As August approaches, the flower gardens are lush with maturing annuals and we are beginning to enjoy the produce of the summer vegetable gardens.

Perennial flowers are the timekeepers of the ornamental garden, coming in on cue each year to give our seasons their familiar flavors. The dashing day lilies and handsome hostas of summer are with us now. The common perennials of spring and summer abound because everyone's a gardener in the spring. The urge to plant and what's available then has given us flowers through the summer at most.

Could there be more? Is the conventional wisdom of fall as a season of cleanup chores and bulb planting complete?

The answers are yes and no respectively: Yes, there is much more the garden can be if we expand our plant palettes and visions to include fall interest, a current catch-phrase of garden designers.

Here in central Pennsylvania, we have ideal conditions for the development of this "neglected season," as Allen Lacy calls it in his inspirational book, "The Garden in Autumn." The time Lacey refers to is late August through October and even up to Thanksgiving for the most adventurous among us. The days are still warm and the nights become cooler and longer, a pleasant time to be outside in the garden. Our town becomes active with school and football games, many people returning and visiting - another reason to have the garden looking its best.

So why have we not heeded this season much interest? Lacy suggests three possible answers. First, and most obvious, is the natural fireworks of our surrounding woodlands at this time. Color surrounds us on a big scale in the trees and shrubs. We enjoy the fall spectacle in the surrounding landscape but could bring this grandeur closer to our own home plots with a little planning and imagination.

Second; Lacy suggests, we are stigmatized to believe that fall or autumn is metaphorically the time of decline. We forget that leaf-fall is an ending in part, but also reveals the beginnings of bud formations on azaleas, dogwoods and rhododendrons that will flower next spring.

Many annuals and perennials will survive the first "killing frost, " when the temperature drops below 32 degrees, which occurs in mid to late October for U.S. Department of Agriculture zones 5 and 6 of central Pennsylvania, depending on your location and micro-climates.

Established annuals such as marigolds and petunias can easily be covered with an old sheet on nights when frost threatens, to extend their color for weeks.

The final reason, Lacy writes, why we have neglected the possibilities of the autumn garden is, to me, the most interesting. Our horticultural traditions and literature have been based to a large degree on those of Great Britain.
England, he suggests, is "a nation of spring and summer gardeners. English gardens have very little to teach us about fall." The mild summers of England permit the growing of plants we often struggle with, such as delphiniums and roses, in our oppressively hot and humid Julys and Augusts.

Likewise the long-seasoned plants that reward us with fruits, berries, flowers and seedheads in the United States, notably the fall-blooming sedums, eupatoriums, cimicifugas and the wonderful array of ornamental grasses, are not reliable options in the drizzly, chilly gray days of autumn in Great Britain.

As to how to extend your perennial garden's interest to include fall, there are a number of approaches.

First, include perennial plants which linger, whether with flowers or foliage, from summer into fall. Artemesias, with their fine gray foliage, and rudbeckias, for their prolific bright flowers, are two examples. Salvias, stachys, dianthus, gallardias and gauras are the genus names of others that, when deadheaded and even cut back mid-season, will perform much longer than if left unattended in the garden.

Next, there are perennials specific to the fall season that you can seek out at garden centers and nurseries. Japanese anemones, New York and New England asters, boltonias and, of course, chrysanthemums are the flowers that announce fall is here. Many of them are available in exciting new cultivars of ever-expanding color and design possibilities. Their blooms are actually triggered by the decreasing number of daylight hours that comes with the changing season.

Many of the perennials which bloom in fall are native to this continent, which makes some gardeners overlook them. The current trend is to use as many reliable natives as possible for garden building blocks because they fit the culture of the landscape and a healthy plant is usually a beautiful one. These fall bloomers, such Joe Pye weed, the asters and grasses, are often big plants too.

Remember they've had a long season to develop and need to have proper placement to permit this. Many, such as the large miscanthuses (grasses) and asters, make fine backdrops for earlier perennials. An entire bed of fall interest plants can be sited at the fur corner of the landscape because it can be seen easily from a distance.

Though fall planting is fine and even preferable for deciduous trees and shrubs, many perennials that bloom in fall, including most grasses, need to be planted in spring so they have enough time to establish sufficient roots to carry them over the winter.

Perhaps that's another reason so many gardens in our region lack fall interest. When we finally see these giants in their full glory, it's late in the season and we've missed the best time to plant them. Other than the discount-store chrysanthemums and ornamental cabbages (which both must be considered as annuals if planted in fall), there is little color to bring the large-scale foliage fireworks down to ground level.
We must be determined to remember their genus-and species names in order to find and plant them next spring.

Mumina Kowalski, a Penn State Master Gardener from Boalsburg, works at the Centre Furnace Mansion.
For answers to your gardening questions, contact Master Gardener by e-mail at centreext@psu.edu