My ‘Minuta’ Mea Culpa

While North American horticulturists have been selecting and growing dwarf conifers since the mid-1800s, they did not become widely available to the gardening public until the 1960s when specialty nurseries began expanding their offerings to meet an increasing demand for unusual plants. The writings of serious collectors such as William Gotelli of New Jersey and Helen Bergman of Pennsylvania played an important part in introducing people to dwarf conifers. The eastern hemlock (Tsuga canadensis) was a major player in this emerging field because of its propensity to generate mutant forms.

My interest in hemlock cultivars began in 1979 when I met Gus Kelley of Little Compton, Rhode Island, shortly after I started working at the Arnold Arboretum. Gus was a dwarf conifer enthusiast who had started his own horticultural publishing house, Theophrastus, in the early 1970s. He published my book about Sargent’s Weeping Hemlock—A Giant Among the Dwarfs—in 1983, and a year later, my second hemlock book, St. Georgie and the Pygmies: The Story of Tsuga canadensis ‘Minuta’. In both cases, I tried to sort out the contradictions in the literature regarding the origins of these plants, but the process turned out to be much more complicated and time consuming than I ever imagined. Indeed, it took me forty-two years and three tries to finally nail down the history of Sargent’s weeping hemlock, and the article you’re reading now is a revision of my thirty-nine year old book about the ‘Minuta’ hemlock.

The Dwarfest of the Dwarfs

The cultivar ‘Minuta’ is a true genetic dwarf consisting of several morphologically indistinguishable clones. It is a slow and steady grower—never more than an inch a year and often half as much—and shows no tendency to “revert to type” the way many dwarf conifers do. Its congested foliage lacks measurable internodes and, over time, forms a dense dome of foliage that’s a perfect fit for any rock garden. The oldest specimen of the ‘Minuta’ hemlock that I am aware of is at the Arnold Arboretum. It was one inch tall in 1970 and was 39 inches high by 50 inches wide in 2022—for an average height increase of 0.65 inches and a width increase of 0.94 inches per year.

‘Minuta’ was introduced to the horticultural world in 1935 by Henry Teuscher of the New York Botanical Garden, who published a description of the plant based on information and a photo provided by George L. Ehrle, a nurseryman from Clifton, New Jersey. In his article, Teuscher reported that the plant had been discovered in Vermont in 1927 by an unknown person who not only collected some twenty-five dwarf seedlings over an eight-year period but also discovered their purported parent that was two feet tall and producing cones. Teuscher used the Latinform botanical name, var. minuta, to describe the plant because “this variety breeds true from seeds.”

The complete story of ‘Minuta’s’ origin—including the name of its discoverer—did not emerge until four years later in John Swartley’s Cornell University Master’s thesis, Canada Hemlock and Its Variations from 1939. His full entry for T. canadensis var. minuta reads as follows:

This plant which is probably 25–35 years old, was collected near Charlotte, Chittenden County, Vermont, and is now growing in the rock garden of George L. Ehrle, Clifton, New Jersey. The following story has been gleaned from correspondence between Mr. Ehrle and Daniel M. St. George of Charlotte, Vermont, the finder of this interesting strain of Canada hemlock.

Several years ago, a Mr. Craig informed Mr. Ehrle of the existence of this very dwarf strain and Mr. Ehrle at once investigated the possibility of acquiring a specimen. He was informed that there were two plants available at five dollars each so he quickly ordered these and they were received September 10, 1934. Mr. St. George reported that they had been dug in 1927 on the north slope of the Green Mountains, at a rather high altitude in a small open area with normal hemlock growing on all sides. Mr. St. George dug some small plants in 1931. In 1934, he again visited the site and collected another lot of plants and found the parent which was about two feet high and very dense, just like the small ones. It was standing beside a maple tree, crowded one side by a spruce, but it was bearing cones and seedlings were distributed within 150 feet. This plant must have been more than 50 years old. In the spring of 1935, another visit was made but the place had been so closely grazed by cattle that not a single plant like the other could be found and even the parent was dead. However, Mr. St. George reported digging two faster-growing plants 4 feet high and observing several more with similar foliage.

Mr. St. George transplanted all of these dwarf hemlocks to his small nursery, shading them only the first year. He stated that they were easy to establish and very hardy. Altogether, he dug and sold 25 to 30 plants, but with the exception of Mr. Ehrle, he has no record of the identity of his customers.

Mr. Ehrle used one of the small plants to supply scions for grafting, but without success. The other plant is not thriving, but some cuttings have been successfully rooted by Mr. Ehrle, therefore this strain will not be lost. This plant was used by Teuscher in describing var. minuta, therefore it is unquestionably the type plant of that variety.

Unfortunately, Swartley’s thesis was never published, so St. George’s role as the discoverer of ‘Minuta’ was not widely recognized until 1965 when two Dutch authors, P. Den Ouden and B. K. Boom, excerpted it for their entry on Tsuga canadensis in their Manual of Cultivated Conifers. During this twenty-six-year gap, the history of ‘Minuta’ became hopelessly entangled with the very similar cultivar, ‘Abbott’s Pigmy’. The main sources of this confusion was none other than Charles F. Jenkins, the founder of the Hemlock Arboretum in Germantown, Pennsylvania, and the author of the Hemlock Arboretum Bulletin at “Far Country”, published quarterly between 1932 and 1951. In the October 1933 issue, Jenkins talked about visiting Frank Abbott, a noted plant collector, at his summer home in Athens, Vermont. Among the various mutant hemlocks growing in the nursery, Jenkins described “a dwarf pincushion which he had gathered on the hills on the south bank of the Winooski River, in Richmond.” In his 1939 thesis, Swartley described the same plant as “very similar” to Teuscher’s T. canadensis var. minuta, but with leaves arranged more horizontally than radially. He also reported that Abbott had collected his plant north of Richmond “on the west side of the Winooski River, on the same ridge of mountain as Teuscher’s [plant], and only about 10 miles away.”¹

For whatever reason, Jenkins and Teuscher seemed intent on erasing Daniel St. George from the history of ‘Minuta’.

In the April 1948 issue of the Bulletin, Jenkins announced that the plant he had described as a “dwarf pincushion” in 1933 should now be called “Abbott’s Pigmy Hemlock.” Unfortunately, the photo that went with the article was not of Abbott’s plant but of the plant St. George had sent Ehrle fourteen years earlier in its distinctive strawberry box. In the next issue of the Bulletin, Jenkins published a long article in which he owned up to his mistake with the photo but then omitted a crucial part of the plant’s history by failing to mention St. George. This was a particularly glaring omission given that he specifically thanked Swartley for his help in preparing “this explanation and correction.”

A year later, Henry Teuscher burst through the door that Jenkins left open with his own article about “Abbott’s Pigmy Hemlock” that asserted that Frank Abbott was the one who actually discovered the botanical oddity in Vermont in 1927 and sold plants to George Ehrle in 1934. For whatever reason, Jenkins and Teuscher seemed intent on erasing Daniel St. George from the history of ‘Minuta’. Why they chose to do this will never be known, but it could well have been to protect Abbott’s reputation—either because he didn’t want to admit that he purchased his pygmy hemlock from St. George or poached it from his secret collecting location.

The confusion surrounding ‘Minuta’ was exacerbated by the emergence of a second lookalike hemlock called ‘Pygmaea’ in the 1940s. The history of the plant was described by Joel Spingarn who had propagated a specimen “from a single cutting generously given to him by Mr. William Gotelli” in 1959. According to Spingarn, Gotelli got his ‘Pygmaea’ from Henry Hohman, who got a plant from Joseph Gable in 1941, at which point the trail went cold. Based on the two plants growing in his garden, Spingarn asserted that ‘Pygmaea’ could be distinguished from ‘Minuta’ by virtue of the fact that it grew much more slowly.

My own research at the Arnold Arboretum on the growth rate and needle length on three plants of ‘Minuta’ and two of ‘Pygmaea’ (including one from Spingarn) showed that the differences between them were insignificant and better explained by phenotypic responses to environmental conditions than by genetic variation. I went on to postulate that ‘Pygmaea’ was probably just a synonym for ‘Abbott’s Pigmy’ and recommended that all three plants—which were hopelessly confused in the nursery trade—be lumped under the cultivar name ‘Minuta’.²

A Visit with Daniel St. George

This is where things stood in 1984, when I published St. George and the Pygmies. In the book, I reported visiting the 91-year-old Dan St. George at his home in Charlotte, Vermont on April 11, 1981. I had decided to go there because, amazingly, none of the parties who had written about ‘Minuta’ had actually talked with him about his discovery and I wanted to get the story directly from him. Shortly after my arrival, Dan took me outside to show me three “dwarf” hemlocks growing in his yard that he had collected—one was a dense pyramid about ten feet tall and the other two were narrow and sparsely branched and about eight feet tall. I was disappointed that none of them looked like ‘Minuta’, so I showed him the picture of George Ehrle’s strawberry box specimen from Teuscher’s 1935 article and asked him if he had ever collected something like this. He looked the image over carefully and said he never found anything that looked like that plant. I pressed him further, but he stuck to his story, stating that he and his partner, Larry Root, discovered a number of dwarf hemlocks in Richmond, Vermont on the east side of the Winooski River, just beyond where Route 2 crossed over an old iron bridge, in a wet area behind the so-called “checkered house.”³ They collected thirteen hemlock in 1928, including the two narrow, sparsely branched plants in his yard. In 1932, he returned to the site and dug a fourteenth plant that grew into his dense pyramid.

The only person who St. George told about the Winooski River site was his good friend, Fred Abbey of North Ferrisburg, Vermont, who, like St. George, was a breeder and grower of lilies. While St. George denied knowing George Ehrle, he did say that he knew William Craig, of Weymouth, Massachusetts, the man whom Swartley credits with telling Ehrle about St. George’s dwarf hemlocks. Craig, it turns out, was a lily expert and a friend of both St. George and Fred Abbey. So lilies seem to be the glue that holds the ‘Minuta’ story together—St. George told Fred Abbey about his hemlocks who told William N. Craig, who told George Ehrle, who told Harry Teuscher.

While I didn’t realize it at the time, the collecting location that St. George told me about was just across the river from where both Jenkins and Swartley said that Frank Abbott had collected his pigmy hemlock—a coincidence that suggests Abbott might have heard about the site from one of St. George’s horticultural buddies. Regardless of whether it was on the east or the west side of the river, it’s a flat area that in no way can be considered the “north slope of the Green Mountains, at a rather high altitude” where St. George told Ehrle he had collected his ‘Minuta’ seedlings.

A couple of weeks after my visit, I sent St. George a questionnaire about his hemlock collecting activities just to make sure I had gotten the story straight. The survey included two specific questions about George Ehrle and he returned it to me with the clear answer that he did not know him. He also denied collecting anything that looked like ‘Minuta’. In an attempt to make sense of his denial in my book, I speculated that, “St. George’s memory could have become clouded during the more than 50 years that elapsed between the actual discovery of the plants and my interview with him.” I didn’t really believe this, so I proposed instead that Swartley’s version of the story was based on conversations with George Ehrle rather than letters from St. George. How wrong I was.

Mea Culpa

When my book came out in 1984, it was pretty much ignored by everyone who wasn’t a fanatic dwarf conifer collector. Later that same year, John Swartley published an updated version of his 1939 thesis under the title, The Cultivated Hemlocks, with revisions by Humphrey J. Welch. In his book, Swartley stuck to the ‘Minuta’ story described it in his thesis, which pretty much wiped out any traction that my version of the story might have generated.

Such was the state of affairs until February 17, 2006—twenty-two years later—when, out of the blue, I received an email from Paul B. Plante II who had purchased St. George’s house and all its contents in 1984, a year after his great uncle Dan had died. In his email, Paul told me that he had seen my book and had another piece of the puzzle for me to ponder, “On page 20 of the book, you state that Uncle Dan denied knowing George Ehrle or ever having corresponded with him. As you posit on page 21, it does indeed seem that Uncle Dan had a lapse of memory… I found no less than 13 letters from Mr. Ehrle on his letterhead, and 2 penny postcards. Below is a link to a high res scan of a letter thanking Uncle Dan for the ‘dwarf hemlock’ on Oct 6/34.” As far as I can tell, I never answered Paul’s email, but I did download the scan of letter he attached.

The matter rested here—unresolved—until December 2022, when I started work on a project about another of my favorite hemlock cultivars, ‘Cole’s Prostrate’. In going through various hemlock images on my laptop, I came across the letter from Ehrle to St. George, but I had no idea where it came from. I typed “St. George” into the search box on my email account and at the bottom of the results list was the 2006 message from Paul Plante with the attached copy of the Ehrle’s letter. With Google’s help, I got in touch with Plante, who took no offence at the fact that I was answering his email sixteen years late. He would be more than happy to send copies of the letters to George Ehrle, provided he could remember where he had put them. To my amazement, I got an email from him two days later letting me know that he had found the letters and would send me scans.

Letters clearly prove that Daniel St. George discovered Tsuga canadensis‘Minuta’.

Below are excerpts from eleven of the fifteen letters from Ehrle to St. George that relate to the discovery and distribution of ‘Minuta’. The first one is dated August 17, 1934 and the last one, November 13, 1935—a span of nearly fifteen months:

Aug 17, 1934: “Mr. Wm. N. Craig of Weymouth was at our Nursery today and told me had seen at your nursery a dwarf form of hemlock … Would be glad to get a plant of your dwarf variety. What is your price for these.”

August 24, 1934: “Enclosed find $5.00 for which send me one of your dwarf hemlocks so I can see what this plant looks like.”

September 19, 1934: “Your dwarf hemlock arrive in good condition.”

September 27, 1934: “Thank you for the information on the dwarf hemlock and enclosed find a check for $5.00 for your other plant … I should like to have a picture of the parent plant. How old do you think it is. Would it be possible to get a few grafts of the old plant in the winter. Let me know when you go to get some of the other small ones. As I should like to buy one the size of a thimble.”

October 6, 1934: “I received the dwarf hemlock in good condition on Thursday … You mentioned the only time you could find these was in spring. When you go I wish you would collect a small branch with a cone on it. What would you ask for the old plant. It may be found or destroyed by some one.”

October 17, 1934: “About a week ago I wrote in regards to the small hemlock. You see this plant can’t be propagated either from cuttings or grafts. As they are to small therefore I am so anxious in getting a few more plants … When you go to get the other small plants next spring let me know and if your price is not to high I will take all you can spare.”

November 7, 1934: “Would gladly pay you $25.00 for the old plant if you ever care to sell it.”

December 13, 1934: “If you could transplant the old plant and grow it in the nursery for one year, I would give you $75.00 for it. The first one I got from you is more compact than the last one. It is the last one I like best because of its irregular growth. I take it from your letter that both of these are from the 1927 collected trees.”

“Let me know when you go to get some of the other small ones. As I should like to buy one the size of a thimble.”

February 28, 1935: “Why I am anxious to get this plant is for my collection because it is the original plant. I would be willing to give you all the seed it produces every year. If you would not care to sell it, perhaps some time you could let me have a few grafts.”

March 2, 1935: “I note what you said about the hemlock. If it is growing among the roots of other trees be careful and don’t take any chances. If that should be the case it would be better to root prune the plant for one year. Another question how close does this dwarf grow to other hemlock. It seems that the seeds self pollinate it otherwise there would be a greater variation among the plants.”

November 13, 1935: “Should you go in the neighborhood where you got the small hemlock from I hope you may be able to fined a few plants. Its to bad I did not learn sooner that you had these. I would have bought every one from you and the old plant too. I would of made a special trip to get it. Should you not be able to fined any would be kind enough to see if any seed pods are on the old plant, these are not good. I wanted to see the size of them and also get a part of the trunk only a small section say 6 inches or it.”

These letters clearly prove that Daniel St. George discovered Tsuga canadensis ‘Minuta’ and that Swartley’s thesis description of the plant’s origin was based on the letters St. George sent to Ehrle. Another thing that stands out in the correspondence is Ehrle’s intense interest in the old cone-producing plant and his repeated, but futile, efforts to get St. George to sell it to him. According to Swartley, St. George discovered the supposed parent in the spring of 1934, but a year later, “the place had been so closely grazed by cattle that not a single plant exactly like the others could be found and even the parent was dead.” In his last letter, Ehrle clearly knew the plant was dead when he asked St. George to send him a section of the trunk, presumably so he could count the rings.

Despite its death, mystery still surrounds the cone-producing parent—namely that none of its offspring, after nearly a hundred years of cultivation, have ever been reported to produce seed. This includes the fifty-two year old specimen at the Arnold Arboretum that is over three feet tall as well as the one that Harold Epstein of Larchmont, New York, obtained from George Ehrle in the 1940s that was 18 inches tall by 22 inches wide in 1983. The sterility of cultivated specimens of ‘Minuta’, as well as his reluctance to provide Ehrle with any hard evidence of its existence raises some doubts about St. George’s claim that he had found the actual parent of the seedlings he sold to Ehrle. In my opinion, the most likely explanation is that the seedlings originated from cones produced by a witch’s broom on a nearby, normal hemlock.⁴

From start to finish, the story of ‘Minuta’ is a comedy of errors, including my own. Nevertheless, I’m pleased to report that when I asked St. George to send me cuttings from the dense, pyramidal hemlock in his yard, he generously agreed to do so. They arrived at the Arnold Arboretum on December 3, 1981 and I stuck them under a polyethylene tent in the greenhouse. Only one cutting from this accession survived to which I gave the cultivar name ‘St. George’. Forty years later, it has matured into a sixteen-foot tall monument to the man who discovered one of the truly great dwarf conifers.

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Peter Del Tredici worked in a variety of capacities at the Arnold Arboretum for 35 years and taught at the Graduate School of Design and at MIT for over 20 years. His recent work is focused on urban ecology and climate change.

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Endnotes

• 1 This statement is based on the mistaken assumption that Ehrle’s var. minuta had been collected “near Charlotte” because that’s where Daniel St. George lived.
• 2 According to the International Code of Nomenclature for Cultivated Plants, 9th ed. (Brickell et al., 2016), “An assemblage of individual plants grown from seed derived from uncontrolled pollination may form a cultivar when it … can be distinguished consistently by one or more characters even though the individual plants of the assemblage may not necessarily be genetically uniform.” (Article 2.12)
• 3 The checkered house is still there and its name refers to the diagonal, checkerboard pattern of its red and black bricks.
• 4 Seedlings produced by witches’ brooms are the source of many of the dwarf conifers. They are common in Pinaceae genera and Waxman (1975) has documented them in eastern hemlock.

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References

Abbey, F. 1967. Fifty years with lilies. The Lily Yearbook of the North American Lily Society 20: 112–120.

Bergman, H. (editor). 1965. Dwarf Conifers—A Handbook on Low and Slow-Growing Evergreens. Plants & Gardens 21(1): Handbook #47.

Brickell, C. D. et al. 2016. International Code of Nomenclature for Cultivated Plants, 9th ed. Scripta Horticulturae No. 18. I.S.H.S., Belgium.

Del Tredici, P. 1983. A Giant Among the Dwarfs. Theophrastus, Little Compton, RI.

———1984. St. George and the Pygmies. Theophrastus, Little Compton, RI

———2020. Closing the book on Sargent’s weeping hemlock. Arnoldia 78(2): 8–33.

Den Ouden, P. and B. K. Boom. 1965. Manual of Cultivated Conifers. Martinus Nijhoff, The Hague.

Gotelli, W. T. 1960. The Gotelli arboretum of dwarf and slow growing conifers. The American Horticultural Magazine 39(4): 185–198.

Jenkins, C. F. 1932–1951. The Hemlock Arboretum at “Far Country” Bulletin, 1–74. Germantown, PA.

Spingarn, J. W. 1965. Canada hemlock variants. The American Horticultural Magazine 44(2): 99–101.

———1969. A few new forms of Tsuga canadensis. American Rock Garden Society Bulletin 27(3): 85–90.

 Swartley, J. C. 1938. The eastern hemlock and its varieties. The National Nurseryman 46(6): 4, 10–11.

———1939. Canada Hemlock and Its variations. Master’s Degree Thesis, Cornell University.

———1946. A swing around the hemlock circle. American Nurseryman 83(7): 7-10; 83(8): 11–13.

———1984. The Cultivated Hemlocks (revised by H. J. Welch). Timber Press, Portland OR.

Teuscher, H. 1935. Tsuga canadensis minuta (var. nova). The New Flora and Sylva 7(4): 274–275.

———1949. Abbott’s pigmy hemlock. Plants and Gardens 5(3): 141.

Waxman, S. (1975). Witches’-brooms sources of new and interesting dwarf forms of Picea, Pinus and Tsuga species. Acta Horticulturae 54: 25–32.

Yerex, C. and E. L. Kline. 1961. The story of the Aurelian hybrids. The Lily Yearbook of the North American Lily Society 14: 54–60.

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