alabama, Florida, and Louisiana. Lobelia elongata can be found growing in wet meadows, swamps, along stream banks, and in other damp and sunny environments.General appearance
Lobelia elongata is a perennial herb that can reach a height of 1.5 meters (5 feet). This plant has lance-shaped leaves that are arranged oppositely along the stem. The leaves are 6 to 12 cm long, and may be hairy or smooth on the surface. The stem of the plant is reddish-brown, often with a purplish hue, and is also hairy. Longflower lobelia produces a spike-like inflorescence that can be up to 30 cm long. The flowers of this plant are trumpet-shaped and are typically a shade of blue or lavender, though occasionally white.Common names
Apart from longflower lobelia, Lobelia elongata is sometimes called long-tube lobelia, tall lobelia, and wild tobacco. The plant is given this last common name due to the use of its leaves by Native American tribes for medicinal purposes.Uses
Lobelia elongata has a long history of medicinal use among Indigenous communities. The plant contains alkaloids that can be toxic when consumed in large quantities, but also have useful medicinal properties when used appropriately. The fresh or dried leaves of the plant have been used to induce vomiting, as a diuretic, and in the treatment of respiratory ailments such as asthma and bronchitis. Today, the plant is primarily grown as an ornamental, and is sometimes used in wildflower gardens. However, its historic medicinal uses continue to be studied by researchers.Light Conditions
Lobelia elongata typically grows best in full sun to partial shade conditions. It thrives under bright and direct sunlight but can tolerate some shade. However, if grown in too much shade, the plant tends to bloom less and become leggy. Therefore, providing adequate sunlight is important for proper growth and flowering of this plant.
Temperature Requirements
Lobelia elongata prefers moderate temperatures, and it grows well in USDA hardiness zones 4 to 9. The plant requires a temperature between 60 to 75°F (15 to 24°C) for germination and growth. However, it can tolerate a minimum temperature of 55°F (13°C). In excessively hot conditions, the plant can wilt, and its growth slows down. Therefore, it is essential to ensure the plant is grown in a suitable temperature range.
Soil Requirements
Lobelia elongata grows well in well-drained and loamy soil. The plant prefers soil that is rich in organic matter and slightly acidic to neutral (pH 5.5-7.0). The plant can tolerate a range of soil textures, from sand to clay, but it needs to be well-drained and not waterlogged. To ensure proper growth, the soil must be kept moist, and the plant needs regular watering in dry conditions. Additionally, applying a balanced fertilizer in spring can help promote better growth and flowering.
Cultivation
Lobelia elongata Small, also known as longleaf lobelia, is a native plant species to the southeastern United States. It prefers to grow in wetlands, marshes, and along streambanks. To cultivate this plant, it is significant to provide moist soil conditions with good drainage.
The best location to plant Lobelia elongata is in partial to full shade. The plant can tolerate direct sunlight, but it performs ideally in high shade or filtered light. Preparing the soil before planting is essential. The soil mix should contain a high percentage of organic matter, such as peat moss, compost, or bark, mixed with sand or perlite, and loam. The soil pH should range between slightly acidic to neutral.
Watering Needs
Lobelia elongata needs consistent moisture, although it is drought-tolerant. Water the plant once a week, depending on the soil's moisture content. If the soil dries too much, the plant may wilt and die. Avoid overwatering the plant, as it can cause root rot.
Fertilization
Fertilizing the Lobelia elongata should be done once a month during the growing season. Use a balanced fertilizer, such as an 8-8-8 or 10-10-10 blend, following the instructions on the label. Avoid over-fertilizing, as it can cause the plant to grow too fast and not develop properly.
Pruning
Lobelia elongata does not need pruning as it naturally grows with an upright habit. However, pinching the tops of the plant when young encourages bushier growth. Deadheading spent blooms during the blooming period will promote new growth and extend the flowering time. Cut back the plant in late fall or early spring to rejuvenate growth for the following season.
Propagation of Lobelia elongata Small
Lobelia elongata Small, also known as long lobelia or longflower lobelia, is a perennial herbaceous plant native to the United States. In order to propagate this plant, there are a few methods one can employ:
Seeds
The most common method of propagating lobelia elongata is by seeds. Seeds should be planted in a well-draining soil mix with a pH of 5.5-6.5. Ideally, the seeds should be started indoors in early spring and then transplanted outside after the last frost date. Sow the seeds lightly on top of the soil and water gently, taking care not to wash them away. Keep the soil moist but not water-logged and the seeds should germinate in 7-10 days.
Stem Cuttings
Stem cuttings are another method of propagating lobelia elongata. Take a cutting from the plant in the spring during the active growing season. The cutting should be 3-4 inches in length and taken from a healthy stem, avoiding any woody or diseased sections. Remove the leaves from the bottom half of the stem and dip the cut end in rooting hormone. Plant the cutting in well-draining soil mix and cover with a plastic bag or propagation dome to keep moisture in. Keep the soil moist and the cutting should develop roots in 2-3 weeks.
Division
Finally, lobelia elongata can also be propagated by division. This method is best done in the spring before new growth begins. Carefully dig up the plant and divide it into smaller sections, ensuring that each new section has a healthy root system and several stems. Transplant the new sections into fresh soil mix and water well.
Disease Management
Lobelia elongata Small is susceptible to a few diseases that can be detrimental to the health and growth of the plant. Here are some common diseases that might affect the plant:
- Botrytis blight: This fungal disease presents as gray mold on the leaves and stems of the plant. To manage this disease, remove the infected parts of the plant and apply a fungicide to prevent further spread.
- Root rot: This disease is caused by overwatering and poor drainage. To manage root rot, reduce watering and improve soil drainage. If the plant is severely affected, replant it in fresh, well-draining soil.
- Verticillium wilt: This soil-borne fungal disease causes the leaves to wilt and turn yellow or brown. Unfortunately, there is no cure for verticillium wilt, so the infected plant should be removed and disposed of to prevent the spread of the disease.
Pest Management
Aside from diseases, Lobelia elongata Small is also prone to pest infestations that can cause damage to the plant. Here are some of the common pests that might affect the plant and how to manage them:
- Aphids: These small insects suck the sap from the plant, causing stunted growth and yellowing leaves. To manage aphids, spray the plant with a strong stream of water or apply insecticidal soap.
- Caterpillars: These larvae of moths and butterflies can strip the plant of its leaves. To manage caterpillars, pick them off the plant by hand or apply an insecticide that specifically targets caterpillars.
- Spider mites: These tiny pests feed on the plant's sap and can cause discoloration and leaf drop. To manage spider mites, spray the plant with a strong stream of water or apply insecticidal soap.
