(It's available at local garden centers and bookstores, or can be ordered directly from the Brooklyn Botanic Garden, 1000 Washington Ave., Brooklyn, N.Y. 11225, for $6.95, plus $3.25 for postage and handling. Ask for Handbook No. 128.)
Local contributors to the guide include Darrel Apps, who runs Garden Adventures, a garden consulting business near Kennett Square. Recognized nationally as a daylily breeder, Apps has been extolling the virtues of daylilies and other perennials for a couple of decades. Many of his observations are collected in helpful charts outlining the blooming periods for perennials that will perform well in the Philadelphia area.
Newcomers to the world of perennials need to be aware that they may not be able to coax the same length of bloom as Apps does from asters, daylilies, salvias, coreopsis and veronica. But at least his charts provide a good list
from which to start.
In another of the essays in "Perennials," Yvonne England, proprietor of England's Herb Farm in Honey Brook, discusses the addition of herbs to the perennial border, and encourages gardeners to include these plants for their textures and foliage colors. Some of her favorites for foliage color are rue, with special attention given to Ruta graveolens Blue Beauty; the taller cultivar Jackman's Blue, and the tall, tropical-looking Angelica gigas, which has "vivid purple six-foot stems which unfurl large, purple, spherical flower heads in summer." Many herbs are easy to cultivate, resisting pests and diseases and surviving dry periods with ease.
Jack Potter, horticulturist at the Scott Arboretum in Swarthmore, thinks that "perennials by themselves often lack structure," so he prefers to grow them in combination with shrubs - and especially with roses. In search of a ''rough and tumbling mingling of roses and perennials," Potter shuns the modern hyrbid teas, grandifloras and floribundas. Instead, he recommends old garden roses, as well as some of "the modern shrub roses, rugosas, hybrid musks, the Meidilands and David Austin's splendid new English roses."
An essay by Ken Druse, contributing editor to House Beautiful, is filled with practical information for those who garden in containers and in city gardens.
"For 10 years," Druse writes, "I gardened in a place with winters as cold as Minnesota's and summers where reflected light and radiant heat made it feel like an Arizona desert." Druse's garden consisted of 100 plants growing on a rooftop in New York City. From Druse, you'll learn about lightweight pots and soilless mixtures.
Woods himself waxes lyrical on the goldenrods, asters, ironweeds, bonesets and other perennials we grow for fall color and garden interest.
If you want hot, vibrant colors in your garden in late summer and early fall, select asters, such as the New England (Aster novae-angliae) and New York (A. novi-belgii) asters. Here's a tip from Woods: You should pinch the New England asters back in early summer and midsummer to make them more compact. The New York asters grow smaller, and the yellow-centered flowers come in an array of purples, pinks and whites.
For less vibrant fall-bloomers, Woods recommends the white wood aster (A. divaricatus) and the prairie aster (A. ericoides), which has "clouds of tiny white flowers." Both will grow in poor, dry soil.
Our native goldenrods are also on Woods' favored list. If the taller species are more than you can handle in your garden, he suggests Solidago sphacelata Golden Fleece. It produces masses of golden-yellow flowers on three-foot stems. This plant should be available in local garden centers.
As in many other gardens, fall at Chanticleer is the season for dividing some perennials. Woods warns, however, that we should hold division of ornamental grasses until spring, so they have a warm season to grow into. He also suggests leaving tender plants, especially those with gray leaves, until spring. Make your divisions as early as possible, and water each new planting well after installation, to give the plants the best opportunity to put down new roots before frost.
As the leaves fall, Woods and his crew remove them from the lawns at Chanticleer and also from the perennial borders, to prevent them from forming heavy mats that suffocate plants. Many of the other cleanup duties, such as cutting back the frosted stems, he leaves until spring, because he likes the effect of the stems in winter.
When you have digested the information in "Perennials," you will be ready for Pamela J. Harper's elegant volume published earlier this summer, Designing With Perennials (Macmillan, $40). Harper also was raised in England. But 20 years of gardening and photographing plants and gardens in the United States have given her a broad perspective on the potential for perennials, and her pictures provide a wealth of design suggestions.
WHAT TO DO THIS WEEK
Hold off fertilizing trees and shrubs until late fall. If you fertilize now, you may stimulate late growth that will be damaged by frost.
When you remove crops from the vegetable garden, sow winter rye as a cover crop to hold the soil and provide additional organic matter to be turned next spring.