Growing these sun lovers; keeping them over the winter. Geraniums (pelargoniums) thrive in most garden soils. Their showy blossoms range from bright red to pink to white. The variously shaped leaves of some are delightfully scented. In a frost-free climate, they can grow outdoors permanently.
In other areas, after the last frost, set out established plants in full sun in flower beds, in window boxes, or in planters, spacing them 8 to 15 inches apart. (Or simply sink the pots into the soil.) Feed monthly with a fertilizer low in nitrogen; pinch back new growth to keep plants bushy. Keep flowers coming by removing old ones as they fade. Let the soil get slightly dry between waterings.
To keep plants over the winter, bring them indoors well before the first frost. Cut them about halfway back, pot them in the smallest pot that will accommodate their roots, and place them on a sunny windowsill. They do best in low humidity and cool temperatures (65°F to 70°F by day, 5°F to 10°F lower at night). Cut the plants back again when new shoots are 4 to 5 inches long.
Grow new geraniums from 3 to 4 inch tip cuttings taken in August or September. Remove all but three healthy leaves from each and insert the stems in moist sand or perlite. Cover with a clear plastic bag in which you have poked a few holes. After they root, plant them singly in small pots and keep them in a cool, sunny window. Repot in medium-size containers in January or February.