Lobelia siphilitica

At times, blue lobelia’s stately blooms appear rather formal for their rough-and-ready guest, the bumble bee. Each flower possesses a blue-and-white striped space into which the bees crawl when seeking nectar. It’s amusing to watch the bumbles at work, rummaging for nectar in blooms that seem much too dainty for them, their hind portions protruding conspicuously from the flower openings. Although bumble bees are the primary pollinators of blue lobelia, the plant attracts a variety of bees of varying sizes, as well as butterflies.

A plant of woodland borders, especially along rivers, blue lobelia is perfectly suited for partially shaded wet spots in the garden. The plant will also do well in full sun, as long as the soil isn’t too dry. A layer of leaf mulch can help to conserve soil moisture for this and other plants. Blue lobelia is a short-lived species and is not very competitive. In order to keep it coming back, allow for some bare soil next to the plant where it can deposit its seeds.

As a point of interest regarding local adaptation, some research suggests that naturally occurring blue lobelia populations have special relations with the soil fungi in their immediate area. The fungi help the plant roots absorb phosphorus, an important nutrient for growth and metabolism.

References: 1,2,3,4,5,6.

Photos by Julie Slater.