LIGHT-FANTASTIC! PLUS AHS-MONTESSORI MEETING TWO NEW DEPARTMENTS American Horticultural Society The American Horticultural Society seeks to promote and recognize American excellence in horticulture across America. Horticulturist OFFICERS 1993-1994 Mrs. Sarah S. Boasberg Volume 73, Number 3 March 1994 Chairman Washington, D.C. Dr. William E. Barri€k ARTICLES First Vice Chairman Pine Mountain, Georgia Mrs. W.R.J. Dunn Light-Fantastic! First Vice Chairman Birmingham, Alah>ama At this time of year, as days lengthen and we fuss over tender seedlings Mr. Gerald T. Halpin while waiting for the sun's rays to rewarm the earth, it would be hard to Treasure. ignore the effects of light on our plants' health and vigor. As much as their Alexandria, Virginia need for wate!; a need for light in some amount is crucial to all plants. In this issue, we'll revisit the basics of photosynthesis and day length, consider BOARD OF DIRECTORS the role pigments play in plant growth, and look at plant shadows as Dr. Thomas Amason Birmingham, Alabama another aspect of gardening aesthetics. Mrs. Suzanne Frutjg Bale. Bronxville, New Yonk Mr. George C. Ball Jf. Leaves, Light, and Air .............. ....... .. ......... 8 West Chicago, Illinois Dr. Sherran Blair Long Night's Journey into Day .. ... ......... ... .. .. 9 Columbus, Ohio Mr. William F. Brinton Mount Vernon, Maine The Shadows Know . .. ... ................. 10 Mrs. Nancy H. Callaw~y Pine Mountain, Georgia Mr. Paul Ecke Jr. The Right Wavelength ..... .. .... ... .. ... ... ........... 12 Encinitas, California Dr. John Alex Floyd Jr. Birmingham, Alabama Emergency Flares .... ..... ...... .................... 12 Mrs. Julia D. Hobart Tr0y, Ohie Dr. Richard L. Lower Madison, Wiscensin DEPARTMENTS Mr. "lyin Md:}onald Houston, Texas In this issue we introduce two more new departments. "Plants and Your Mrs. Marryn L. Miller Ashton, Maryland Health" will cover a wide range of topics, from new discoveries about the Mrs. Walter M. Morgan, Jr. Nashville, Tennessee medicinal use of plants to the impact of gardening on our physical and Mr. Wuliam G. Pannill mental well-being-most often beneficial, but sometimes detrimental, as Martinsville, Virginia Mr. William A. Pusey when we sprain a muscle or encounter poison ivy. "Conservationists' Washington, D.C. Notebook" will look at efforts around the country to protect plants and Dr. Julia W. Rappaport Santa Ana, California their environments. Mr. Geoffrey L. Rausch PittSburgh, Pennsrlvania Mrs. Jane N. Scarff Plants and Your Health ........... .... .. ............ ..... 3 New Carlisle, Ohio Mrs. Josephine M. Shanks Housten, Tex:as Gardeners' Information Service . ......... .. ............ 4 Mr. Emanuel Shemin Greenwi·ch, Connecticut Mail-Order Explorer .............. ......... .. ..... .. ... 6 Mr. Andre Viette Fishersville, Virginia Ms. Katy Moss Warner Conservationists' Notebook ..... .. ........ ........ .. .... 7 Lake Buena Vista, Florida Mr. Monroe Whitton Alexandria, Virginia AHS Bulletin Board .............. .. .. ........... .. .. 14 Book Catalog ....... ........... ..... .. ............ 18 PRESIDENT Dr. H . Marc Cathey Regional Happenings 20 EXECUTIVE VICE PRESIDENT Classified 22 Mrs. Helen Fulcher Walutes News Briefs 24 2 March 1994 American Horticulturist PLANTS AND YOUR Editor Kathleen Fisher Managing Editor HEALTH Mary Beth Wiesner Assistant Editor C hris Bright Editorial Assistant Steve Davolt Silk Purslane or Sow's Ear? ing Roche beta-carotene tell us that 50 Membership Director milligrams every other day will prevent the Darlene Oliver If you garden, yo u're probabl y growing second heart attack," says Duke, referring purslane---whether you like it or not. Most to a formulation from the giant drug com­ gardeners don't, but it's nea rl y impossible pany. "One cup of dry purslane contains Editorial Advisory Board to uproot all those flat clumps of succ ulent, nearly 10 times that amount." Dr. Gerald S. Barad Vitamin E, beta-carotene, and some of Flemington, New Jersey reddish stems with their tiny spoon-shaped John Bryan leaves. In his famous ga rdening encyclope­ purslane's other components are anti-oxi­ Sa usa liro, Ca lifornia John Creech to dia, Donald Wyman called Portulaca dants. These reduce our exposure free Hendersonville, North Carolina oleracea "probably the worst weed trou­ radicals-charged particles that damage Keith Crotz bling all gardeners throughout the U.S. and cell membranes and may ca use cancer. Chillicothe, Illinois Panayoti Kelaidis Canada." The World's Worst Weeds, a sur­ Anti-oxidants help purslane succeed as a Denver, Colorado vey published in 1977, celebrates purslane weed: they disarm many herbicides. Peter Loewer As hevill e, North Carolina as an international agricultural nuisanc e. Perhaps the most remarkable ingredient Janet M. Poor But James Duke, an ethnobotanist with the in purslane's chemica l makeup is nor-epi­ Winnetka, Illinois Dr. James E. Swasey U.S. Department of Agriculture and an nephrine, a stimulant of the adrenal glands. Newark, Delaware authority on edible wild plants, sees purs­ Duke knows of no other readily ava il able lane as a weed with potential. edible plant that contains the chemical. Duke explains that purslane has long Nor-epinephrine is used to treat shock; for Advertising had a role in the pharmacopoeias of other instance, it's the acti ve ingredient in the bee AHS Advertising Department 2300 South Ninth Street, Suite 501 cultures. The Chinese use it to treat a host sting kits used by people with severe aller­ Arlington, VA 22204-2320 of ailments, including anthrax, herpes, gies to insect venom. (703) 892-0733 snake-bite, and tumors. In India, purslane Duke isn't unreservedly enthusiastic about Printer is prescribed for piles, asthma, and leprosy. purslane's culinary potential. If you decide to William Byrd Press, Inc. Native American cultures have resorted to regard this year's purslane as a crop instead it for earache, burns, and worms. of a weed, he recommends eating young Now mainstream medicine is taking an shoots as a salad green or cooked like spin­ Replacement issues of AMERICAN HORTICULTUR­ interest in purslane as well, because the plant ach; the older ones can be fibrous. He de­ IST are available at a cos!: of $2 per copy. The opinions expressed in the articles that appear in AMERI CAN was found to contain very high levels of scribes the potherb as tasting like "slimy HORTICULTURIST are 'hose of rhe au rh ors and are omega-3 fatty acids. Best known as constitu­ spinach." To improve the texture he suggests not necessarily those of the Sociery. Botanical nomen­ claru re in AMERICAN HORTICULTURIST is based ents of fish oils, omega-3s are thought to adding egg and breadcrumbs or using purs­ on HORTIJS THIRD. Manuscripts, art work, and greatly reduce the harmful effects of choles­ lane in soups, "where the mucilaginous tex­ photographs sem for possible publication will be re­ turned if they are accompanied by a self-addressed, terol. Some nutritionists believe omega-3s can ture might be appreciated." stamped envelope. We cannot guarantee the safererurn help fight a vast assortment of other ills too, Duke cautions against becoming a of unsolicited material. including acne, herpes, schizophrenia, obe­ "purslamaniac." All edible higher plants AMERICAN HORTICULTURIST, ISSN 0096-4417, is tne official publication of the American HortiGuirurai sity, and cancer. Duke says omega-3s consti­ probably contain some valuable nutri­ Society, 7931 East Boul evard Drive, Alexandria, VA tute about 8 percent of purslane's ents-beta-carotene, for instance, 22308·1300, (Y03) 768-5700, and is issued 12 rimes a year. The American Horticultural Society is a n0nprofit dried weight-a higher concen­ is only one of some 500 carot­ organizatieo dedicated to excellence in hor:ricu lture. tration than known in any other enoids that plants produce. Membership in the Society includes a subscription to AMERICAN HORTICULTURIST. Narional member­ leafy vegetable. Many of these may playa role in ship dues are $45; rwo years are $80. Foreign dues are Purslane has other assets. "It's human nutrition too. So eat $60. $15 of dues are designared for AMERICAN HORTICULTURIST. Copyrighr © 1994 by rhe Amer­ one of the best sources I know of widely in the plant kingdom, or ican Horticultural Society. Second-class postage paid for tocopherol (vitamin E)," says as Duke likes to say, "moderation at Alexandrja. Virginia, and at additional mailing of­ fi ces. Posrmasrer: Please send Form 3579 ro AMERI­ Duke. "The USDA recently said it's virtu­ in all things except variety." -Chris Bright CAN HORTICULTURIST, 7931 Easr Boulevard ally impossible to get 20 milligrams of Assistant Editor Drive, Alexandria, VA 22308-1300. tocopherol without supplementing. A cup of dry purslane could contain more than Duke's Handbook of Edible Weeds is Produced in U.S.A. 200 milligrams." Purslane also has large available at for $21.20 from the American amounts of beta-carotene. "Doctors push- Horticultural Society Book program. AMERICAN HORTICULTURIST 3 GARDENERS' INFORMATION SERVICE Q: Gypsy moths have killed many of grass clippings, moss, a bandoned nests, and artemisia. Other choices among herba­ the trees in my neighborhood. Before I and dead limbs. ceous flowering plants might be annual begin to replant, can you tell me what trees Conifers are especially fire-prone and wildflowers such as poppies, lupines, tidy­ are resistant to gypsy moths? -F. D., should probably be avoided unless you tips, clarkias, phacelias, or perennials such Springfield, Pennsylvania have a very big lot. Keep the limbs of any as daylilies, red-hot poker (Kniphofia uva­ trees 15 to 20 feet apart to avoid creating ria), agapanthus, sea pinks (Armeria mari­ A: According to Diane Relf, an exten­ a continuous canopy that would allow fire tima), and penstemons. sion specialist in the horticulture depart­ to spread easily from tree to tree. To keep For more information, contact the The­ ment at Virginia Polytechnic Institute, the grass fires from spreading into trees, prune odore Payne Foundation: 10459 Tuxford following are the gypsy moths' least pre­ out all limbs within 15 to 20 feet of the Street, Sun Valley, CA 91352.