In honor of 2012 being the Year of the Geranium, the
National Garden Bureau brings you some quick facts about this much-loved garden
1. The bedding plants gardeners plant in late spring and
bring inside in autumn are commonly known as geraniums; but geraniums they are
not. They are pelargoniums.
2. True geraniums are the cranesbills, hardy North American
and European herbaceous perennials; while pelargoniums are semi-tender or
tender plants, mostly from South
Africa, that have graced our gardens with
their large flowers for decades. (It’s a rather lengthy story about why the
difference and to read that, go to the NGB website.) For this
article, we will still refer to the annual bedding plants as geraniums.
3. Traditionally, plants were grown from cuttings
(vegetatively propagated). However, in 1962, Dr. Richard Craig of Pennsylvania State University
developed a technique for seed scarification (nicking) and bred the first
commercially successful open-pollinated, seed propagated geranium, ‘Nittany
Lion Red’. Four years later, the first F1 hybrid geranium from seed was
Four basic types
1. Common or Zonal Geraniums (Pelargonium x hortorum) – This is the classic bedding plant, which
typically comes to mind when someone says “geranium.” Deriving its name from
the “zoned” leaf markings, it thrives both in containers as floriferous single
specimens as well as planted out in swaths awash with color in the landscape.
2. Regal and Angel Geraniums (Pelargonium domesticum) – The Regals, which also are known as
Martha Washington geraniums, are bushy plants with large blossoms, single or
double flowers in dramatic colors and patterns. Regals tend to be spring
blooming, requiring cool nighttime temperatures to bud. Angels are smaller
versions of Regals developed for their dazzling blooms, which look somewhat
3. Scented-Leaf Geranium (Pelargonium domesticum) – Scented-leaf geraniums are coveted
heirloom plants, still grown today for their pleasing fragrance, unusual
foliage, delicate flowers, essential oil and culinary use. The scent, created
by oils in the leaves, is released when the leaves are rubbed or bruised. The
fragrance of a scented-leaf geranium may remind you of roses, lemons,
pineapple, chocolate and other spicy fragrances.
4. Ivy-Leaf Geranium (Pelargonium
peltatum) – Plants with long, brittle stems full of sculptured, ivy shaped
leaves and gracefully trailing habits are immensely popular for hanging
baskets, window-boxes and containers. Flowering abundantly throughout the
summer, they have smaller, looser flower umbels of single, semi-double or
double blossoms in shades of deep maroon, red or pink.
When shopping for geranium plants, choose plants based on
their color and size. Look for healthy leaves, with no discolored spots above
or underneath, fairly compact growth with no straggly stems that indicate it
was grown in poor light, and no obvious pests
Geraniums as bedding plants
Geraniums are popular garden plants because of their
long-lasting flower displays, even under adverse weather conditions. For
maximum bloom, plant where they’ll get at least 4 to 6 hours of direct sunlight
daily and space them 8 to 12 inches apart. Geraniums need good air circulation,
but should be protected from strong winds, which can break their brittle
Geraniums should be planted in moisture retentive, but well-drained
garden soils, at the same level as they were growing in pots. Mulch when
possible to reduce soil temperature extremes and weed growth. Promptly deadhead
spent flowering stems to promote additional flowering. Pinch stems to prevent
legginess and promote bushiness.
Water geraniums regularly if there is no rain, preferably
early in the day to allow leaves and flowers to dry before nightfall, which
will help prevent disease problems.
Geraniums in containers
Popular mainstays for containers, hanging baskets and window
boxes, geraniums are well-behaved, low-maintenance, high-performing garden
Use a container with drainage holes to prevent soggy soil,
which can cause root rot. Fill the container with a good quality soil-less
potting mix (not dirt) and position in full sun.
Water thoroughly, allow to dry out before watering again. Do
not use a saucer under the container unless filled with pebbles. Fertilize
every 2 weeks with a balanced water-soluble fertilizer at half strength.
Few plants offer such variation in flower color, growth
habit, leaf pattern, and scent. Lush growing geraniums are versatile plants
perfect for any spot that calls for a splash of sparkling color throughout the
The National Garden Bureau recognizes Betty Earl as the
author of the full version of this article, which can be found on the NGBwebsite.
Founded in 1920, the National Garden Bureau is a non-profit
organization whose mission is to disseminate basic instructions for home
gardeners. NGB publishes and sponsors “Year Of The” fact sheets annually
featuring flowers and vegetables, including new introductions, which are
especially suited to home gardens.