They may be at the end of alphabetical listings of annuals, but zinnias are at the top of the list when it comes to garden appeal.
In late summer, when other flowers are fading, zinnias are just reaching their peak, blooming into October. They grow 6 inches to 4 feet tall and come in every color but blue. Their blooms range from buttonlike heads and daisylike flowers to double blossoms that resemble dahlias. They are American natives, originating as a purplish wildflower from the Southwest United States, Mexico and Central America.
Z. elegans, known as the common zinnia, offers single and double flower heads 1 to 7 inches across in multi- and solid colors. Z. angustifolia produces single, daisy-like golden-orange blooms on plants with very narrow leaves. Z. haageana, also known as the Mexican zinnia, bears 1- to 2-inch single and double flower heads in tones of red, mahogany, yellow and orange in solid colors and two-tone variations.
"There are a lot of new, improved varieties out, but people still go with the old standbys, the ones they grew up with. One that seemed to be popular this year was the 'State Fair' mix, which is a taller variety," said Kathy Matousch, a greenhouse supervisor for the Siebenthaler Co.
Two new zinnias that have received a lot of attention in the past year are the 1999 All American Selections gold-medal winners 'Profusion Orange' and 'Profusion Cherry.'
The National Garden Bureau has declared 2000 as "The Year of the Zinnia."
"Zinnias are very easy to grow from either seed or from started plants," said Nona Koivula, executive director of both All American Selections and the National Garden Bureau, two nonprofit organizations that share facilities and staff in Downers Grove, Ill.
The bureau's mission is to "disseminate accurate information on gardening," and All American Selections is an organization that tests and introduces new varieties of flowers and vegetables to the public, Koivula said.
The two 'Profusion' zinnias won gold medals for their prolific blooming and for their tolerance to diseases that plague zinnias, including powdery mildew and bacterial leaf spot. Also, unlike most zinnias, they don't need to be deadheaded to promote continuous bloom. The 'Profusion' zinnias, which produce single-form blooms are a cross between Z. angustifolia and Z. elegans.
"They are really a neat flower. They start blooming earlier than the others and they just bloom like crazy," Matousch said. They are also on the shorter side, 12 to 18 inches tall, which makes them a nice plant at the front of the flower border.
All zinnias are susceptible to rust, powdery mildew and leaf spot if they are grown where there is too much moisture, too much shade and overcrowding, Matousch said.
"A lot of times when they are planted too close together, they don't get a lot of good air movement, and that causes the disease problems," she said. A general fungicide, used early in the season, often wards off disease problems, she said.
Varieties to consider:
'Profusion Orange': Single, orange, 2- to 3-inch blooms on 12- to 18-inch plants.
'Profusion Cherry': Single, rose, 2- to 3-inch blooms on 12- to 18-inch plants.
'Crystal White': 1997 AAS winner. Single, white blooms with golden yellow centers that are 1 to 1 1/4 inches wide on 8- to 10-inch plants.
'Border Beauty' series: Semi-double to fully double blooms, about 3 1/2 inches across on 20-inch plants.
'Peter Pan' series: Slightly curled, double flowers up to 5 inches wide on 12-inch plants.
'Ruffles' series: Ball-shaped, 2 1/2 -inch heads with ruffled petals on 24- to 30-inch-tall plants. These make good cut flowers.
'Thumbelina' mix: 1 1/2 - to 2-inch blooms on 10- to 12-inch plants. Good choice for window boxes and other containers.
'Zenith' hybrids: Available in many colors, with cactus-type flowers on 30-inch-tall plants.
'State Fair' mix: Purple, red, yellow and orange 5- to 6-inch blooms on 30-inch plants.
Zinnia facts and figures
Common name: Zinnia.
Genus: Zinnia (ZIN-nee-ah).
Family: Compositae (daisy family).
Plant type: Annual.
Size: 6 inches to 4 feet high and 6 inches to 14 inches wide.
Bloom season: Summer until frost.
Color: All colors except blue.
Light: Sun half day or more.
Soil: Well-drained, from moist to the dry side.
Fertilizer: 5-10-5.
Pests: Japanese beetle, spider mites, aphids (usually not a problem).
Diseases: Leaf spot, powdery mildew, rust.
Note: Deadheading increases bloom. Encourage bushiness by pinching plants when they are young. Cutting blooms for bouquets also encourages new growth. Water in the morning and avoid wetting foliage to prevent disease. They last a long time as a cut flower.