Great Blue Lobelia or blue cardinal flower, is a native perennial which typically grows in moist to wet locations along streams, sloughs, springs, swamps, meadows and in low wooded areas. This showy perennial is usually unbranched but may exhibit some branching. The erect, 2-3 ft., stems produce lavender-blue, tubular flowers crowded together on the upper stem. Showy, bright blue flowers are in the axils of leafy bracts and form an elongated cluster on a leafy stem. Each flower is split into two lips – the upper lip has two segments and the lower lip has three. A clump-forming perennial which features light to dark blue, tubular, 2-lipped flowers with the three lobes of the lower lip appearing more prominent than the two lobes of the upper lip. Flowers arise from the upper leaf axils forming a dense terminal raceme atop stiff, unbranched, leafy stalks. Finely-toothed, lance-shaped, light green leaves (to 5″ long).
This blue counterpart of the Cardinal Flower (Lobelia cardinalis), Great Blue Lobelia is a most desirable plant for woodland gardens especially since it blooms bright blue in late summer. Easily grown in rich, humusy, medium to wet soils in full sun to part shade. Needs constant moisture. Will tolerate full sun in cool, northern climates, but otherwise appreciates part shade. Divide clumps in spring as needed. May self-seed in optimum growing conditions, forming attractive colonies.
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