Geraniums belong to several botanical genera, but the most common species found in gardens is the zonal geranium (Pelargonium hortorum), states the University of Minnesota Extension. This perennial is hardy to zones 10 and 11. If you live north of zone 10, you can grow these plants as annuals or in pots brought inside during the cooler months. Zonal geraniums, with their rich clusters of white, pink, red, lavender, fuchsia or multicolored flowers, are a treat to have in any garden. Select other flowers to go with your geraniums to compliment their beauty or to create a theme.
Geraniums prefer to grow in an area that receives full sun and in well-drained, organically rich soil. The soil pH should be 7.0 (neutral) or slightly above. The flowers that you select to plant with geraniums should have the same growing requirements. The great news is the majority of flowers prefer a lot of sun and the same soil conditions. Examples of such annuals are zinnias, petunias, snapdragons and chrysanthemums. Perennials that have the same growing requirements as garden geraniums are hollyhock, columbine, canna lily and gladiolus.
There is no right or wrong when deciding on a color scheme; it all comes down to personal taste. Some successful combinations include a complimentary color scheme, which means combining two colors that are opposite one another on the color wheel, and an analogous color scheme, which involves using adjacent colors on the color wheel or different shades of the same color. If you were going for an analogous color scheme, you could plant orange purslane and yellow, orange or red French marigolds with red geraniums; this would also provide a height contrast since both annuals do not grow as high as geraniums. For a complimentary color scheme, baby blue eyes would work nicely with orange geraniums; yellow black-eyed Susans would compliment purple geraniums. Note that black-eyed Susans are perennials hardy from zones 3 to 9.
Geraniums, because of their fragrance and rich nectar source, attract butterflies, states Colorado State University. According to the University of Florida IFAS Extension, red geraniums are most attractive to these beautiful insects; they also appeal to hummingbirds. You can create a whole butterfly garden by including flowers such as zinnias, cosmos, marigolds, phlox, asters, verbenas, sunflowers, snapdragons and rose mallow with your geraniums.
Geraniums can also help deter insect pests due to their strong fragrance. This makes them ideal for keeping produce in your fruit and vegetable garden safe. According to Golden Harvest Organics, geraniums are beneficial companion plants for roses, tomatoes, peppers, corn, grapes, cabbage and any other plants that Japanese beetles, leaf hoppers and cabbage worms attack.