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Zonal Geraniums Close to Perfection

Master gardener Maureen Gilmer, host of Weekend Gardening, explains why this near-perfect plant defies simple classification.

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	Red geraniums at this alpine chalet come indoors to winter over after a brief frost-free summer on the steps. (All photos courtesy of Maureen Gilmer)
	Lavender geranium: Dense form and vivid color characterizes the newer garden-variety geraniums.
	Early hybrid geranium: The early species of geraniums produced vigorous sprawling plants with single flowers in simple colors.
	English window: These English windowbox geraniums come indoors during the frigid winter.

Zonal Geraniums Are Nearly Perfect

By Maureen Gilmer

Aug. 6, 2007 — It's a tropical, annual, perennial and succulent. Maybe this is why zonal geraniums can be so confounding. This near-perfect plant defies simple classification because it tries to be all things to all people.

Technically an extensively hybridized member of genus Pelargonium, this fuzzy leaf plant is a tropical native of the frost-free southern tip of Africa. Or at least its species ancestors were, which have faded into obscurity. Horti-heads lump this multitude of progeny under Pelargonium hotorum hybrids or "zonals."

What northern gardeners love about zonals is their tolerance of growing both indoors and out. If left outdoors they become annuals, dying with the first hard frost of fall. Therefore they've been traditionally grown in pots so they may be brought indoors for the winter.

The long dry season in Africa lends a marked drought resistance to zonals, so while indoors, they live in a semidormant state with little to no winter-water needs. Plants remain green and beautiful in a bright sunny window and may even bloom modestly if conditions are right. But come spring they are back outdoors again to thrive and flower abundantly over the long summer months.

In mild climates such as Los Angeles, zonals became a signature of the 20th-century migration to southern California. Easterners who knew them only as potted plants suddenly found that zonals make exceptional garden plants in their new homes. The zonal's natural African love of sun and dry conditions made them perfectly adapted to early bungalow gardens and housing courts. There they attained mammoth sizes, unhindered by pruning or pots. All over the city the full range of its floral potential can still be seen today.

What drove these plants was their ease of propagation due to their natural succulent nature. Just about anyone could take a cutting and root it. Geraniums are semi-woody but succulent, so you can break or cut a piece off and press it into sand or water to strike roots. When northern gardeners brought their plants indoors at season's end, the pruning to a smaller size yielded a rich harvest of cuttings. These were naturally rooted to create even more copies of the original.

This led to a lot of trading in newly built communities after the wars. Many garden varieties spread far and wide as pass-along plants. Few of these early ones had names attached at the time, and no doubt spontaneous hybrids occurred, which compounded the diversity. Zonals were frequently sold and traded on their flower color alone, or sometimes by leaf size, pattern or shape.

This succulent nature also makes zonals difficult to grow in hot, humid climates. Excessive moisture is the Achilles heel of all succulents, and where there is significant rain in summer, the plants don't have time to dry out. In this climate, growing in pots where they receive plenty of sun but protection from rain will keep them happy and blooming.

Today there are a huge variety of zonals available. Many are bred to remain short stature for mass bedding displays. These sport immense clusters of flowers in every shade of red, pink, orange and white. More upright forms make better landscape plants over the long term, becoming rather shrubby with time. Whenever zonals become leggy and reluctant to produce foliage as they should, cut them back significantly to encourage new growth tips at the base of the plant.

Growing zonals is cheap and fun, but be aware there can be pilferage. It's not uncommon to see a little old lady surreptitiously nip and pocket a cutting from some public plant. And young cash-strapped gardeners don't escape guilt either. But alas, that is the affliction of all succulents, for they all refuse to wilt or die in the pocket, living to root once again far from home.

(Maureen Gilmer is a horticulturist and host of Weekend Gardening. E-mail her at mo@moplants.com. For more information, visit: www.moplants.com. Distributed by Scripps Howard News Service.)

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