by Diane Sagers

CORRESPONDENT

Zinnias are a lovely addition to many of the gardens around Tooele County and their popularity is well-earned. These flowers come in a wide range of sizes and bright, clear hues to set off nearly any garden plan. These garden annuals add their color from summer through frost. One of the reasons for the zinnia's popularity is the diversity of its forms. Like dahlias and chrysanthemums, zinnias have a variety of flower forms and may be single, semi-double, or double.

These flowers have long been brightening the landscape of the Americas, as they originated here. However, their current popularity is not as long-lived as their history. When the Spanish arrived and saw the wild zinnias of Mexico, they apparently disliked them. They named them mal de ojos, or sickness of the eye, because they thought the flower was so unattractive. Who knows? Perhaps these ancient ancestors of today's blossoms were covered with powdery mildew -- a malady common to these plants.

In the 1700s seeds of these plants were sent back to Europe where they remained unknown and unloved. Dr. Johann Gottfried Zinn took an interest in the flowers and wrote the first description of them. The flower was named for him. It is hard to say if he found that a compliment or not.

Plant breeding began in Europe during the 1800s and two lovely strains, Mammoth and Striata, caught on in America. Breeding has continued and the results have produced superior plants both for looks and for disease-resistance.

Because zinnias have so many petals, it is difficult to get to the male and female reproductive parts to cross-pollinate them without destroying the flower, but in the 1950s, John Mondry, a breeder for the W. Atlee Burpee Company, found a plant in their fields that had no petals, but were composed of entirely female reproductive parts. They could form seeds only when cross-pollinated.

By using that plant, the company was able to develop a series of plants known as F1 Hybrid 'Peter Pan.' These were introduced from 1971 to 1980 with more additions since then.

More than a dozen zinnia species exist, but only three are generally grown in home gardens. Among those three are a wide range of varieties and colors.

Most familiar is zinnia elegans, which grows in tall, medium and dwarf sizes in multiple layers of petals. You can find them in every color except blue. You may not know Z. angustifolia (also known as Z. linearis) but I suggest you get acquainted. These plants grow with narrow foliage and single flowers that are more powdery mildew resistant in our area than zinnia elegans.

Angustifolia has golden-orange flowers, but the variety, 'Crystal White' (All-America Selections winner for 1997) offers pure white blooms with yellow centers. 'Crystal White' is also more compact than the species variety, which can spread to 2 feet. Probably the least known of zinnias is Z. haageana, or the Mexican zinnia. It is disease-resistant, grows to 15 inches, and has small, bicolored flowers. It's an excellent cut flower because of its long stems.

As property sizes around homes have shrunk, garden plots have also diminished proportionately. Container gardens on decks and patios are more widespread and compact zinnias have taken their place. The profusion series of zinnias, 'cherry' and 'orange,' as well as 'Crystal White' are well adapted. All three are All America Selection varieties.

It is too late to plant them this year, but these lovely flowers deserve some consideration as part of your garden next summer. They grow well in full sun with six or more hours of direct sun daily. They prefer a soil that drains well, but they will grow in just about any soil, whether it's a clay, sandy or loamy type. Cut the blossoms frequently to keep the plants compact and bushy and to encourage more flower production.

Zinnias aren't heavy feeders, but fertilize plantings in the garden at least twice during the growing season with a balanced granular or water-soluble fertilizer. For instance, one with 20-20-20 on the label.

Zinnias are basically pest free in our area except for powdery mildew. Until recently, you could pretty well plan for your zinnias to look like a mess by late summer and early fall with the light gray mold. The best offense against the fungus was and is prevention. Don't let the leaves stay wet and do space the plants so they have good air circulation. Choose Z. angustifolia and Z. haageana, which are powdery mildew resistant varieties if you find that powdery mildew is a problem for you. Newer plants, especially the interspecific crosses of Z. elegans and Z. angustifolia, such as the 'Profusion' series, are very resistant to powdery mildew.