Continuing on with the genus Pelargonium, let’s focus in on the Zonals. These are the classic geraniums with the big, heads of bright flowers offered at every nursery in spring and summer. They are almost fool proof for summer color and have earned their position of popularity in Oklahoma gardens.
Specifically Pelargonium zonale, Zonal geraniums acquired the name because of the “zones” of color on the foliage. Pale or prominent, concentric dark bands bring interest to the plant even before the blooms begin. Their foliage is rounded with a slight scallop. Zonals are not to be confused with “Stellar” pelargoniums that bear multi-pointed leaves with color zones and star-shaped florets. “Fancy-leaf” zonals may have bi- or tri-colored foliage, but will always have numerous blossoms creating a full, round flower stem.
Zonals are an annual that do great in containers and window boxes. The semi-succulent stem helps the plant live through short dry spells. In fact, too much water in poorly drained soil can bring yellowing and leaf drop.
Although sold as an annual, plants may also be dug in the fall, pruned back and potted until the following spring. Potted plants need simply to be moved to a cool, dry location. Light in winter is relatively unimportant — the plant is in a dormant state even though it may retain some foliage.
Remember to wait for warmth before bringing them out of hibernation. At this time, transplant any root bound plants into a larger container, water thoroughly and walk away.
When the plant begins to send out new growth, prune the stems back to maintain a full, dense plant. (A plant in active growth will send out new shoots quicker than one trying to emerge from dormancy.) When completely dry, re-saturate the soil until the transplant is fully rooted in its new container.
Cultivation is pretty straight forward. Easy to grow from seed or small plant, set transplants out when temperatures warm in the spring.
Pinching the tips on a young start will create a full bodied plant. (Unpinched, some species can grow up to three feet tall.) Feed weekly during the growing season with a liquid manure or all-purpose fertilizer. If you intend to overwinter your Zonals, decrease fertilizer as fall approaches to let the plant harden up.
Gardeners find pleasure in a variety of flowers. Zonal geraniums, popularized and bred since the mid-nineteenth century, definitely are a proven winner.
LeeAnn Barton has worked with nurseries for more than 20 years. She digs in the dirt in Stillwater. Direct questions to her by emailing email@example.com.