Geraniums, A Flower with Flair

By Dr. Leonard Perry, Extension Professor University of Vermont

Some flowers have it all--flair, versatility, and attractiveness. Geraniums fall into this category, performing as well in formal bedding gardens as they do in a simple clay pot.

There are approximately 250 species of geraniums with more than 10,000 different cultivars. The most popular color is red although white, pink, coral, salmon, magenta, and violet are increasing in popularity.

Discovered in South Africa by traders rounding the Cape of Good Hope, geraniums quickly gained acceptance in England in the late 17th century. In 1786 Thomas Jefferson was so enamored with the geranium that he sent plants from France to horticulturist John Bartram in Philadelphia who introduced them to America.

Fascination with the geranium continued over the next century with several successful attempts to hybridize. Between 1810 and 1920 Robert Sweet's five-volume book on geraniums was published and became the definitive guide to this interesting plant variety.

Today plant breeders are developing varieties for new colors, compactness, heat tolerance, disease resistance, and earlier, longer blooming time.

There are four basic types of geraniums:

COMMON OR ZONAL GERANIUMS--This is the most popular garden geranium, deriving its name from its "zoned" leaf markings. It has clusters (umbels) of many individual flowers held on long stems above the foliage. The two types of zonal geraniums include "cutting" and "seed."

Cutting varieties, which are vegetatively propagated from stock plants, have flower heads with large, double florets. They provide great early season display. Seed geraniums are propagated from seed and were developed as a smaller, more uniform plant for use as a bedding plant. They are heat resistant and impressive when massed in the garden and provide beautiful late season display.

IVY GERANIUM--Named for the ivy-shaped foliage and trailing growth habit, the flowers are more subtle and pastel than zonals. These varieties prefer cool, sunny conditions and are ideal for hanging baskets, window boxes, or ground covers.

SCENTED-LEAF GERANIUM--These geraniums are available in many flavors including lemon, peppermint, nutmeg, coconut, mint, and apple and can be used in cooking or fragrant, dried pot pourri. To release the scent, rub the foliage.

SHOW, REGAL, OR MARTHA WASHINGTON GERANIUM--These large, colorful single or double-petaled flowers are often bicolored with decorative stripes. They thrive best in cool, sunny locations and will bloom throughout the season where temperatures do not exceed 60 degrees F. Plants may stop flowering in the heat of the summer but will resume once the weather cools in the fall.

Most geranium varieties prefer bright, sunny locations (ivy types like cooler, dappled light). Soil should be moist, well drained, slightly acidic, and high in organic matter such as peat moss. Geraniums thrive in average to cool temperatures and should be planted outdoors well after the danger of frost is past.

Work in a complete fertilizer like 5-10-5 before planting. In mid-summer fertilize again with water-soluble fertilizer unless you incorporated organic matter into the soil before planting. Space plants 10 to 12 inches apart. Water well after planting, but don't overwater.

Geraniums are also ideal for containers. Use sterilized potting soil, and top-dress with a slow-release fertilizer according to package directions. Water thoroughly when the soil is dry to the touch (so water comes through the drainage holes).

Geraniums are a great addition to any garden. So, why not buy a few this year for your window boxes, hanging baskets, and flowerbeds.

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