QBARS - v17n4 Effects of the Severe Winter

Effects of the Severe Winter
Ted Hinson, Charlotte, N.C.

We became interested in Rhododendrons because we had some old Catawba hybrids that were planted 35 years ago and continue to thrive, at 9 feet tall, today-with no attention.
We started with other hybrids three years ago. As a quick preliminary resume, I might say we have had little success with dwarf or yellow varieties. In the dwarfs we have lost all (6 to 8 plants each) of 'Hummingbird', 'Golden Horn', 'Blue Diamond', 'Wilbar', 'Sapphire', 'Vanguard', and 'Cilpinense', 'Jock' and 'Cutie' are doing well. Plants of 'Elizabeth' are gradually dying, though planted both in sun and in shade. We are still experimenting with other dwarfs.
In the "yellows," we have lost all of 'Mrs. Betty Robertson', 'Unique', 'Butterfly' (two attempts), 'Hawk Beaulieu' and 'Hawk Jervis Bay'. We are still experimenting with other "yellows," and other large varieties.
Of the tall varieties most have done well, or have recovered nicely from the very severe winter of 1962-1963. A history of the plants we have had for two years or longer, except those mentioned above, may be of interest.
Last winter was the most severe we have had in many years, with the temperature below freezing for weeks at a time, and with a minimum of 2 degrees F. A brief climatological summary is given. Incidentally our rainfall to date this year shows a deficiency for 1963 of about 7½ inches but the temperatures have been below normal, which helps.
We have many different species, but most of these plants are too young to report on. We have planted over 40 other varieties this year on which we can report later. Of course, the performance reported herewith is only preliminary. Time and the experience of others will really tell. Too often, down here, a variety is condemned because of a single report. However, we do believe that our experiences may serve as valuable guideposts, since there are few reports from this area.

Climatological Summary, Charlotte, N.C.
1962 1963
Month of: Sept. Oct. Nov. Dec. Jan. Feb.
Avg. monthly temp., °F 71.2 62.6 48.0 38.0 37.3 37.5
Departure from norm., °F -1.2 +0.6 -2.9 -5.2 -6.1 -7.2
Highest, °F 94 87 68 67 69 64
Lowest, °F 44 24 27 2 7 7
Total Precip. for Mo., 5.06 1.57 5.33 3.01 2.71 3.15
Number of days with
minimum of 32° F or lower
- 3 7 22 22 24
Number of days with
maximum of 32° F or lower.
- - - 3 1 -
Source U.S. Dept. of Commerce, Weather Bureau

The spring and summer of 1962 were unusually dry and windy. During September, due to an excess rainfall of about 50%, most plants tried to recover from the unfavorable growing season. In early October, the rhododendrons were a "picture of perfect health," with heavy flower bud set.
Without any previous frost of significance, on Oct. 26 the temperature dropped to 29° F. This was followed by a very hard freeze on the 27th with a 24° F. low. These days were bright, cold and windy.
By mid-November, it was readily apparent that the October freeze had done considerable damage. Although the table above indicates that the December temperatures would probably have caused some damage, we feel that the October freeze was the largest factor.

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Percentage Estimate Of Damage To:
Bud Leaf Stem Comments
'A. Bedford' H3 0 0 0 Bloomed well this year.
'Anna Kruschke' 0 0 0 Small plants.
'Alice' H3 0 0 0 Has been disappointing.
No blooms in two years.
'America' H1 0 0 0

Most satisfactory.
Good growth, heavy bloomer.
'Antoon van Welie' H3 0 0 0 Thrives in sun or shade.
'Azma' H4 50% 50% 0 Recovering very well.
'Beauty of

H3 0 0 0 No blooms in three seasons.
Good growth each year.
'Betty Wormald' H3 100% 0 0 Moved from full sun-doing.
much better in shade.

'Blue Ensign' 0 0 0 Very satisfactory growth and blooms well.
'Blue Peter' H2 15% 0 0 Has done well in full sun and in
'Corry Koster' H3 100% 0 0 Afraid plants will die eventually.
'Countess of Athlone' H3 100% 0 0 Good growth each season.
'Cutie' H2 100% 0 0 Plants very young.
'Cynthia' H3 50% 0 0 Doing very well.
'Damozel' H3 75% 0 0 Best all-around growth of all plants.
'Day Dream' H4 100% 50% 0 Very satisfactory growth
'Dexter hybrids'
H3 0 0 0 Good growth and good blooms.
'Doncaster' H3 0 0 0 Very satisfactory.
'Dr. A. Blok' H3 100% 0 0 Excellent color now.
Planted too high at first.
'Elizabeth' H4 100% 100% 80% Both sun and shade plants
'Fastuosum Flore Pleno' H2 100% 0 10% Disappointing growth in shade.

Percentage Estimate Of Damage To:
Bud Leaf Stem Comments
'Garnet' H4 100% 50% 40% All plants recovering nicely.
Full Western sun.
H3 95% 30% 20% Has not done well in three seasons in sun or shade.
'Jan Dekens' H3 0 0 0 Plants young, but growth good.
'Jean Marie de
15% 0 0 Doing well in full Western sun.
'Jock' H3 95% 0 0 Recovery good.
'Kiev' H4 100% 100% 95 % Slow recovery from roots.
'Lady Bligh' H3 100% 0 0 Didn't do well in sun. Doing excellently in shade.
'Lady Clementine
H3 100% 0 0 Moved to sun from shade and doing much better.
'Lady Stuart of
H4 100% 0 0 Moved from sun to shade and doing much better.
'Loder's White' H4 0 0 0 Plants very young but promising.
'Mme. de Bruin' H3 100% 50% 25% Since moved from shade to sun 100% recovery.
'Margaret Dunn'
var. 'Golden Bell'
H3 100% 100% 15% Having hard time recovering.
'May Day' H4 100% 75% 45% Lost two plants. Recovery slow.
'Medusa' H4 100% 50% 15% Recovery slow.
'Mother of Pearl' H4 100% 0 0 Recovery good.
'Mrs. Chas.
E. Pearson'
H3 100% 0 0 Plant growth good.
'Mrs. E. C. Stirling' H3 65% 0 0 Satisfactory plant.
'Mrs. J. C. Williams' H3 100% 0 0 Moved to sun-doing much better.
'Mrs. Mary Ashley' H3 100% 95% 60% Moved from sun to shade.
Recovery good now.
'Mrs. T. H. Lowinsky' H3 10% 0 0 Needs less attention than all others.
'Penjerrick' H4 100% 100% 100% No recovery.
'Pink Pearl' H3 80% 0 0 Did poorly in sun. Doing well in shade now.
'F. C. Puddle' H4 100% 75% 30% Lost two plants.
Recovery in others good.
'Purple Splendour' H2 0 0 0 Plants young but doing well.
'Radium' H4 100% 40% 25% Moved from shade - doing much better in part sun.
'Roseum Elegans' Hl 75% 0 0 Growth disappointing so far.
'Sappho' H3 100% 0 0 Growth good in sun and shade.
'Scandinavia' H4 50% 0 0 Doing O.K.
'Van Nes Sensation' H4 100% 0 0 Very satisfactory plant in every way.
'Vulcan' H3 10% 0 0 Full Western sun-progress slow.
'White Pearl' H4 l00% 0 0 Making progress this summer.
'White Swan' H4 100% 50% 30% Since moved from sun to shade recovery excellent.