Zinnias are the Toyota Camrys of the flower border. Every year, new annuals like 'Serena' angelonia and'Snow Princess' sweet alyssum come along, delivering more color for more weeks with less work than the flowers before them. Yet at the end of the day, one dependable old favorite on the garden center lot still begs to go home with us. The zinnia.
Say "zinnia" and I bet the image that pops into most gardeners' heads is a lot like the one above -- the big-flowered common zinnia (Zinnia elegans). It grows up to 4 feet tall and boasts flowers up to 5 inches across in just about every color except blue. The blooms make great cut flowers -- the more you cut, the more you'll get -- and butterflies love them. 'Park's Picks,' a double-flowered strain I photographed at Becky Savitz's garden in North Carolina last week, sport fully double blooms with a greenish-yellow eye.
Lots of Spots Unfortunately, as Becky will attest, when common zinnias are grown this closely together and you get rainy weather, they fall victim to a varieties of leaf diseases, including powdery mildew and and several leaf spots. Spraying according to label directions with a systemic fungicide such as Immunox before diseases show up can prevent them, but once these rogues appear, you're pretty much left with just picking off and trashing infected leaves. Because high humidity favors these diseases, plant common zinnias in sunny, well-drained spots. Avoid wetting the foliage when you water and don't crowd plants.
Trouble-Free Zinnias Insect and disease problems associated with common zinnias caused a lot of us to look for a trouble-free type. In narrowleaf zinnia (Zinnia angustifolia), we found it. It gets its name from its slender leaves. Unlike common zinnia, it's a mounding plant and grows about 16 inches tall and wide. The blooms are smaller, about an inch wide, but it flowers profusely. While it's not great for cutting, narrowleaf zinnia doesn't need deadheading to keep blooming either. It resists mildew and leaf spot and is much more drought tolerant than common zinnia.
Flower colors of early strains, such as Classic, Crystal and Star, were limited to orange, yellow, and white. Then plant breeders asked themselves this question: "Is it time for a beer?" All agreed it was and after downing a few, they asked a second question, "Could we cross common zinnia and narrowleaf zinnia and come up with something that combines the best traits of both?"
They did. Good beer will do that. And that's why we now can plant zinnias that are more compact, disease-resistant, and drought-tolerant than common zinnias and also have bigger flowers in many more colors than narrowleaf zinnias. In general, the new zinnias such as the Zahara and Profusion series, form a lower, tidier mound than Classic and Star -- about a foot tall and wide. The blooms can be single or double. Here are a few goodies.
It's Not Too Late to Plant!
Think you've missed your chance at zinnias this year? Nope. Zinnias are just about the fastest and easiest annuals to grow from seed, so if you start now, you can weeks of great color in August and September, right up until frost. Though zinnias take hot weather, they also love the fall. Look for seeds at garden centers now. If they don't have them, Park Seeds is a good mail-order source for all kinds of zinnias. Or go with transplants for even earlier blooms.
Zinnias like fertile, well-drained soil and as much sun as they can get. Go easy on the water, don't wet the foliage when you water, and soon you'll be singing the praises of these old favorites.
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