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.

Percentage Estimate Of Damage To:
ARS
Rating
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