Lobelia was introduced more than 200 years ago from the region around the Cape of Good Hope. The original wild forms of lobelia have been bred to bloom more profusely. There are both trailing varieties, with billowing masses of blossoms, and more compact bedding types, seldom exceeding 6 inches in height.
The 1/2- to 3/4-inch-wide flowers, borne along each stem, are blue on the common varieties, but white and carmine types have also been developed.
Lobelia is prized for window boxes, hanging baskets, planters, and ground covers. Although the plants do best in full sun and moist, rich soil where summers are cool, they will grow surprisingly well in hot areas if given partial shade.
Lobelia is not sown directly in the garden because it does not begin to flower until two months after seed is planted. Start the seeds indoors 10 to 12 weeks before the last frost is due; since the seeds are very small, plant them on top of finely prepared soil without covering them. Most nurseries and garden supply stores offer started plants already in bloom.
Transplant after all danger of frost is past, spacing them 4 to 6 inches apart. Remove flower spikes after blooming to produce further growth. 'Rosamund' is the pictured cultivar.
