Overview of Lobelia depressa auct. var. depressa
Lobelia depressa auct. var. depressa is a species of flowering plant in the family Campanulaceae. It is a perennial herbaceous plant that is native to parts of North America and found in various habitats such as wetlands, prairies, and woodlands.
Common Names
Lobelia depressa auct. var. depressa is commonly known as bog lobelia, trailing lobelia, and wild blue lobelia.
Uses
The bog lobelia has a long history of medicinal use by North American indigenous communities. Its extracts were used to treat respiratory conditions such as asthma, bronchitis, and pneumonia, and it was also used to induce vomiting as a remedy for various ailments. Today, bog lobelia is still used in herbal medicine for its respiratory benefits. It is also used in horticulture as an attractive ground cover or in container plantings due to its cascading growth habit and vibrant blue-purple blooms.
General Appearance
Lobelia depressa auct. var. depressa is a low-growing plant that typically reaches a height of only 6-12 inches and a spread of 12-18 inches. Its stems are thin, wiry, and trailing, with small, oval-shaped leaves that grow alternately along the stems. The plant produces numerous small flowers in intense blue-purple hues that bloom from mid-summer to early fall. The flowers grow in clusters along the stems and attract pollinators such as bees and hummingbirds.
Light requirements:
The Lobelia depressa auct. var. depressa plant thrives under partially shaded conditions. Full sunlight exposure can damage the plant's leaves and cause it to wilt. Therefore, it is best to grow it in areas where it can receive filtered light or early morning or late afternoon sunlight. Ideal growing locations would be under trees, near fences, or walls that can partially block out direct sunlight.
Temperature requirements:
The Lobelia depressa auct. var. depressa plant is native to sub-alpine and alpine regions. It can withstand low temperatures and frost and will continue to grow well in colder weather. The ideal growing temperature range for Lobelia depressa auct. var. depressa is between 6°C to 18°C (43°F to 64°F). It is important to note that this plant cannot tolerate extreme heat and hot, dry weather. Therefore, if you live in an area with high heat and humidity, it is recommended to grow Lobelia depressa auct. var. depressa indoors or in a cooler and shadier environment.
Soil requirements:
The Lobelia depressa auct. var. depressa plant prefers well-draining soil rich in organic matter. A soil pH level between 5.5 to 6.2 is ideal for this plant. It cannot tolerate waterlogged soil, and therefore, proper drainage is crucial. A sandy loam or a mixture of peat moss, sand, and perlite is the best soil mixture for Lobelia depressa auct. var. depressa growth. It is also important to ensure that the soil is consistently moist and not allowed to dry out.
Cultivation
Lobelia depressa auct. var. depressa is a low-growing plant that is generally easy to grow. It can be cultivated in various soil types, including sandy soils, well-draining loam soils, and clay soils. However, this plant prefers a soil that is rich in organic matter and slightly acidic to neutral pH levels.
It is best grown in partial to full shade areas, and it is tolerant of frost and can withstand temperatures as low as -15°C. The plant should be planted in the early spring to allow ample time for it to develop its roots and establish itself before the hot summer months.
Watering Needs
Lobelia depressa auct. var. depressa needs to be kept moist but not waterlogged. It is essential to avoid overwatering the plant as it can cause root rot. During the hot and dry summer months, it is recommended to water the plant frequently to keep the soil consistently moist.
The best method to water this plant is using a soaker hose or a drip irrigation system. This method allows for a slow and steady stream of water to be delivered directly to the roots, ensuring efficient distribution without wastage.
Fertilization
For Lobelia depressa auct. var. depressa to thrive, it needs to be fed with a slow-release fertilizer. It is recommended to apply a balanced fertilizer, such as a 10-10-10 or 20-20-20 formulation, during the early spring. The fertilizer should then be reapplied every four to six weeks throughout the growing season.
It is essential to avoid overfeeding the plant as it can lead to excessive growth and fewer flowers. It is also crucial to follow the manufacturer's instructions when applying fertilizers to avoid harming the plant.
Pruning
Lobelia depressa auct. var. depressa requires minimal pruning. However, it is recommended to deadhead the plant regularly to remove any faded flowers. This process encourages the plant to redirect its energy into producing new flowers.
If the plant becomes too leggy or overgrown, it can be trimmed back to promote new growth and maintain a desired shape. Trimming should be done in the early spring before the growing season begins. Avoid pruning during the flowering season as it can result in a reduction of blooms.
Propagation of Lobelia depressa auct. var. depressa
Propagation of Lobelia depressa auct. var. depressa is primarily done by vegetative means. This is because the plant does not produce a lot of seeds and can be difficult to grow from them.
Stem cuttings
Stem cuttings are the easiest method of propagating Lobelia depressa auct. var. depressa. It involves using a sharp and clean pair of scissors or pruning shears to cut a section of the plant's stem. Make sure that the cutting has several nodes and is about 2-3 inches in length. Remove the leaves from the bottom end of the stem and dip it in rooting hormone. Plant the cutting in a well-draining potting medium and place it in a warm, bright spot. Keep the soil moist but not soggy and the cutting should root within a few weeks.
Division
Another method of propagating Lobelia depressa auct. var. depressa is through division. This involves carefully digging up the plant and separating it into several smaller sections, each with its own set of roots. Make sure each division has enough leaves and roots to survive on its own. Plant each division in its own pot or in the ground, where it will grow into a new plant.
Grafting
Grafting is a more advanced propagation technique that involves combining the stem of Lobelia depressa auct. var. depressa with the rootstock of another plant species. This method is typically used when a grower wants to produce a specific type of plant that cannot be easily grown from seed or stem cuttings. Grafting should be done in early spring when the plant is actively growing. It is important to make sure that the cambium layers of both the stem and rootstock match up before binding them together and allowing them to grow as one plant.
Disease Management
One common disease that affects Lobelia depressa is downy mildew, caused by a fungus-like organism called Peronospora lobeliae. The symptoms of this disease include yellowing of the leaves, wilting, and the presence of a downy white or grayish mold on the undersides of leaves. To manage downy mildew, it is recommended to remove any infected plant parts and improve air circulation around the plant.
Another disease that can affect Lobelia depressa is fungal leaf spot. This disease is caused by different types of fungi and is characterized by circular or irregular brown spots on the leaves. To manage fungal leaf spot, it is recommended to remove any infected plant parts and avoid overhead watering.
Pest Management
One common pest that affects Lobelia depressa is aphids. These small insects can cause distorted growth, yellowing of leaves, and a sticky substance on plant surfaces. To manage aphids, it is recommended to remove them manually or to use insecticidal soap or horticultural oils.
Another pest that can affect Lobelia depressa is slugs. These slimy creatures can cause irregular holes in the leaves and leave behind a silvery trail. To manage slugs, it is recommended to remove any hiding places or debris in the surrounding area and to use slug bait or traps.
