Gardening : Big, Colorful Zinnias Greet the Summer Sun : Easy bloomers: Simple to grow from seeds, these annuals burst forth in all their glory in the heat of July.


Not many flowers are grown from seed these days, but zinnias are worth the effort. These easy summer annuals reward the grower with bright flowers up to six inches across that look right at home in city or country gardens as well as in charming bouquets.

Last year I got a late start on my summer flower garden, not planting my zinnia seeds until July. The recommended time is May or June so that plants can become established before the intense summer heat.

Because I hadn’t placed a catalogue order, I went to my neighborhood nursery and bought several packages of zinnia seeds. But I also purchased some zinnia seedlings, thinking they would give me an earlier crop.

I was surprised to learn that the nursery seedlings, even with their head start, bloomed only 10 days ahead of my seed-grown plants. The flowers of each group were lovely, but the seed-grown plants cost a fraction of what I spent on the nursery plants, and the seeds provided hundreds of plants--many more than I could use.


Zinnias come in a wide variety of forms and sizes. My favorites are the large cactus-flowered blooms that look like mop-headed daisies. I’m also fond of the smaller lilliput (pompon) variety whose thickly layered petals resemble parakeet feathers.

The more formal dahlia-flowered zinnias display large blooms with flat petals, while the Haageana or Mexicana type has 1 1/2-inch flowers with pointed petals bordered with a contrasting shade.

Zinnias are embarrassingly easy to grow. Children often do as well as expert gardeners. The seeds are large, unlike those of petunias or snapdragons, so there’s no difficulty seeding them or spacing them appropriately.

In prepared soil, dig a furrow about an inch deep. Drop the seeds about four inches apart. Cover with one-eighth inch of soil and water gently so that the seeds are not washed away. Keep the soil damp until the seeds germinate--usually in four to eight days. Thin the seedlings to 10 inches apart, transplanting extras to bare spots or into pots.


The biggest problem with zinnias is mildew, especially along the coast where I live. Its effects can be reduced by planting zinnias early enough in the summer that they can bloom before late September--when the days shorten and plants are moist at night. It’s also wise to keep the foliage dry by watering only the roots. At the first sign of a white powder dusting the leaves, spray with a fungicide, such as Funginex.

One summer I tried the species Z. augustifolia (also called zinnia classic, Z. linearias, or thin-leaved zinnia). Its 1 1/2-inch golden-orange semidouble blooms are not nearly so striking as those of today’s hybrids, but the plants had one especially appealing characteristic: no mildew, even in my humid climate.

Now I see that the Burpee hybridizers have crossed Z. elegans with Z. augustifolia to produce a pink 2 1/2-inch bloom said to be mildew-resistant. I’m eager to try this new variety, Rose Pinwheel, in this summer’s flower garden.

Along with it I will plant pink statice, rose shades of strawflower, blue salvia ( S. farinacea Victoria), pink cosmos, rose cleome and gloriosa daisies. The gold centers of Rose Pinwheel should blend nicely with the gold daisies, and blue is always an excellent complementary color.


Because they take longer to flower, I’ll start the strawflowers in flats a couple of weeks before they go into the garden. All the other plants will be sown directly in the garden. Although blue salvia is easy to grow from seed, it’s a perennial (often grown as an annual) that takes several months to begin flowering, so it’s one summer flower that I usually purchase from the nursery.

To use water as efficiently as possible, all my plants will be grown alongside soaker hoses. Although some irrigation systems are quite sophisticated (what with computer timers and multivalve stations) mine is simple.

For each tier of my garden where annuals are sown, I use 150 feet of soaker hose that connects to the garden hose. I allow the water to run about five hours, gently, twice a week. By monitoring the soil dampness, I can determine whether to apply more or less.

For gardeners who prefer the speed and convenience of seedlings, several familiar zinnia strains can be found at garden centers.


The largest is dahlia-flowered State Fair, a reliable favorite that’s been around for years. Peter Pan, Pulchino, and Cut-and-Come-again zinnias produce three-inch flattened blooms on 12- to 18-inch bushes. The smallest zinnia, Thumbelina, is cute but it’s in bloom for such a short time that it seems hardly worth the effort.

Terry Hartog, who raises thousands of bedding plants for his Vintage Nursery in Lakewood, likes to use zinnias as backdrop plants. He favors a mass planting of Peter Pan (because of its relatively large flower size and compact growth) bordered by white vinca Little Bright Eye. The vinca hides the lower leaves of zinnias, which can become unsightly.

Terry says: “Both vinca and zinnias are good bets for hot-weather areas because they can stand up to the heat.”

The best selection of zinnias is in such catalogues as Burpee Gardens (featuring zinnias on the cover), Warminster, PA 18974, and Park Seed, Greenwood, SC 29647-0001, Most local garden centers also have a variety of zinnia seeds.