Lobelia siphilitica, commonly known as the Great Blue Lobelia or Blue Cardinal Flower, is a captivating native perennial wildflower found in eastern North America. This striking plant typically grows to heights of 2 to 3 feet (60 to 90 cm) and is renowned for its dramatic display of vibrant blue, tubular flowers that cluster on tall spikes. These blossoms bear a striking resemblance to those of the cardinal flower but are a distinctive shade of blue. The lance-shaped leaves are deep green and form a lush backdrop to the brilliant blooms. Lobelia siphilitica thrives in moist to wet soils, often found near streams, ponds, and other damp areas, making it an excellent choice for rain gardens and waterside plantings. This lobelia species attracts pollinators like bees and hummingbirds with its nectar-rich flowers and adds a burst of color and wildlife interest to native plant gardens, particularly in late summer when it comes into full bloom. Zones 5-9.
Germination
Germinating Lobelia siphilitica seeds can be a rewarding but somewhat challenging process. To break their dormancy, stratify the seeds by placing them in a moist paper towel or peat moss and then seal them in a plastic bag or container. Refrigerate for 6-8 weeks to mimic winter conditions. After stratification, sow the seeds in a well-draining seed-starting mix in a seed tray or small pots. Lightly press the seeds onto the surface of the soil, as they require light for germination, and do not bury them. Provide indirect sunlight or use grow lights to maintain a temperature around 70-75°F (21-24°C). Keep the soil consistently moist but not waterlogged, using a fine mist to water the seeds to avoid dislodging them. Germination can be slow, taking several weeks to a few months. Once the seedlings have developed several true leaves, transplant them into individual pots or into the garden bed once the risk of frost has passed. Handle the delicate seedlings with care, and provide well-drained soil and partial shade in the garden for optimal growth. Be patient, as Lobelia siphilitica seeds may require some time and attention to achieve successful germination.
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