QBARS - v15n4 Summary of Replies to Questionnaire on the Best Rhododendrons, Azaleas and Methods of Cultivating Them in the Region Served by the Great Lakes Chapter
Summary of Replies to Questionnaire on the Best Rhododendrons, Azaleas and Methods of Cultivating Them in the Region Served by the Great Lakes Chapter
David G. Leach
EXPLANATORY NOTE: In attempting to tabulate the replies to the questionnaires which were distributed a few months ago it soon became apparent that the climate extremes within our region made it imperative to classify the information according to the climate from which it came. Accordingly, the completed questionnaires were divided into two groups: those represented by zone 5b on the new plant hardiness zone map of the U. S. Department of Agriculture, and those which came from zone 6b of the new map, which is much more accurate than the old.
Zone 5, then, as it is used below, is the "inland" region, 10 miles or more away from the Great Lakes, in New York, Pennsylvania (excluding Allegheny and Cambria counties), Ohio and southern Ontario. In Michigan it refers to the inland communities south of Port Huron but also to the lake shore area north of Port Huron.
Zone 6 includes the regions within 10 miles of any of the Great Lakes (except north of Port Huron in Michigan) plus Allegheny and Cambria counties in Pennsylvania.
The reports seem to come clearly from one zone or the other, and the arbitrary selection of a 10-mile limit from any of the Great Lakes appears to apply quite well for this purpose.
This information should be of great value to our members and all are urged to preserve this report as a guide in purchasing Rhododendrons and Azaleas and in their cultivation of these plants. I have taken an editor's privilege of inserting comments in cases where the tabulation of the data alone does not reveal all of the useful information derived from it. Such comments are clearly identified in each case.
The response to the questionnaire was gratifyingly large and reflected the cooperation and enthusiasm of our members which we have come to regard as a permanent characteristic of the Great Lakes Chapter.
| RHODODENDRONS GROWN | |||||
| Average Bud Hardiness |
Average
(mathematical) % of sun best results |
||||
|
HYBRIDS |
Ratings | Zone 5 | Zone 6 | Zone 5 | Zone 6 |
| 'A. Bedford' (lavender-blue) | H-3 xxx | Good | 65% | ||
| 'America' (red) | H-1 x | Good | Good | 60% | 75% |
| 'Arthur J. Ivens' (rose) | H-2 xxx | Good | 75% | ||
| 'Beaufort' (white) | Good | 50% | |||
| 'Belle Heller' (white) | Fair | 75% | |||
| 'Besse Howells' (purplish rose) | Good | 75% | |||
| 'Blue Peter' (lavender-blue) | H-2 xxx | Fair to Good | Fair to Good | 45% | 55% |
| 'Blue Tit' (blue) | H-3 xxx | Good | 70% | ||
| 'Boule de Neige' (white, early) | H-1 x | Good | Good | 55% | 80% |
| 'Britannia' (scarlet) | H-3 xxxx | Poor | Fair to Good | 50% | 65% |
| 'Caractacus' (purplish red) | H-1 x | Good | 55% | 75% | |
| 'Caroline' (pale lavender) | Good | Good | 45% | 60% | |
| 'Catalode' (white) | Fair | 75% | |||
| 'Catawbiense Album' (white) | H-1x | Good | Good | 75% | 90% |
| 'Catawbiense Boursault' (lilac) | Good | Good | 80% | 75% | |
| 'Catawbiense Grandiflorum' (lilac) | H-2 x | Good | Good | 80% | 80% |
| 'Charles Bagley' (red) | H-2 x | Fair | 50% | ||
| 'Charles Dickens' (red) | H-1 x | Good | 50% | ||
| 'Chesapeake' (white) | Good | 75% | |||
| 'Conemaugh' (pink, early) | H-2 xx | Good | 65% | ||
| 'Conewago Improved' (pink, early) | H-2 xx | Good | 60% | ||
| 'C. W. Sargent' (red) | Fair | 70% | |||
| 'Cunningham's White' (white) | H-2 x | Poor | Good | 75% | 80% |
| 'Dr. H. C. Dresselhuys' (red) | H-2 o | Fair | Good | 60% | 85% |
| 'Dr. H. J. Lovink' (red) | H-2 o | Good | 80% | ||
| 'Dr. V. H. Rutgers' (red) | H-2 x | Poor | Good | 50% | 85% |
| 'Edward S. Rand' (red) | H-2 o | Poor | Fair | 50% | 65% |
| 'English Roseum' (purplish rose) | Good | Good | 75% | 80% | |
| 'Everestianum' (lilac) | H-2 x | Good | Good | 75% | 80% |
| 'Fanfare' (scarlet) | Good | 75% | |||
| 'Goldsworth Yellow' (apricot-yellow) | H-2 xx | Poor | Good | 50% | 70% |
| 'Gomer Waterer' (blush) | H-2 xx | Fair | Fair to Good | 40% | 80% |
| 'Ignatius Sargent' (rose) | H-1 x | Good | Fair | 65% | 75% |
| 'John Walter' (crimson) | H-2 x | Poor | Good | 40% | 65% |
| 'Kluis Triumph' (dark red) | Good | 80% | |||
| 'Lady Eleanor Cathcart' (pink) | H-2 xx | Poor | 50% | ||
| 'Lady Primrose' (pale yellow) | H-3 xxx | Poor | 50% | ||
| 'Lee's Dark Purple' (purple) | H-2 x | Fair | Good | 50% | 80% |
| 'Madame Carvalho' (white) | H-2 o | Good | 85% | ||
| Madame Masson' (white) | H-2 x | Good | 85% | ||
| 'Mars' (deep red) | H-2 xxxx | Poor | Fair to Good | 40% | 60% |
| 'Maximum Roseum' (pinkish lilac) | Good | 85% | |||
| 'Michael Waterer' (dark red) | H-2 x | Good | 65% | ||
| 'Moser's Maroon' (red-maroon) | H-3 x | Good | 65 % | ||
| 'Mrs. C. S. Sargent' (rose) | H-1 x | Good | Good | 75% | 85 % |
| 'Mrs. P. D. Williams' (white) | H-2 xxx | Good | 80% | ||
| 'Nova Zembla' (red) | Good | Good | 50% | 75% | |
| 'Parsons Gloriosum' (pinkish lilac) | Good | 80% | |||
| 'Parsons Grandiflorum' (purplish rose) | H-1o | Good | 80% | ||
| 'Pink Cameo' (pink) | Good | 75% | |||
| 'Pinnacle' (pink) | Good | 75% | |||
| 'Pioneer' (rose, early) | Fair to Good | Fair to Good | 50% | 75% | |
| 'Praecox' (rosy lilac, early) | H-3 xx | Good | 80% | ||
| 'Princess Elizabeth' (crimson) | H-2 xx | Poor to Fair | Good | 55% | 80% |
| 'Professor F. Bettex' (red) | H-2 x | Good | 85 % | ||
| 'Purple Splendour' (dark purple) | H-2 xxxx | Poor | Poor to Fair | 45% | 60 % |
| 'Ramapo' (lavender-blue, dwarf) | Good | Good | 75% | 75% | |
| 'Roseum Elegans' (rosy lilac) | H-1 x | Good | Good | 80% | 80% |
| 'Roseum Superbum' (purplish rose) | H-2 o | Good | 80% | ||
| 'Satin' (pink) | Good | 75% | |||
| 'Sefton' (reddish purple) | 75% | ||||
| 'Souvenir de Dr. S. Endtz' (rose-pink) | H-3 x | Good | 65% | ||
| 'Sappho' (white) | H-2 xx | Fair | 50% | ||
| The General' (red) | Good | 75% | |||
| 'Van Weerden Poelman' (red) | Good | Fair to Good | 75% | 60% | |
| 'Vernus' (pink, early) | Fair | 75% | |||
| 'Vulcan' (red) | H-3 xx | Fair | 50% | ||
| 'Wilsoni' (Laetevirens) (lavender-pink) | Good | 50% | |||
| 'Windbeam' (white) | Good | 75% | |||
| Westcroft hybrid #1019 | Good | 80% | |||
| RHODODENDRONS GROWN | |||||
| Average Bud Hardiness |
Average
(mathematical) % of sun best results |
||||
| SPECIES | Ratings | Zone 5 | Zone 6 | Zone 5 | Zone 6 |
| brachycarpum (white, late) | H-2 x | Good | Good | 75% | 80% |
| carolinianum ("Punctatum"), (pink, early) | H-2 xx | Good | Good | 80% | 90% |
| catawbiense (lavender) | H-1 x | Good | Good | 80% | 80% |
| 'Catalgla' (superior form of catawbiense var. album) (white) | Good | Good | 80% | 80% | |
| caucasicum (ivory) | H-3 x | Poor | 75% | ||
| discolor (white or pink, late) | H-3 xxx | Poor | Fair to Good | 40% | 50% |
| fortunei (blush, early) | H-2 xxx | Fair | Good | 40% | 50% |
| hippophaeoides (violet-blue, dwarf) | H-3 xxx | Good | 75% | ||
| impeditum (violet-blue, dwarf) | H-2 xxx | Good | 65% | ||
| keiskei (yellow) | H-2 xxx | Poor | 65% | ||
| makinoi (pink) | H-3 xx | Poor to Fair | 75% | ||
| maximum (white or pink) | H-1 x | Good | Good | 40% | 65% |
| micranthum (white) | H-1 x | Good | Good | 70% | 75% |
| minus (pink, late) | H-2 x | Good | Good | 80% | 80% |
| mucronulatum (lavender pink, very early) | H-2 xx | Good | Good | 90% | 90% |
| racemosum (pink, dwarf) | H-2 xxxx | Poor | Fair | 50% | 70% |
| russatum (blue, dwarf) | H-2 xxx | Poor to Fair | 65% | ||
| smirnowii (lavender) | H-2 x | Fair to Good | Fair to Good | 75% | 80% |
| wardii (yellow) | H-4 xxxx | Poor | 75% | ||
The ratings following the color descriptions of both hybrids and species are those of the American Rhododendron Society as published in Rhododendrons 1956 as follows:
| HARDINESS RATINGS | MERIT RATINGS |
| H-l: Hardy to -25° | o - Not worthy of quality commendation |
| H-2: Hardy to -15° | x - Low quality |
| H-3: Hardy to -5° | xx - Medium quality |
| xxx - Good quality | |
| xxxx - Highest quality |
Those not rated were too new or were not grown widely enough to evaluate in 1956 when the ratings were last published.
EDITOR'S NOTE: The designation of bud hardiness as poor, fair or good is on the basis of the average. For example, if nine growers rated a clone "good" and one rated it "fair," the majority evaluation appears. If there was a sizable minority opinion, it is represented, with the majority, in "fair to good."
It is apparent from the replies that growers in Michigan prefer less sun than those elsewhere; one remarked that he would eliminate winter sunlight entirely. It is equally apparent that zone 6 growers elsewhere who are in a climate strongly influenced by the Great Lakes, prefer a good deal more exposure for their rhododendrons, probably because higher atmospheric humidity and a lower general light level makes this possible.
| AZALEAS GROWN | ||||
| Average Bud Hardiness |
Average
(mathematical) % of sun best results |
|||
| Deciduous Hhybrids | Zone 5 | Zone 6 | Zone 5 | Zone 6 |
| 'Aida' (Rustica, rose) | Good | 80% | ||
| 'Balzac' (Exbury, red) | Good | 75% | ||
| 'Basilisk' (Exbury, cream) | Good | 100% | ||
| 'Berryrose' (Exbury, pink) | Good | 75% | ||
| 'Bouquet de Fiore' (Ghent, salmon) | Good | 85 % | ||
| 'Bright Forecast' (Exbury, salmon) | Poor | Good | 75% | 85% |
| 'Cecile' (Exbury, salmon) | Good | 75% | ||
| 'Coccinea Speciosa' (Ghent, orange-red) | Good | Good | 100% | 90% |
| 'Daviesii' (Ghent, white) | Good | Good | 90% | 90% |
| 'Devon' (Exbury seedling group) | Good | 80% | ||
| 'Directeur Moerlands' (Mollis, yellow) | Good | Good | 100% | 90% |
| 'Dr. M. Oosthoek' (Mollis, red) | Good | Good | 100% | 85% |
| 'Essex' (Exbury seedling group) | Good | 80% | ||
| 'Fire Ball' (Exbury, red) | Good | 75% | ||
| 'Freya' (Rustica, salmon, double) | Good | 100% | ||
| 'George Reynolds' (Knap Hill, vellow) | Good | Good | 70% | 75% |
| 'Gibraltar' (Exbury, orange) | Good | 75% | ||
| 'Hampshire' (Exbury seedling group) | Good | 80% | ||
| 'Honeysuckle' (Exbury, pale pink) | Good | 75% | ||
| 'Hotspur Red' (Exbury, red) | Good | 75% | ||
| 'Hugo Hardyzer' (Mollis, red) | Good | 100% | ||
| Ilam hybrids | Good | 75% | ||
| 'J. Jennings' (Exbury, crimson) | Good | 100% | ||
| 'Klondyke' (Exbury, buff-orange) | Good | 65% | ||
| 'Koningen Emma' ('Queen Emma') | ||||
| (Mollis, orange) | Good | Good | 100% | 100% |
| 'Lemonora' (Mollis, yellow) | Good | 100% | ||
|
Mollis hybrids (reported short lived) |
Good | Good | 80% | 85% |
| 'Nancy Buchanan' (Exbury, white) | Good | 75% | ||
| 'Nancy Waterer' (Ghent, yellow) | Good | Good | 85% | 90'/0 |
| 'Narcissiflora' (Ghent, double yellow) | Good | Good | 80% | 90% |
| 'Norma' (Rustica, salmon, double) | Good | 100% | ||
| 'Oxford' (Exbury seedling group) | Good | 80% | ||
| 'Persil' (Knap Hill, white) | Good | 75% | ||
| 'Pucella' (syn: 'Fanny') | ||||
| (Ghent, dark purplish rose) | Good | 85% | ||
| 'Royal Lodge' (Exbury, red) | Good | 75% | ||
| 'Scarlet Pimpernel' (Exbury, red) | Good | 75% | ||
| 'Strawberry Ice' (Exbury, pink) | Good | 75% | ||
| 'Sugared Almond' (Exbury, pale pink) | Good | 75% | ||
| 'Surrey' (Exbury seedling group) | Good | 80% | ||
| 'Sussex' (Exbury seedling group) | Good | 80% | ||
| 'Toucan' (Knap Hill, white) | Good | 75% | ||
| 'York' (Exbury seedling group) | Good | 80% | ||
| Deciduous Azalea | ||||
|
Average
Bud Hardiness |
Average
(mathematical) % of sun best results |
|||
| Species | Zone5 | Zone 6 | Zone 5 | Zone 6 |
| alabamense (white) | Fair | Good | 75% | 80% |
| albrechtii (rose) | Poor to Fair | Good | 65% | 80% |
| amagianum (reported "difficult") (red) | Poor | Fair | 60% | 80% |
| arborescens (white, late) | Good | Good | 100% | 90% |
| atlanticum (white, dwarf) | Fair to Good | Good | 75% | 80% |
| austrinum (yellow) | Fair | Fair to Good | 75% | 85% |
| bakeri (yellow, orange, red, late) | Good | Good | 80% | 70% |
| calendulaceum (yellow, orange, red) | Good | Good | 90% | 85% |
| canadense (lavender, early) | Good | Good | 85% | 85% |
| canescens (pink) | Poor to Fair | Fair to Good | 80% | 85% |
| cumberlandense (yellow, orange, red, late) | Good | Good | 90% | 90% |
| japonicum (yellow, orange, red) | Good | Good | 85% | 90% |
| luteum (yellow) | Good | 80% | ||
| oblongifolium (white) | Fair to Good | 80% | ||
| nudiflorum (pink) | Good | Good | 90% | 85% |
| pentaphyllum (rose-pink) | Poor | 75% | ||
| prunifolium (red, orange) | Poor to Fair | Poor to Good | 80% | 80% |
| quinquefolium (white) | Poor | 65% | ||
| reticulatum (lavender) (reported "difficult") | Poor | Fair | 65% | 80% |
| roseum (pink) | Good | Good | 80% | 80% |
| schlippenbachii (pink) | Good | Good | 75% | 80% |
| serrulatum (white, late) | Fair to Good | 75% | ||
| speciosum (red, orange, yellow) | Poor | Good | 75% | 85% |
| vaseyi (pink, early) | Good | Good | 80% | 90% |
| viscosum (white, late) | Good | Good | 80% | 80% |
| weyrichii (rose-red) (reported "difficult") | Poor | Fair to Good | 65% | 75% |
| Persistent Leaved Azaleas | ||||
|
Average
Bud Hardiness |
Average
(mathematical) % of sun best results |
|||
| Persistent Leaved | Zone 5 | Zone 6 | Zone 5 | Zone 6 |
| 'Amoena' (Kurume, violet-red) | Poor to Fair | 60% | ||
| 'Big Joe' (Gable, reddish violet) | Good | 60% | ||
| 'Billy' (Gable, pink) | Poor | 75% | ||
| 'Boudoir' (Gable, violet-red) | Fair | Good | 75% | 75% |
| 'Campfire' (Gable, red) | Poor | 50% | ||
| 'Carmen' (Kaempferi, pink) | Good | 75% | ||
| 'Cherokee' (Gable, orange-red) | Poor | 50% | ||
| 'Corsage' (Gable, lavender) | Fair to Good | Good | 65% | 75% |
| 'Edna' (Gable, pink) | Poor | 75 % | ||
| 'Elizabeth Gable' (Gable, red) | Poor | Poor | 75% | 75% |
| 'Esther Reiber' (Pride, light lilac) | Good | 75% | ||
| 'Fedora' (Kaempferi, dark pink) | Fair to Good | Good | 75% | 60% |
| 'Geraldine Vuyk' (Vuykiana, red) | Poor | 75% | ||
| 'Grenadier' (Gable, scarlet) | Fair | 60% | ||
| 'Herbert' (Gable, reddish violet) | Poor to Good | Fair to Good | 60% | 60% |
| 'Hexe' (syn: 'Firefly') | ||||
| 'Hino-crimson' (Kurume, red) | Poor | Poor to Fair | 55% | 65% |
| 'Hinodegiri' (Kurume, crimson) | Poor | Poor to Fair | 45% | 60% |
| 'Hinomayo' (Kurume, pale pink) | Good | 60% | ||
| 'James Gable' (Gable, red) | Good | 60% | ||
| 'Joseph Gable' (Pride, white) | Good | Good | 90% | 80% |
| 'Jessie Coover' (Gable, violet-red, double) | Poor | 50% | ||
| 'J. T. Lovett' (syn: 'Macrantha') (orange-red) | Poor | 50% | ||
| kaempferi (species, orange-red) | Fair to Good | 75% | ||
| kaempferi hybrids | Poor to Fair | 65% | ||
| 'La Roche' (Gable, magenta-red) | Poor | 60% | ||
| 'Lilac Time' (Kaempferi, violet-red) | Good | 85% | ||
| 'Louise' (Kaempferi, dark pink) | Good | 80% | ||
| 'Louise Gable' (Gable, salmon) | Poor to Fair | Poor to Good | 50% | 60% |
| 'Lorna' (Gable, pink) | Poor to Good | Good | 65% | 75% |
| 'Kathleen' (Kaempferi, rosy red) | Good | 80% | ||
| 'Marjorie' (Gable-Pride, Pink) | Fair to Good | 90% | ||
| 'Maryann' (Gable, violet-red) | Poor | 60% | ||
| 'Mary Dalton' (Gable, orange-red) | Poor | 50% | ||
| 'Maxwellii' ( pulchrum form, carmine) | Fair | 60% | ||
| 'Mello-Glo' (Dawson, violet-red) | Good | 60% | ||
| 'Mildred Mae' (Gable, reddish violet) | Poor to Good | Good | 50% | 60% |
| 'Mucronata' (syn: 'Ledifolia Alba') (white) | Fair to Good | 75% | ||
| 'Nadine' (Gable-Pride, pink) | Good | 75% | ||
| 'Norma' (Kaempferi, violet-red) | Good | 60% | ||
| 'Old Faithful' (Gable, reddish violet) | Good | 60% | ||
| 'Othello' (Kaempferi, reddish rose) | Fair | Good | 75% | 80% |
| 'Palestrina' (syn: 'Wilhelmina Vuyk') | ||||
| 'Purple Splendor' (Gable, purple) | Fair | 50% | ||
| 'Red Bird' (Glenn Dale, red) | Good | 50% | ||
| 'Rose Greeley' (Gable, white) | Poor to Good | 50% | ||
| 'Rosebud' (Gable, violet-red, double) | Poor to Good | 85% | ||
| 'Royalty' (Gable, reddish violet) | Good | 70% | ||
| 'Sherwoodi' (Kurume, reddish violet) | Good | 60% | ||
| 'Snow' (Kurume, white) | Fair to Good | 60% | ||
| 'Springtime' (Gable, violet-red) | Fair to Good | Poor to Good | 55% | 65% |
| 'Stewartstonian' (Gable, red) | Poor | Poor | 50% | 65% |
| 'Suetsumi' (syn: 'Flame' (Kurume, | ||||
| 'Susan' (Gable, pink) | Fair | 50% | ||
| 'Thais' (Kaempferi, violet-red) | Good | 80% | ||
| Westcroft hybrids | Good | 80% | ||
| yedoense var. poukhanense (Species, lilac) | Good | Good | 90% | 85% |
| 'Yodagawa' (Form or yedoense var. poukhanense ) (Species, reddish violet, double) | Fair to Good | 65% | ||
|
|
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Editor's Note: Parentages and color descriptions in the foregoing lists are taken from The International Rhododendron Register. Many growers recommended shade to some extent for deciduous azaleas primarily to prolong the time the flowers are in good condition, especially for the newer British hybrids. Some shade for persistent leaved azaleas is described as aiding the plants to retain their flower buds in good condition through the winter.
Soil Preparation
Among the growers using the conventional ingredients of topsoil, peat and sand, the mathematical average of proportions for the mix giving the best results:
50% Topsoil 39% Peat 11% Sand
Among the growers using additional ingredients, the mathematical average of proportions for the mix giving the best results:
18% Topsoil 30% Peat 18% Sand 34% Other Humus Sources (Leaf Mold, Compost, Rotted Sawdust, Rotted Manures)
EDITOR'S NOTE: There was provision on the questionnaire to indicate "No special preparation-natural soil without additions." Among all of the replies only two growers indicated that their natural soil produced satisfactory results without modification.
Mulching
The mulches which produce the best results listed in the order of frequency mentioned, with the depth of the mulch stated as a mathematical average of the replies:
Oak Leaves, 4"
Ground Corn Cobs, 1"
Sawdust, 2"
Peanut Shells, 2"
Peat, 2"
Pine Needles, 3"
Serve-All, 1"
Black Polyethylene Plastic
Wood Chips or Shavings, 3"
EDITOR'S NOTE: There was provision on the questionnaire to indicate that no mulch is used. Not one grower indicated that he cultivates rhododendrons or azaleas without a mulch.
Watering
Since municipal water supplies are usually neutral (pH 7.0), the question was asked "Do you use city water or a natural source of water?" The responses:
55% City Water
45% Well, Pond or Stream
Apparently there is no difficulty from loss of soil acidity clue to the use of municipal water, although the surprisingly large percentage of growers who use a natural source of water did not state that this had anything to do with their reason for doing so. All members indicated that they do irrigate their plants. It is usually thought that irrigation of Rhododendrons and Azaleas during the month preceding the first expected frost impairs their hardiness by diluting the carbohydrate concentration in the sap. The question was therefore asked: "Name the latest date in the season prior to frost that you consider it safe to irrigate." The answers, average mathematically:
Zone 5: August 14th
Zone 6: September 6th
Fertilizing
The fertilizers which produce the best results, listed in the order of the frequency mentioned:
Ammonium sulphate
Cow manure
Cottonseed meal
Agrico for Broadleaf Evergreens
Westcroft's Greenleaf Compound
Kapco Evergreen 7-7-7
Sheep manure
8-6-6
Eastern States Starter
G. & O. Azalea Fertilizer
Ammonium Sulphate plus 0-25-25
Cottonseed meal plus 0-15-15
5-10-5
30-10-10
8-8-8 (organic)
16-8-8
6-8-0
Ureaform
It is usually thought that fertilizing Rhododendrons and Azaleas within 60 clays of the first expected frost impairs hardiness by stimulating unseasonably late growth. The question was therefore asked, "Name the latest date in the season prior to frost that you consider it safe to fertilize." The answers, averaged mathematically:
Zone 5: July 15th
Zone 6: June 18th
EDITOR'S NOTE: There was provision on the questionnaire to show that the grower did not use any fertilizer. Only one did not. It is interesting to note that growers in zone 6, where the first frosts are a good deal later than in zone 5, are much more conservative in extending the season of fertilizer use. Many of our members in zone 6 are professional growers.
Spraying and Dusting
The insecticides which produce the best results, listed in the order of frequency mentioned:
Malathion
DDT
Dieldrin
Lindane
Aldrin
Aramite (miticide)
Nicotine and soap
Methoxychlor
Tedion
Vapotone XXX
DX
The fungicides which produce the best results, listed in the order of frequency mentioned:
Captan
Fermate
Sulphur
Parzate
Karathane
Fixed Copper
EDITOR'S NOTE: Malathion as an insecticide and Captan as a fungicide has no serious competition in the preference of growers. 23% of the growers stated that they do no spraying or dusting whatever.
I recommend that the portion of the survey relating to the bud hardiness of rhododendrons and azaleas, both hybrids and species, be repeated in 1963. Many growers commented that they had not grown some of the newer hybrids and rarer species long enough to have a valid opinion of their bud hardiness, and declined to rate them until they had more experience with them.
