Great Blue Lobelia - Lobelia siphilitica Hardy Planting Zones- 3-9 Sun or Shade – Full sun to part shade Mature Height - 24-36" Mature Width- 12-18" Bloom Season – Summer (July to September) Gardener Status- Beginner
The downy lobelia, one of many in the beautiful lobelia family, is a late summer blooming perennial with irregularly shaped purple or blue flowers with white centers. Most people know the downy lobelia by the fact that the flowers grow sideways from the main stalk and by their beautiful colors. The upper lip of each flower has two lobes, the lower has three. The elliptical leaves alternate along the stem directly without a petiole, intertwining with the flowers, and can be recognized by the small, irregularly spaced teeth and hairy underside. Normally they reach 5 inches long and 1.5 inches wide. The downy lobelia’s fruit is small and seedy, and it propagates via those seeds into clumps when it grows in the wild. Bees are the main pollinators of the downy lobelia, and it can be found in gardens throughout the lower 48 states. Its main habitat stretches along open roadways and forests from the northern third of Florida up to New Jersey and westward towards Texas and Arkansas. As a landscape flower, it is very unique and showy and adaptable to a variety of climate and soil conditions. Usually it prefers moist, sandy and open ground but also does well in swamps, meadows, and woodlands. When landscaping, keep the soil watered because they prefer consistent moisture. They do best in the sun to partial shade, but can grow to as much as 3-5 feet in some cases so keep open spaces around them when doing your landscaping. Each winter it dies back into the ground but it will return in the early spring with new basil leaves along the stems before blooming in late summer.