QBARS - v20n1 Rhododendrons in the Philadelphia Area

Rhododendrons in the Philadelphia Area
F. J. Sholomskas, Norristown, Pa.

In February, 1964, the Rhododendron Test Garden Committee (Sylvester F. Hubbard, Oscar F. Krebs and F.J. Sholumskas, Chairman.) of the Philadelphia Chapter of the American Rhododendron Society was assigned the task of rating rhododendrons with respect to both adaptability and quality in the Philadelphia area. This assignment led to questionnaires being sent out to the members of the chapter during the winter of 1964-1965. More than 100 questionnaires returned listed 169 hybrids and 33 species. These 202 plants were then rated on quality and adaptability, and comments were encouraged.
The report table is based on both average and median ratings for varieties that received five or more reports. In a group variety or species the ratings represent the better clones obtainable unless otherwise indicated.
The committee felt that it might be helpful to readers to indicate the number of recommendations that a plant received in addition to the number of growers reporting on that plant. Under "Reports," in the table, therefore, the first numeral represents the number of people recommending the plant as possibly the best in its class, while the second numeral represents the number of people reporting the plant. It was felt that these figures might prove to be helpful to someone interested in trying a particular variety.
Quality of bloom and plant are rated from 1 to 5; 1 would be the lowest 3 average, 5 the highest. The ratings will be expressed as fractions. The numeral above the line indicates flower quality, the numeral below the line the quality of the plant. No fraction given indicates insufficient experience with this variety in our area. Adaptability rating is from excellent to worthless. An excellent rating means that the plant will take considerable exposure in that zone; a good rating means that this variety does well in that zone if not given harsh exposure. Plants with ratings of fair or poor require considerable protection from wind and sun. If considerable variation in adaptability was reported this will be indicated by fair-good, poor-fair, etc.
Nearly all reports received could be filed as zone 7a U. S. D. A. Hardiness Map (average annual minimum temperature 0° to 5° F.) or zone 6b (average annual minimum temperature of -5° to 0° F.). In Pennsylvania the Schuylkill River can almost be considered the dividing line between the two zones. Northern Delaware and southern New Jersey are both in zone 7a.

Adaptability in
Variety (Color) Reports Quality Zone 6b Zone 7a Comments
A. Bedford (lav.- blue) 0-9 4/3 fair fair-good
Albert Close (pink) 0-14 3/3 good good
Album Elegans (white) 1-12 2/2 excellent excellent
Album Novum (white) 1-8 3/2 excellent excellent
Alice (pink) 0-7 worthless poor
America (red) 7-30 3/2 excellent excellent Fine truss
Amphion (rose) 0-6 3/2 fair good
Antoon Van Welie (pink) 0-6 poor poor
Arthur J. Ivens (pink) 0-9 3/4 fair-poor fair
Atroflo (rose-red) 2-20 4/3 fair-good good Heavy indumentum
Atrosanguineum (red) 0-13 2/3 good excellent
Augfast (blue) 0-6 poor fair
Azor (pink) 0-8 4/1 worthless poor
Bagshot Ruby (red) 1-8 3/2 fair good-fair
Beaufort (white) 0-19 2/3 good good Scented. Shy. Try sun
Beauty of Littleworth (white) 0-6 4/4 poor fair-poor
Belle Heller (white) 0-9 4/3 fair good-fair
Betty Wormald (pink) 0-9 4/3 worthless fair-poor
Blue Diamond (blue) 4-17 5/4 fair-poor fair-poor
Blue Peter (lav.-blue) 16-31 4/4 good good Highly recommended
Blue Tit (blue) 1-15 4/4 fair-poor fair-poor
Boule de Neige (white) 14-27 3/4 excellent excellent

Fine low white

Bow Bells (pink) 0-8 5/5 worthless fair-poor
Brandywine (rose) 1-6 4/2 fair good

See note 1 below

Britannia (scarlet) 0-10 4/4 poor fair-poor
Cadis (pink) 6-19 4/4 fair-good good Fragrant
Camich (purple-red) 0-11 1/3 good good
Candidissimum (white) 0-11 3/3 excellent excellent Slow to bloom
Caractacus (purp.-red) 1-16 1/3 excellent excellent
Carita (yellow) 0-11 4/4 poor fair-poor
Caroline (lav.-pink) 12-25 3/4 excellent excellent Scented flowers
Catawbiense Album (white) 10-19 3/3 excellent excellent Favorite tall white
Catawbiense Boursault  (lilac) 5-18 2/4 excellent excellent
Catawbiense Grandiflorum (lilac) 2-14 2/4 good excellent
C. S. Sargent (red) 1-8 3/3 good excellent Slow
Charles Bagley (red) 0-14 2/1 fair-good good
Charles Dickens (red) 0-12 2/2 excellent excellent Slow
Cheer (rose pink) 0-7 3/4 good good Blooms in fall
Chesapeake (apricot) 0-7 4/2 fair good See note 1 below
China (cream-yellow) 1-5 4/4 poor fair-poor
Chionoides (white) 1-11 3/4 good good
R. 'Conemaugh'
Fig.  11.  A plant of 'Conemaugh' blooming in the
garden of Cecil Smith, Aurora, Ore.
Cecil Smith photo
Adaptability in
Variety (Color) Reports Quality Zone 6b Zone 7a Comments
Conemaugh (lavender) 3-13 3/3 good good
Conewago (lav. rose) 9-22 3/2 excellent excellent
Countess of Derby 0-6 4/3 worthless poor
County of York (white) 7-22 4/3 good good Formerly 'Catalode'
Cunningham's White (white) 0-16 2/4 fair-good fair-good Blooms in fall
Cynthia (rose-red) 9-21 4/3 fair good Large model truss
Daphnoides (lilac) 1-7 2/4 good good Distinctive foliage
David Gable (pink) 8-15 5/4 good good One of the best
Delaware (apricot) 0-5 3/2 good good See note 1 below
Delicatissimum (white) 0-6 3/3 excellent excellent Slow to bloom
Disca (white) 0-16 4/3 poor-fair fair-good
Doncaster (red) 0-7 3/3 poor fair
Dr. Dresselhuys (red) 0-23 1/2 good good
Dr. Rutgers (red) 1-13 2/3 fair good
E. S. Rand (red) 0-13 2/3 fair-good good
Elizabeth (bright red) 0-9 4/5 poor poor
English Roseum (rose) 3-20 2/4 excellent excellent See note 2 below
Essex Scarlet (red) 0-7 4/1 poor-fair fair
Everestianum (lavender) 3-16 3/3 good excellent
Fastuosum Plenum (mauve) 0-13 3/3 poor-fair fair Double flowers
F. D. Godman (red) 0-8 2/3 fair-good good
Gloxineum (pink) 4-9 4/3 fair good
Goldfort (cream-yellow) 1-11 4/2 fair good
Goldsworth Yellow (yel.) 1-17 3/2 fair fair-good
Gomer Waterer (white) 5-16 3/4 fair fair-good Fine foliage
Gretchen (pink) 2-7 4/4 good good Hard to obtain
Harvest Moon (yellow) 0-7 3/3 poor poor-fair
Henriette Sargent (rose) 2-5 3/4 excellent excellent Hard to find
Hockessin (cream) 0-7 4/2 good good See note 1 below
Ignatius Sargent (rose) 5-17 3/2 excellent excellent Slightly scented
Jan Dekens (pink) 0-7 4/3 worthless poor
Jean Marie de Montague (red) 1-14 4/3 poor fair
Jock (pink) 0-7 poor poor
John Walter (red) 0-9 3/2 fair good
Kate Waterer (pink) 1-6 3/3 fair good
Kentucky Cardinal (red) 0-11 2/2 fair good
Kettledrum (red) 0-9 2/1 excellent excellent
King Tut (pink) 2-8 4/3 good excellent
Kluis Sensation (red) 0-7 poor
Lady Armstrong (pink 2-8 3/2 excellent excellent Slow
Lady C. Mitford (pink) 0-7 poor poor
Lee's Dark Purple (pur.) 1-20 2/3 good good
Lenape (yellow) 1-8 4/2 good good See note 1 below
Lord Roberts (red) 0-11 worthless poor
Luciferum (white) 0-6 3/3 good good Slow to bloom
Madame Carvalho (whi.) 0-6 2/3 fair good
Madame de Bruin (red) 0-18 3/2 fair-poor fair-good
Madame Masson (white) 1-12 3/2 fair good
Mars (deep true red) 6-19 4/3 fair-poor fair Hard to grow well
Michael Waterer (red) 0-6 2/2 fair fair
Montchanin (white) 0-7 3/2 good good See note 1 below
Moonstone (yellow) 0-9 5/4 poor poor
Mrs. B. Robertson (yel.) 1-7 4/3 fair fair
Mrs. C. S. Sargent (rose) 8-16 3/3 excellent excellent Well liked
Mrs. E. C. Sterling (pink) 0-6 poor fair
Mrs. Furnival (pink) 1-12 5/4 poor fair
Mrs. P. D. Williams (white) 2-13 4/3 poor fair
Mrs. R. S. Holford (salmon) 0-9 3/3 fair-good good

Adaptability in
Variety (Color) Reports Quality Zone 6b Zone 7a Comments
Mrs. W. R. Coe (pink) 6-11 5/4 fair good
Mucram (rose) 2-8 3/3 excellent excellent
Myrtifolium (rose) 1-12 2/4 good good Fine foliage
Naomi (pink) 0-10 4/4 poor fair
Nova Zembla (red) 9-22 3/4 excellent excellent Preferred as best
Old Port (plum) 0-6 1/3 good good
Parson's Gloriosum (lilac pink) 2-7 2/3 excellent excellent
Parson's Grandiflorum 0-6 2/3 excellent excellent
(rose purple)
Pink Pearl (pink) 0-13 worthless poor
Pink Twins (pink) 5-18 4/4 good good Hose-in-hose flowers
syn. 'Cathaem #4'
Pinnacle (pink) 2-6 4/3 good good
Pioneer (rose pink) 5-25 3/3 excellent excellent
P. J. M. (lavender) 2-13 3/5 excellent excellent Purple winter foliage
President Lincoln (lilac) 1-9 2/3 excellent excellent
Princess Elizabeth 0-6 4/2 fair good
(deep clear red)
Professor Bettex (red) 0-5 3/2 poor fair Difficult
Purple Gem (purple) 2-10 3/4 good good Needs sun
Purple Splendour (purple) 0-26 4/3 fair fair Difficult. Needs shade
Purpureum Elegans (purple) 0-9 2/3 good good
Purpureum Grandiflorum (purp) 1-8 3/3 good good
Ramapo (bright violet) 8-23 3/4 excellent >excellent Requires sun
Redhead (bright red) 0-13 4/1 fair fair-good syn. 'Atrier #10'
Robert Allison (pink) 4-12 5/3 fair-good good Blooms in June
syn. 'Gable's Pink #2'
Rosa Mundi (pink) 1-6 3/4 good good Blooms in April
Roseum Elegans (rose) 13-30 2/5 excellent excellent See note 2 below
Roseum Pink (rose-pink) 3-12 3/5 excellent excellent See note 2 below
Roseum Superbum (rose) 1-9 2/4 good good
Sapphire (blue) 0-5 poor
Sappho (white, dark eye) 0-12 4/2 fair-poor fair Exotic flowers
Scintillation (pink) 7-19 4/5 good good
Sefton (maroon) 2-9 3/2 good good Fine June bloom
Skyglow (pale apricot) 2-10 4/2 fair good formerly 'Dexter #9'
Trilby (red) 0-9 3/3 poor fair-poor
Unique (pale yellow) 0-14 3/5 fair-poor fair
Van Weerdon Poelman (red) 0-8 2/2 fair good
Vulcan (bright red) 3-13 4/4 fair fair-good
Westbury (pink) 1-7 4/4 good good
Wheatley (pink) 4-12 5/3 good good Lovely soft color
Wilsoni (rose) 6-15 1/5 good good Fine foliage, habit
syn. 'Laetivirens'
Windbeam (soft pink) 8-22 4/3 excellent excellent Well liked
Wissahickon (rose-red) 1-8 4/3 fair good
Wyanokie (white) 5-11 3/4 excellent excellent Fine
Zuider Zee (yellow) 0-5 worthless poor

Note 1: All the plants that had this comment are of the same parentage. All of these plants are rather similar especially in reference to their foliage and growth habits. While still young plants they are rather scrawny, but after about ten years they fill in nicely.

Note 2. It is said that about eight different clones are for sale as 'English Roseum', 'Roseum Elegans', and 'Roseum Pink'. It is evident that these names have been used inter-changeably by various nurseries. One form does exist that has soft rose-pink blossoms on a vigorous plant that has a superb habit and is easy to grow.

Adaptability in
Variety (Color) Reports Quality Zone 6b Zone 7a Comments

adenopodum (rose)





augustinii (blue) 0-8 worthless poor
brachycarpum (rose) 1-14 2/4 good good Very variable
campanulatum (mauve) 0-6 2/4 fair good Very variable
carolinianum (pink, mauve, white) 12-24 4/3 excellent excellent Variable. Best clones
are very fine
catawbiense (lavender) 1-10 2/3 excellent excellent Toughest of all
- Catalgla' (white) 3-5 4/2 excellent excellent Very fine bloom
- 'La Bar's White' 2-5 4/2 excellent excellent Pure white flowers
caucasicum (yellowish) 0-11 1/4 fair-good good
chapmanii (pink) 0-6 3/4 fair fair Variable
degronianum (rose) 4-9 4/4 good good Variable. Blooms Apr
discolor (white) 4-12 4/2 poor fair Blooms Jun-Jul, frag.
fargesii (pink, early) 0-7 4/3 poor fair Difficult
fastigiatum (purple) 1-9 4/4 good good
fortunei (blush, pink) 7-21 4/4 good good Fragrant. Variable
haematodes (red) 0-5 poor
hippophaeoides (rose) 0-14 3/3 good fair
impeditum (violet) 3-15 3/4 fair fair Difficult to please
keiskei, usual (yellow) 1-14 3/2 fair good Very variable
-dwarf form (yellow) 3-7 3/4 fair good
keleticum (rose, lavender) 1-6 4/5 good good Very promising
makinoi (pink) 5-17 2/4 fair good Long narrow leaves
maximum (white, pink) 4-15 1/3 good good Excellent in woodland
metternichii (rose) 5-13 4/4 good good
micranthum (white) 0-11 2/3 excellent excellent A novelty
minus (pink) 1-11 2/2 good good Very variable
mucronulatum (lay.) 1-17 3/3 excellent excellent Very early bloomer
-pink forms (pink) 4-8 4/3 excellent excellent
oreodoxa (pink) 0-5 4/3 poor poor Shy bloomer
racemosum (pink) 10-20 4/4 fair-good good Very fine
russatum (pink) 0-5 5/3 fair Difficult
smirnowii (lilac, pink) 0-15 2/4 good good Blooms in fall
sutchuenense (lilac) 0-6 4/5 fair fair Blooms in Mar-Apr
vernicosum (white, pink) 2-9 3/3 fair good
- Rock #18139 (apricot) 4-6 5/3 poor-fair fair-good
yakushimanum (pink) 9-17 5/5 good good Stands alone