In cultivation,
L.
cardinalis requires rich, fairly deep soil which remains reliably moist—yet sufficiently aerated—all year-round; alternatively, it may be grown as an accent plant in or along ponds, fountains or other garden water features, with its pot positioned so it can always access water. If not planted in or around a water source,
L.
cardinalis tends to prefer for its roots to stay cool, something achieved when grown in dappled sun or part shade. The
cultivar 'Queen Victoria' has gained the
Royal Horticultural Society's
Award of Garden Merit. This plant is easily propagated by seed or by dividing-out the young plants, which are seen forming around the older, more mature plants each year. Although the plant is generally considered a perennial, they may be short-lived, or behave more as a "long-term annual". Within the
freshwater planted aquarium and
aquascaping hobbies, the species is used somewhat frequently. At least one new variety has been developed and is available commercially,
Lobelia cardinalis 'Mini', with small and compact green leaves. ==Medicinal and other uses==