Pelargonium hortorum, also known as zonal geraniums, are a classical garden flower. These plants yield luscious, large clusters of flowers in numerous colours. The blossoms are set atop long stalks, high above the plant's foliage. Zonal geraniums have several subcategories including rosebud, carnation, phlox-eyed, stellar, fancy-leaf, speckled and variegated leaf geraniums. Several further subcategories of variegated leaf cultivars exist.
Fancy Leaf Geraniums
As the name implies, fancy leaf geraniums have very showy leaves with colours ranging from white and cream to yellow. This is a simple variegation. Alternatively, some fancy leaf geraniums, like butterfly leaf geraniums, have a darker streak of colour appearing on the white and green variegation, making that area look red.
Fancy leaf geraniums like Madame Salleron, Whilhem Langguth, and Platinum cultivars grow best in partial shade. Plant them where they receive morning sun followed by shade through the afternoon for greatest success.
Ivy geraniums (Pelargonium peltatum) are perfect as ground cover plants or as additions to hanging planters because of their trailing nature. The plants include variegated types, some of which yield striped flowers too. Cultivars of variegated ivy include mint-scented rose, Lady Plymouth, Frosted and Atomic Snowflake.
Hardy in USDA zones 9 to 11, the ivy geranium appreciates full sun. if temperatures go over 29.4 degrees Celsius, they require some shade during the hottest parts of the day.
Angel and Royal Geraniums
Angel geraniums (a Pelagonium crispum derivative) and royal geraniums (Pelargonium X domesticum) both have relatively small flowers with upper petals being slightly lighter than the lower ones. Common colours include red, lavender and pink. Both occasionally have variegated leaves of the white-yellow type. Among angel geraniums, look for Rita or the Ainsbury Beauty for variegation; among the Royals, watch for Golden Coral, Peach Princess, Love Song and Gilda.
Both types of geraniums need very consistent levels of water, otherwise oedema develops. Plant in fertile, neutral soil.
- North Carolina University Extension: Geranium Culture for Home Gardeners
- Washington State University Extension: Geraniums
- University of Massachusetts Extension:
- Iowa State University Extension: Ivy Geranium
- Geraniums Online: More on The Geranium Family (Geraniaceae) & the Genus Pelargonium
- NDSU Extension Service: Begonia