TIIE NA.TIONA.L ~G.A.ZINE J0 URN AL 0F THE AMER I CAN H0 RIle UL T U R A LSD ClET Y, INC. * July 1957 Please add,'ess all c01nmul'licat·iolls to THE AMERICAN HORTICULTURAL SOCIETY, INC. 1600 Bladensburg Road, Northeast Washington 2, D. C. OFFICERS President: Mr. Stuart M. Armstrong, Silver Spring, Maryland Fill'St Vice-Pl'esident: Dr. Henry T. Skinner, Washington, D.C. Second Vice-Presiden.t: Mrs, Walter Douglas, Chauncey, New York S ecretary: Mr. E uge1'le Griffith, Takoma Park, Maryland TreasuIYel': Miss Olive E. Weather ell, Olean, New York Editor: Mr. B. Y. Morrison, Pass Christian, Mississippi Managing Editor: Mr. James R. Harlow, Quinque, Virginia Editol'ial Staff: Miss May M. Blaine, Washington, D. C. Mr. Bernard T . Bridgers, Washington, D. C. Art Editor: Mr. Charles C. Dickson, Kensington, Maryland DIRECTORS T erms Expiring 1958 Terms E-~piri'l~g 1959 Mr. Stuart Armstrong, Silver Spring, Mary- Dr. Donovan S. Correll, Renner, Texas land Dr. Frederick W. Coe, Bethesda, Maryland Dr. J ohn L. Creech, Glenn Dale, Maryland Miss Margaret C. Lancaster, Takoma Park, Mrs. Peggie Schulz, Minneapolis, Minnesota Maryland Dr. R. P. White, Washington, D. C. Mrs. Frances Patteson-Knight, McLean, Mrs. Harry Wood, Swarthmore, Pennsyl­ Virginia vama Dr. F reeman A. Weiss, Washington, D.C. DIRECTORS EMERITUS Mrs. Robert Woods Bliss, Washington, D. C. Mrs. J . Norman Henry, Gladwyne, Pennsylvania Mrs. Mortimer J . Fox, Mt. Kisco, New York Mrs. Arthur Hoyt Scott, Wallingford, Pennsylvania HONORARY VICE-PRESIDENTS Dr. A. S. Crafts Mrs. Martha F. Maxwell American Society of Plant Physiologists Epiphyllu1n Society of A1'I1.e1'ica University of California 500 Grove Place Department of Botany Glendale 6, California Davis, California Dr. Dwight M. Moore Mr. Harry W. Dengler A1l~e1'ican Fern Society Holly Sl)ciety of Ame1'ica University of Arkansas Maryland Extension Service Department of Botany and Bacteriology Co llege Park, Maryland Fayettevill e, Arkansas Dr. Freeman S. H owlett Mr. W. D. Morton, Jr. American Society for Horticultural S cience A111el'ica1~ Amaryllis Society The Ohio State University 3114 State Street Drive Department of Horticulture and Forestry New Orleans 25, Louisiana Wooster, Ohio Miss Gertrude M. Smith Mrs. Roy Arthur Hunt Joh1~ f. T yler Arboretum Gal'den Ch£b of America Lima, Middletown Township 4875 Ellsworth Avenue Delaware County, Pennsylvania Pittsburgh 13, Pennsylvania Dr. Donald P . Watson Mr. Woodson K. J ones American H01,tic~dtura l CMlncil Men's Garden Clubs of America Michigan State University 1827 Devine Street Department of Horticulture Jackson 2, Mississippi East Lansing, Michigan The National Horticultural M,agazine VOL. 36 Copyr ight, 195 7, b)' THE AMERI CAN HORTICULTURAL SOCIETY, I:src. No. 3 JULY 1957 CONTENTS , • < Fig Trees ./or Ornamental Planting. IRA J. CONDIT ____ _____________________ _______ ._ .. 253 Longwood Gardens. W. H. HODGE _________ . ______________________ ________________ .______ ._________ 260 Hydrangeas. ELIZABETH ::\1CCLINTOCK ___ ___________________ . ___________ __ ______ . _________________ 270 .) American RllQdociendron Society T est Gardens- PortJa~d , Oregon. C. 1. SERSANOUS ___________________________________________________________ 280 Oxalis n lbra. _IV ALTER C. BLASDALE ________________________________________________________________ 285 Chunnenuggee Horticultural Society and Public Gardea. L UCILE CARY LOvVRY__________ ____ ____________________________________________ 289 Dwarf Azalea Hybrids. ROBERT L. PRYOR .____________ __ ___ ____________ __ ________ ___ __ ____ --r- 295 The Lightest IV00d. EDWIN A. MENNINGER __________________________________________ ___ _._ 302 Recent R esearch Results. DO NA LD P . Vi ATSO N________________________________________________ 305 A Book or Two___________________ __________________________________________________________________________________ 308 The National Horticultural Magazine The National Horticultural Magazine is a quarterly journal, being the official publication of The American Horticultural Society, Incorporated. It is devoted to the dissemination ot knowledge in the science and art of growing ornamental plants, fruits, vegetables, and related subjects. The Journal is printed by Monumental Printing Company at Thirty-second Street and Elm Avenue in Baltimore, Maryland, and is entered as second class matter in the post office of. that city in accordance with the Act of August 24, 1912. Additional entry for Washington, D. c., was authorized July 15, 1955, in accordance with the provisions of Section 132.122, Postal Manual. Subscription to the J oumal is included in membership, which is $5.00 a calendar year. 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Reprints, saddle-stapled, will be furnished in accordance with the following schedule of prices, plus postage, and should be ordered at the time gall ey proof is returned by the author: Copies 2pp 4pp 8 pp 12pp 16 pp Covers 100 $ 6.60 $12.10 $25 .30 $36.30 $47.30 $12.10 Additional 100s 1.65 1.87 3.30 5.06 6.05 1.65 The Journal is issued for the quarters commencing with January, April, July, and October. Manuscripts must reach the Editorial Office at the Society's Headquarters three months before publication is desired. Miss ing numbers will be replaced without charge prov ided claim is received in the Editorial Office within thirty days after publica ti on date. Fig Trees for Ornamental Planting IRA J. CONDIT The genus Ficus, with its eighteen tures clown to about 25 ° Fahrenheit: F. hundred species, shows a greater diver­ maC1'ophylla, F. co lwnnal'is, F. Tubigi­ sity of woody shrubs, vines, and trees nosa, F. ova to, F. platypoda petiolaris, than that of almost any other genus of F. watkinsiana, and F. mysorensis. F. plants. Scattered as they are throughout retusa needs protection if temperatures tropical and su btropical cou n trie , the drop to 25 °. F. plt7nila on walls is hardy diverse [arms have been utilized in many except for tender tip , at considerably ways, the fruit for food, the bark for lower temperatures . On the other hand, paper, the leaves for fodder, the latex F. ben/amino and F. elastica are likely for rubber and for medicine, the wood to be injured by three or four degree for timber, and many for ornamental of frost. planting. As ?vlary Barrett reports, some spe­ It is not the province of this article cies may be killed to the ground by a to discuss such subjects as the botanical heavy frost but trees are renewed from characters which distinguish members of the base. This ha occurred at the Hunt­ the genus from other plant, the kinds ington Botanical Garden in California or location of fig' flowers, nor the rela­ with F. cajJensis and F. than ningii. F. tion of insects to pollination of the pis­ lyrata growing in a canyon near Lo~ tillate flowers. These are covered in d e­ Angeles was frozen almost to the ground tail by many other "vriters, among them by a temperature down to 27 °. At the being Lyon (1922), Williams (1928), same place F. elastica uffered injury at Burkill (1935) , Nehrling (19<J.2) , Cor­ 27 ° while another tree on a higher lo­ ner (1952). and Barrett (1956). This cation was not injured. Trees of F. race­ article deals only 'with the species of mosa and of F. gnaphalocarpa on a hill­ Ficw which are planted for ornamental side at Riverside, California, were froz­ purposes, taking up first their hardiness I ~n to the ground at about 25° but suck­ and methods of propagation, then a ers soon sprouted from the base. Bank­ discussion of those which grow as vines, ing soil around the trunk early in the as pot plants, as avenue or street trees, season will serve as protection and pre­ and as iNdividual specimens. vent the total loss of specimen trees. H aTdiness Nlethods of Propagation Most species of the genus Ficw are Most species of Ficus can be readily native to tropical or subtropical cli­ grown from soft-wood cuttings if these mates aIld are not hardy in the orcli­ are secured from plan ts under lath or nary sense of the term. Some are decid­ glass cover. Cu ttings from outdoor trees uous or partly so and may thus escape on the other h and are often difficut to seasonal frost damage.