QBARS - v34n2 What About Evergreen Azalea Hardiness

What About Evergreen Azalea Hardiness
Capt. R. M. Steele, Rose Bay, Nova Scotia
Reprinted from Rhododendron Society of Canada Bulletin

Here by the sea there are a few of us who are always seeking interesting, hardy and beautiful plants. We do so aggressively and shamelessly but often with a great deal of pride.
You must pardon our play on words - but - the Pride we refer to is Orlando S. Pride of Butler, Pennsylvania; a quiet, reserved, almost shy gentleman of very substantial importance to rhododendron enthusiasts in Canada, both for the present and in the future.
The reason Lanny Pride is important to us is that for more than fifty years he has been growing and breeding rhododendrons, azaleas and hollies in an area of North America where winter temperatures are often very cold. He started growing these plants, although at that time all the advice was that they could not survive in that climate.
Lanny not only produced plants of rhododendrons, azaleas and hollies that have survived but in doing so he has established genetic hardiness qualities which will be of great benefit to those in the future who may wish to breed these plants for cold Canadian areas.
Orlando Pride is one of the important Plantsmen of our time. His tenacity over a very long period was not limited to hardiness alone. He is an objective and skilled judge of beauty in plants and many of his creations have been major award winners.
In Nova Scotia we have so far had very limited results from our attempts to find evergreen azaleas which will perform satisfactorily here. Our recent breeding with the Japanese species R. nakaharai and also R. kiusianum have produced plants that are encouraging.
Before embarking on more extensive breeding for hardy azaleas, we asked Lanny about his azaleas and his experience and observations. Here is what Lanny says:
Letter from Lanny
November 19, 1978
"I have been intending to write a fifty-year report on azaleas that I have tried in Butler, and what has survived and flowered with distinction. When I got out of Penn State in 1928 and started in the landscape business there were practically no evergreen azaleas on the market that had a ghost of a chance to live and bloom in Butler. I bought one hundred plants of Azalea kaempferi from Henry Kohankie Nursery in Painesville, Ohio, for Mrs. Beendum of Pittsburgh, Pa. She turned the entire order down because they looked so sick and I was stuck with them. I planted them out in my nursery and they slowly died out. I don't think I ever saw a flower on any of them. About 1933, Charles Robinson, a Landscape Architect and a fraternity brother of mine, told me about a man named Joseph Gable of Stewartstown, Pa. who had a quantity of large sized azaleas. Chuck was the landscape architect for the Fort Necessity Park near Uniontown, Pa.
Chuck had me order about one hundred and fifty of these azaleas for the park. Well, my brother Arthur and I went down to Gable's and bought our first load of these beautiful plants. They were un-named ones and about 2½-3'tall - big full plants. Shortly after Art and I went back down to Gable's and bought another hundred plants and brought them to Butler. Fifty of these azaleas were sold to Dr. Norbert S. Garbisch and were planted in his three-acre garden. Some were planted on the J. S. Campbell estate. We retained about twenty-five for our own experimental work. A few years later a friend of Mr. Garbisch, T. J. Ingram of Pittsburgh, ordered one hundred of Gable's azaleas, which we planted on his estate on Woodland Road in Pittsburgh. During all these visits to Gable's we would buy small azaleas of the named varieties which were available from time to time. Many of these were simply by numbers. We soon learned that all the small-sized named azaleas split bark and promptly died during our severe winters, but the large unnamed azaleas survived and bloomed quite well. It was some time later when we went back to Gable's for more azaleas that he told us the Dauber Nursery at York, Pa. had larger plants of a good many of his named azaleas. We then purchased a few hundred of the named Gable azaleas from Dauber's Nursery and found that they survived and bloomed to some extent when the winters were not too severe.
About ten years after we had planted the first hundred un-named azaleas from Joseph Gable, we found that three of these had bloomed very well in the Garbisch Garden for the past ten years without a miss. I named a beautiful peach pink for their daughter, Nadine; a very bright orchid pink for another daughter, Marjorie; a very beautiful coral for their daughter, Vicky. This is perhaps the most beautiful plant of the group but not quite as bud-hardy. Another, a vivid kaempferi red was named for Mrs. Garbish, and one, which I called 'Norbert' was named for Mr. Garbisch. It also is a very vivid kaempferi red.
The three which bloomed every year for the ten years were 'Nadine', 'Marjorie' and one I called 'Pale Lilac'. Now 'Nadine' never went over very well due to the fact that it does not root readily, nor is it very vigorous when small. It takes five years or more to produce a 15" plant. ' Marjorie' is very vigorous and has been grown by a very successful nurseryman. It still does not compete with the more tender azaleas in making a saleable plant in a hurry. 'Pale Lilac' is simply a large flowered azalea about the color of 'Corsage'. 'Pale Lilac' roots like privet and is perhaps the most hardy azalea we ever grew in this area. It grows like a weed and if it were a good red, would be worth a fortune. Donald Zaum of Wasco, Illinois, fifty miles west of Chicago, has had 'Pale Lilac' and 'Marjorie' for a number of years. He reported that 'Pale Lilac' was the only azalea to bloom for him after the winter of 1977 when he had minus 28° F.
Anyway, to finish up the story about 'Nadine', 'Marjorie' and 'Pale Lilac', they have now bloomed every year in the Garbisch Garden in Butler for the past thirty years. At my nursery 5 miles south of Butler they have missed a few of the thirty years, yet the plants are in perfect health.
Shortly after I found that `Nadine', 'Marjorie' and 'Pale Lilac' were so bud hardy I started growing thousands of seedlings each year. Also started was the crossing of many of them with 'Nadine', 'Marjorie', and 'Pale Lilac'. I had a very small greenhouse out at my nursery located in a low area below a spring, which kept it well watered without much help. I would plant this entire house with seeds of 'Nadine', 'Marjorie' and 'Pale Lilac', and have a crop of as many as 50,000 per year. I had seedlings coming out of my ears.
One year I crossed 'Nadine' with Gable's 'Rose Greely'. 'Rose Greely' split bark every year and I had trouble keeping it alive. Anyhow, I finally got a small amount of seed from this cross and they came up beautifully, about 35 plants. Well, a flash flood came down my little valley and covered every seedling in my greenhouse with mud. I thought I had lost everything, but I took a sprinkling can and started washing off the mud and to my surprise, I save quite a few. The little group of 'Nadine' x 'Rose Greely' had all passed out except for one husky plant. I prized the little fellow and guess what - it grew up to be the hardiest white I ever had. I named it 'Joseph Gable'. I was reluctant at first to name it for such a great person, and certainly didn't want to name a poor azalea for him. Anyhow, Caroline Gable has it and thinks highly of it. It has taken a number of years to prove itself. It is without a doubt the most bud-hardy white I have ever tested here in Butler. The flowers are the size of 'Rose Greely', but the plant is a good strong grower and has never been injured in any way in 20 years or more. Heasley Nursery is growing it commercially with good success.
In the winter of 1949, I had a field of 'Nadine', 'Marjorie' and 'Pale Lilac' seedlings - about 20,000 of them. That winter the temperature dropped to 20 below F. or more and the following spring I selected about fifty and named them. I called them the 49-ers.' These all did very well for me until the winter and spring of 1963 when some of these plants were injured, when a late spring freeze killed even small white oaks. However, the following azaleas of the 49-ers have survived without any plant injury and have flowered with great display over many years. They are 'Charles A. Pride', 'Betty Pride', 'Dr. Kottraba', 'Mrs. Cribbs', 'Mrs. John Wilson', ' Ling Close" and 'Red Satin'. There are perhaps another ten or so that should be named.
Late spring frosts were the bug-a-boo to many of our azaleas; just as they would come into bloom we would have a heavy frost and very often a deep freeze, and away would go all our pretty flowers. I thought that it was about time that I looked for the later blooming azaleas, so about 25 years ago I started on the search of the later ones. 'Pride's Pink' is perhaps the latest to bloom for me but I have not had it long enough to have a good test for the buds. 'Pride's White' is very plant hardy and also bud-hardy. 'Pride's Pride' is also late and has bloomed very well after late killing frosts.
In my opinion, it takes at least 15 years to really test a plant. After that time has passed, you begin to feel the plant may be worthy of being planted in greater numbers.
The following named azaleas have been grown in our nursery, but most of these only bloom with any degree of success every ten years. 'Springtime' was recommended to me by Mr. Gable as being very bud-hardy, but I am sorry to report that it has only bloomed once in every five or six years. The following Gable azaleas have survived our winters fairly well as plants, but only have a good show of flowers about every ten years: 'Stewartstonian', 'Herbert', 'Purple Splendor', 'Caroline', 'LaRoche', 'Corsage', 'Mildred Mae', 'James Gable', 'Chinook', 'Mary Frances Hawkins', 'Boudoir', 'Billy', 'Louise Gable', 'Elizabeth Gable', 'Rose Bud', 'Lorna', 'Indian Summer', 'Springtime', 'Carol', 'Campfire', 'Jimmie Cover', 'Palestrina', and 'Margie'.
About 15 years ago I crossed R-4-G, which is now named 'Margie', with some of the most bud-hardy hybrids of 'Nadine'. Many of these hybrids have been quite bud-hardy and show promise for testing elsewhere. 'Susan Page' is one that is a coral pink hose-in-hose and does very well for me. Another which is very late is 'Pride's Pride'. It has had a very good record.
The great hurdle to overcome in growing the Obtusum azaleas in a severe climate like ours, is getting the young plants to survive the first few winters. I have had very little trouble rooting all the semi-evergreen azaleas, then carrying them over in a greenhouse until the following spring. They are then planted out in beds after danger of late frosts and then mulched with pine boughs the first winter they are out. Then if we get a severe early freeze, nearly all these young azaleas will split bark and die. I wish I had a nickel for every semi-evergreen azalea that I lost due to the splitting of the bark at the soil line. The bark splitting is so bad on some varieties that it will occur to plants that are three years old. That is the reason I never had any plants of 'Caroline' to sell. The azaleas which I named for Mr. and Mrs. Garbisch, namely 'Victoria' and 'Norbert', split bark even after three years in the field.
Over the period of years, I came up with a group of our hybrids that did not split bark, survived the first few winters and grew on into landscape-sized plants. I was always careful not to fertilize any of these azaleas. If we had late rains and the plants kept on growing in the fall, and there was an early heavy frost in early fall, I could expect to lose a good many. However, I did come up with a group of what I called no-splits. 'Marjorie' and 'Pale Lilac' are perhaps the most foolproof and produce the most saleable plants for me in the shortest period of time. I crossed a hardy hose-in-hose, 'Linwood White' with Joseph Kallay's 'Snowball' and the result was our 'Pride White'. It is a single white, but is the most evergreen of all my hybrids and very bud-hardy. Out of all the many thousand hybrid seedlings which I grew, I think the most bud-hardy reds are 'Winnie Greer' and 'Sam Greer'. These are selected out of a field of thousands as the most bud-hardy. They are not very vigorous when young but do grow into fine plants in time. The other red is 'cordon Greer'. It is more vigorous and should be worth trying.
I have just looked over the list of azaleas that I rooted and planted out the past spring. Some of these may be worth another look; that is why I rooted them and hope to grow them on. They are 'Thor', perhaps a little more bud hardy than 'Marjorie'; 'Shell', an old timer that Dave thought very hardy; 'Red Poukhanense', 'Pride's Old Faithful', 'Pride Super Hino-Red', 'Everbloom', 'Jack Jamison', 'Sue Paterno', 'Nudiflora Pink', 'Edith'.
To sum up the search for the perfectly bud-hardy semi-evergreen azalea for climates like mine, I think the only approach is to fine two very hardy parents, cross them and grow a very large population of seedlings. Even when you cross two very hardy parents, the offspring do not necessarily give you a very high percentage of bud-hardy plants. Many times it appeared to me that the offspring were not as bud-hardy as the parents. It is very much like trying to find the needle in the haystack, and worse yet, it takes 15 years or more.
I have developed some very hardy deciduous azaleas which seem to be more bud-hardy than many of the Exbury and Ilams. I'll try and give you a report on them later. I hope to be able to write up my first fifty years with rhododendrons. That will take a little more time.

Editor's Note:
In the summer 1980 issue we will be publishing Lanny's 50 year report on rhododendrons in Western Pennsylvania replete with lots of outstanding color pictures.