Blue BellText Box: BLUE BELL (Ruellia brittoniana) Small, blue bell flowers. Short, green linear foliage. Can grow 18 to 30 inches. Prefers moist soil, and does not like being in more than 1/2 inch of water. Bog plant Semi hardy. Weather permitting we ship the tropical marginal and bog plants April through September. OUR MARGINAL AND BOG PLANTS ARE EITHER IN 2 INCH POTS OR BAREROOT Fuller plants available in 4 inch pots, must purchase 3 minimum Tropical marginal and bog plants will not survive the cold temperatures, if you live in zone 7 and below you might consider them to be annuals or bring them indoors in the winter.