FOUR SEASONS NfNAJ~ GREEN HOUSE! THE ONLY "FOLDING" PORTABLE GREENHOUSE IN AMERICA Optional: (Sold. separately) Planting tables, heater, thermostat, exhaust fan , thermometer. -------------------- - ---------------, Manufactured and distributed by Namae _____________________ I Horticulture Division of Please send free literature, specs, and I prices. I am interested in the following: Addressi __________________ I PRINCESS MODEL #GH873 I 4ris PRODUCTS, INC. D (Nine-Foot Dia.) .......... $345 City' _________State' ____..L.Zip, ___ I 32401 North Avis Drive DUCHESS MODEL #GH1073 I Madison Heights, Michigan 48071 D (Eleven-root Dia.) . ...... $595 o Check enclosed Card expiration date I Tel. No. (313) 583-1400 QUEEN MODEL #GH1273 o ~v1astercharge 11,__ - ____________ I D (Thirteen-Foot Dia.) ..... ... $795 Copyright Avis Products, Inc. 1973 Plus tax where applicable. Shipped prepaid. o BankAmericard #-______________ I Covered by U. S. Patent No. 3,333;373 I the supefnatural organic fertilizer! What do we add to Milorganite? Nothing! Everything's already there - naturally! an editorial . .. Horticultural Breadth and Depth Gardeners are ecologists. Th e man, woman, or child that are new, at least, new to us. w ith a hoe makes hi s immediate environment better; better to Have you ever grown Tri cyrtis hirta? It is a charming little look at, more productive. Ga rd eners have a creative bent. lily-like affa ir with w ide, funnel-shaped, speckled w hite Thi s plant lover grows nice beds of flowering ann uals while flowers. It is hard y to -100 F. Seed is li sted in the 1973 hi s neighbor grows bonsai trees and the lady across the way A.H.S. seed distribution li st. O r Gladiolu s tristis, that delicate, has assembled a fine coll ectio n of potted exotics with wh ich flaired floret species from Natal that has to come indoors over she decorates her home. You are reading this magazine be­ winter in the north but which stays out in southern gardens? cause you fit into th at category w hi ch the American Horticu l­ It, too, is an A. H .S. offering. Seed lists and specialty cata logs tural Society intends to serve-advanced amateur gardeners. abound in uncommon or unfamiliar species. Let's look into It is our goal to suppl y you w ith reading material that w ill th ese . make you stretch. American ga rd eners need to expand their What do you do when somebody hands you a packet of ecological range; their creativity needs refining to make it seeds or a living plant of a species you never have grown more meaningful. It's no good read ing more about marigold before? You can 't just stick it in somewhere and hope for the germination or taking geranium cuttings. These are amateur best. Better consult a fi rst rate garden encyclopedia-it st ill is techniques. But wait. What about the refinements of marigold hard to beat L. H . Bailey' s The Standard Cyclopoedia of breeding; the genetics, cytology, and so on? What about Horticulture-and fi nd out about that plant. Sun or shade? Is ca llus formation of cuttings, the chemistry of rooting horm one the best so il humusy or gritty, neutral or acid, moist or fast­ functions, and other aspects of events in the sequence from draining? W hat about w inter hardi ness? The point is, you cutting to new plant? Don' t you w ish to know about these need to know. And in getting to know, you refine your horti­ things? cultural expertise. American horticulture tends to stay at a fairly superfi cial When each of us polishes hi s ga rd en in g know-h ow, leve l, on the average. You would not believe that if you vis­ American horti cu lture benefits. As we demand someth ing in ited horticultural " hot spots" such as the Pacific Northwest or our seed ca talogs beyond forty se lections of marigolds, un­ Lake Cou nty, Ohio; or if you attended conventions of th e common but desirable ornamentals w ill be made avai lable. specia lty plant societies. Nevertheless, it is tru e. Yea r after As members of A. H .S. you and I have something to li ve up to; year one reads in house ho ld magaz in es how to keep the our Society now owns a beautiful eightee nth century house Christmas poinsettia from one season to the next, kalanchoe ca ll ed Wellington sited on the George Washington Ri ve r ditto, and what about that Dieffenbachia that has been dying Farm. One of these days that property w ill be a horticultural in tens of thousands of overheated, ari d livi ng rooms over mecca. Wasn't it Oscar Wilde w ho sa id that he had to live up America fo r decades? Let' s sta rt a new trend. Let's b ri ghten to his fine porcelain dishes? O ne of these days we w ill have o ur envi ronment w ith a plant we never have see n before. to li ve up to the gardens at the River Farm. Let' s put some 2 Let's expand o ur creative palette, adding colors and textures breadth and depth into American horticu lture.-J. P. B. American HCDrticulturist Volume 52 Number 2 Summer 1973 JOHN PHILIP BAUMGARDT, Editor The American Horticultural Society, Publisher For United Horticulture . .. the particular Mount Vernon, Virginia 22121 objects and business of Th e America n O. KEISTER EVANS, Executive Director Horticultural Society are to promote and encourage national interest in scientific resea rch and education in horticulture in all of its branches. AMERICAN HORTICULTURIST is the offi­ cial publication of The Ameri can Horti­ IN THIS ISSUE cultural Soc iety and is iss ued in March, June, September, and December of each 2 Editorial yea r. Thi s magazine is included as a ben­ 26 Twenty-eighth Congress of The American Horticultural Society. efit of membership in Th e American Horti­ 31 A Fine (certified) Summer Afternoon---..iames A. Fanning . c ultural Soc iety. Ind ividual dues are $15.00 a year. Refer ed itorial matters to: John Philip Baumgardt Education Ameri can Horticulturist 18 People-Plant Interacti on-a new horticultural perspective-Charles A. Lewis P. O. Box 7163 25 A.H.S. Program in People-Plant Interaction Kansas City, Missouri 64113 Refer advertising matters to: Publisher Services, Inc. 62 1 Duke St reet Gardener's Notebook Alexa ndria, Virg inia 223 14 8 Gulf Coast Gardening Notes from The Garden Show WYES TV-Mrs. Lucius Address requests for reprints of Mirabeau Lamar articles to The American Horticultural Society, Mount Vernon , Virginia. AMERICAN HORTICULTURIST is de­ Gardening Arts voted to the dissemination of knowledge 38 Ground Covers-labor saving plants-Harold Epstein in the science and art of growing orna­ mental plants, fruits, vegetables , and re­ lated subjects. Original papers which in­ c rease knowledge of plant materials of Hort-Science economic and aest heti c importance are 10 Maples of Japan---..i. D. Vertrees invited . For manuscript specificat io ns plea se add ress the Executive Director, Mount Vernon , Virginia 22 121 . Misunderstood Plants Replacement issues of AMERICAN HOR­ 4 Weed Trees in the City-horticultural derelicts or unsung heroes?-Russell A. TIC U LT URIST are avai lable at a cost of Beatty $2.50 per copy, but not beyond twelve months prior to date of current issue. The opinions expressed in the articles which appear in AMERICAN HORTICUL­ Research Report TURIST are those of the authors and are 34 Late Summer Injury of Korean Rhododendron-Alfred J. Fordham not necessari ly those of the Society. Th ey are presented as contributions to contem­ porary thought. Sub-Tropica I 15 Horticulture in New Orleans-Tom E. Pope and Ola Mae Word Seco nd class postage paid at Alexandria, Virginia and at add itional mailing offices. OUR COVER PHOTO-Sun-dappled walks and avenue bordered by broad-crowned live Copyright © 1973 by The American Horti­ oaks dripping Spanish-moss, these are the key characters of gardens in the deep South. cu ltural Society. This photograph was taken at Rosedown Plantation. 3 shrubs grew undisturbed, lower shade­ loving plants returned, birds brought in seeds from other gardens and neighbor­ hoods and the whole garden developed into a strange mixture of horticultural " roughnecks" . They competed with each other, lived on little nourishment and adapted to the city environment very much like the street gangs of the inner city. Who are some of these" Dead End Kids" of yesterday' s gardens? Of cou rse , the cast varies from region to region, but a few characters stand out clearly. The star (or villain) must surely be the dreaded tree-of-heaven (Ailan­ thus altissima).**Another tree frequently found especially in California is the rugged black locust (Robinia pseudoa­ cacia) defying all to climb its thorny limbs. The white poplar (Populus alba) sends out its sprout-producing roots searching for water, creating new trees along the way. The less invasive rela­ tive, lombardy poplar (Populus nigra 'Italica') occasionally is found. Other frequently found city trees are the silver maple (Acer saccharinum), common hackberry (Celtis occidentalis), plum WEED TREES in the CITY seedlings (Prunus sp .), and the vora­ cious siberian elm (Ulmus pumila). In horticultural derelicts or unsung heroes? milder climates such as California we find the black acacia (Acacia melanoxy­ Ion), blue gum (Eucalyptus g/obulus), Rus sell A. Beatty* si Iver wattle (Acacia decurrens ' Deal­ bata') and a number of other imported Mulberry, green ash, soft maple, Have you ever poked through an exotics.