Gardening Articles: Flowers :: Annuals
by Susan McClure
While gardening is generally an avocation requiring patience, this isn't the case with zinnias, one of the quickest flowers to bloom from seed. The huge range of flower colors, types, and sizes provides outstanding options for beds, borders, ground covers, containers, and cut flowers. Since I last wrote about them for this magazine 10 years ago, many new kinds of zinnias, including low-maintenance and disease-resistant types, have been introduced. These improvements may be just the impetus that brings these classic flowers, reminiscent of the roaring 1920s and country bouquets, into the gardens of a new generation.
Main Types of Zinnias
Zinnias come in two main types: the large-flowered, upright, often tall garden kinds; and the small-flowered, low, often spreading kinds. Plants that result when these kinds are bred are called interspecific crosses.
Plants range from compact miniatures through medium-height bedding and border types to tall cutting types. The flowers, which are actually clusters of individual florets, come in single daisylike flowers, formally tailored doubles, cactus-flowered types with quilled rays, and anemone-flowered forms with broad rays around a cushioned center. Zinnia flowers, from nickel to Frisbee size, bloom in lavender, orange, pink, purple, red, rose, salmon, white, yellow, and even green.
Garden zinnia (Z. elegans) is the parent of dozens of beautiful but disease-susceptible varieties. These are famous for producing lavish displays of flowers, which come in many sizes. Plants range from 6 to 50 inches tall and have bristly oval leaves.
Choices include fully double flowers less than an inch wide on nearly 2-foot-tall varieties such as 'Lilliput Mix', or on miniature varieties such as 6- to 10-inch-tall 'Thumbelina Mix'. The 24- to 30-inch-tall 'Sunbow Mix' has 1-1/2- to 2-inch flowers. In the 2- to 3-inch flower range, you can choose among the 10-inch-tall Lollipop series, the 24- to 36-inch-tall Ruffles series, or flashy 24- to 30-inch-tall 'Envy' with unique single or double green flowers.
The large-flowered zinnias are the ones that capture most gardeners' fancies. For 5-inch-wide blooms on long stems, look for 30-inch-tall 'Giant-Flowered Mix' and the disease-tolerant 40- to 50-inch-tall Blue Point series. These big bloomers benefit from deadheading, weekly if possible, and may need staking for extra support.
Spreading zinnias (Z. angustifolia) have small, 1- to 2-inch-wide flowers, usually orange or yellow with dark centers, and slim, lance-shaped leaves. They resist common foliar diseases and tolerate heat and drought. Growing in loose mounds and reaching 8 to 18 inches tall, they can serve as annual ground covers, and are also attractive in hanging baskets or at the front of a border. Varieties include golden-orange 'Classic', 'Crystal White' (a 1997 All-America Selections winner), 'Star Gold', and 'Star Orange'.
Interspecific crosses are low-maintenance zinnias that have been introduced over the last decade. They combine the flower colors of garden zinnias with the durability of spreading zinnias.
The front-runner in this group is 'Rose Pinwheel', a mildew-resistant 1988 release with 3-1/2-inch single dusty rose flowers on tidy 12-inch-tall plants. The Pinwheel series now includes flowers in gold, orange, pink on white, and white.
In 1999, 'Profusion Cherry' and 'Profusion Orange' won the first All-America Selections Gold Medals awarded in a decade. Both bloom early and repeatedly, flowering in my garden just 45 days after planting three-week-old seedlings. They produced an abundance of 2-inch-wide flowers up until the first fall frost, long after other zinnias were finished. They grow about 15 inches tall, covering the old flowers with new leaves and buds, and thus eliminating the need to deadhead.
Unless given light afternoon shade, flowers of 'Profusion Cherry', which also won a Fleuroselect Gold Medal in European trials, tend to fade from a deep vibrant cherry to bleached cherry as they age -- a look some people like.