DESCRIPTION: These are tender annual or perennial plants native of South America. They have straight stems, 1 to 2½ feet high. In the summer and early winter, small, terminal clusters of flowers that range in color from pale blue to violet, grow from the stems. In the summer, they can be grown outdoors and taken into a 45- to 50-degree greenhouse in the winter.
POTTING: Browallias are usually grown as annuals and are raised from seeds or cuttings in March. In the middle of May, they can be planted outside in full sun, 9 inches apart. They can also be planted in 5-inch pots, filled with equal parts of loam and leaf mold with a bit of sand added, to bloom in the greenhouse or window garden. When the flower buds show, those in pots should be watered with dilute liquid fertilizer weekly.
PROPAGATION: Cuttings, made from the current year's shoots, are taken in September or March and inserted in a propagating case in a warm greenhouse. Seeds can be sown in March in a greenhouse that has a 50- to 55-degree temperature. Plant them in pots of fine, sandy soil and lightly cover them. When they're an inch or so high, they're potted individually in small pots filled with the compost described in potting, or they can be set 2 to 3 inches apart in flats filled with similar soil. Keep them in a greenhouse or cold frame until mid-May, when they may be planted outside in full sun, 9 inches apart. Seeds that are sown in June will bloom during the winter in a greenhouse that has a 45- to 50-degree temperature.
VARIETIES: B. speciosa (major) (semi-shrubby perennial, large blue flowers with white throats); B. americana (elata) (an annual, pale blue to violet flowers); B. viscosa (an annual with bluish flowers).