|PELARGONIUM species - Geranium|
Geraniaceae; native to South Africa.
Germination: Seed may be scarified before shipping. Seeds of P. x hortorum are best sown indoors, 12-16 weeks before last frost, at a temperature of 70-75°. Expect germination in 5-15 days. Seeds of the scented geraniums are best sown indoors, 12 weeks before last frost, at alternating temperatures of 68 and 86°. Expect germination in 20-50 days. It is not recommended to sow either of these types outdoors.
Growth: Transplant when there are at least two sets of true leaves. Grow on at 70-75°days/65-70° nights. Plant out in full sun to afternoon shade in a neutral to alkaline, rich, well-drained soil. Feed well, water plentifully, and deadhead constantly. For conservatory culture: site in full sun, provide 50-55° nights and good air circulation, make sure that the soil is slightly acidic, and allow plants to dry out between waterings. Keep plants pot bound and while plants are in active growth, feed twice monthly. Pelargonium x hortorum may be stored dormant over the winter, however, this practice is not recommended as plants become woody and less productive the following year.
Appearance and Use: Primarily grown as a bedding and container plant (planters, window boxes, hanging baskets), it is also useful as filler in the border and grown indoors in the house or conservatory. Pelargonium x hortorum, Zonal Geranium, is one plant that everyone knows by name. Plants grow 15-24 inches tall and produce 5 inch heads of pink, salmon, red, and white. Leaves are heart shaped from 3-5 inches across and have scalloped margins. They often have a darker green zone in the center of them, thus the common name.
NASA Seeds in Space
"Plants vary in their heat stress tolerance, not only from species to species, but also from cultivar to cultivar. In addition, unusual seasons-fewer or more hot days than normal-will invariably affect results in your garden, as will extremely dry or humid conditions," Dr. H. Marc Cathey, with Linda Bellamy, Heat-zone Gardening, How to choose plants that thrive in your region’s warmest weather.