Geranium ' Mustang' (Pelargonium) is one of the most popular summer plants. They flower for a long time until the frost sets in. If you let them overwinter in a frost-free place, these geraniums will flower again the following year. stunning red flowers, very conspicuous. Geraniums are easy to grow from seed. About 10 to 12 weeks after sowing, the first plants will flower.