Friday, March 27, 2020


Cedrus atlantica 'Glauca'

I had never encountered the word glauca in my life until my early 20’s when I began my career in horticulture. The plant in question was the “Blue Atlas cedar,” Cedrus atlantica ‘Glauca’, so I supposed that glauca meant “blue.” Then, after reading thousands of plant descriptions in books such as The Hillier Manual of Trees and Shrubs, Bean’s Trees and Shrubs Hardy in the British Isles and Krussmann's Manual of Cultivated Conifers I learned that glauca was more accurately defined as a light bluish-gray or bluish-white color. With conifers it often referred to a plant who’s needles have a powdery or waxy coating that gives a frosted appearance, but a coating that can be rubbed off. I remember a vicious winter at 0 degrees F with 45 MPH winds because the cold snap blew the coating off the prevailing windy side of our “Colorado Blue spruce” cultivars. Yep: they were thus variegated blue and green until glaucous foliage developed again in spring.

Picea pungens 'Iseli Fastigiata'

The word glauca (same root for glaucoma) is from Latin glaucus and that from Greek glaucos meaning “gleaming” or “gray.” The term was also used to describe a range of pale colors, even yellow-green. A person with fair hair and blue eyes is known as a glaucope (if fair hair and brown eyes a cyanope.) There are a plethora of plant cultivars named ‘Glauca’, but ever since 1959 the International Code of Botanical Nomenclature (ICBN) forbids the use of Latin with plant names. Nevertheless a number of nurserymen are unaware of the rules, and there are others who don’t give a damn about some questionable EuroCode anyway. An example would be Picea pungens ‘Glauca Fastigiata’ where both cultivar words are derived from Latin. This selection was originally introduced in the 1970’s as ‘Iseli Fastigiate’ or ‘Iseli Fastigiata’. It is not against the ICBN rules to use one’s name for a cultivar – such as Iseli – but it is in pompously bad form to do so, and you would never encounter a name such as ‘Buchholz Purple Ghost’ for one of my maple introductions.

Picea glauca 'Blue Tear Drop'

I’m far from being the Noah’s Ark of the floral world, but even at our relatively small nursery size we have about 90 different varieties with glauca in the name, with half of them being Picea glauca (the “White spruce”). Note from the list below that all except Lindera glauca and Rosa glauca are conifers.

Abies concolor 'Glauca Compacta'                                            Pinus parviflora 'Glauca'
Abies koreana 'Glauca'                                                              Pinus pumila 'Glauca'
Abies lasiocarpa 'Glauca Compacta'                                         Pinus sylvestris 'Glauca Fastigiata'
Abies pinsapo 'Glauca'                                                              Pinus sylvestris 'Glauca Nana'
Abies procera 'Glauca                                                               Pseudotsuga menziesii 'Glauca'
Abies procera 'Glauca Nana'                                                     Pseudotsuga menziesii 'Glauca Hesse'
Abies procera 'Glauca Prostrata Hupp'                                     Pseudotsuga menziesii 'Glauca Pendula'
Abies veitchii 'Glauca                                                                Rosa glauca
Cedrus atlantica 'Glauca'                                                          Thuja koreana 'Glauca Prostrata'
Cedrus atlantica 'Glauca Pendula'                                            Thuja orientalis 'Minima Glauca'

Rosa glauca

Let’s start with the two non conifers, and though we currently sell neither, I still find them interesting members in my collection. Rosa glauca was not named for bluish flowers as you can see, but rather for the gray-blue leaves. I would grow it for the foliage alone because the pinkish-red flowers aren’t much anyway. While the hip (fruit) is dark red that still doesn’t explain the old synonym of Rosa rubrifolia, meaning “red leaves,” unless one considers the new growth’s color. Anyway the hardy (USDA Zone 2-3), scrappy-looking shrub is deciduous and native to the mountains of central and southern Europe. I find the species kind of wild-looking, and not really suitable in a neat, refined garden; maybe planted against a rough wall or fence in full sun would show it to best effect. In the Hillier tome it is given a greater thumbs-up and is declared “Invaluable for coloured foliage schemes.”

Lindera glauca

Lindera glauca

The Lindera genus – named for the Swedish botanist Johann Linder – has had representative species in my garden since the beginning. I used to propagate and sell them but the reality is that they were never really popular – yet another genus that I would describe as underused. That’s a shame because the 80-100 species of evergreen or deciduous trees (or shrubs) are aromatic with small flowers noticeable en masse, followed by tiny, shiny black berries and beautiful autumn foliage. L. glauca has long, narrow green leaves – and I am a fan of the skinny – that are glaucous beneath, hence the specific epithet. It is native to China, Korea, and Japan and was first described by Siebold and Zuccarini. Hillier mentions that in China this and other Lindera species are “used in the manufacture of incense sticks (joss sticks).” I have one specimen left which is growing in a “natural” environment down by the pond, and it receives no attention, including irrigation. I admire the long-lasting peachy-orange color in autumn; then with the onset of winter the leaves turn to a delicious mocha color and actually persist until new growth pushes them off in spring.

Abies veitchii 'Glauca'

Abies veitchii was first discovered by J.G. Veitch on Mount Fuji, Japan, in 1860, then collected for the Veitch firm by Charles Maries in 1879. I had a specimen in the Display Garden, but over the years it was picked on and drilled relentlessly by sapsuckers until it grew so unsightly that I eventually cut it down. I was further into my career before I discovered a magnificent specimen of Abies veitchii ‘Glauca’ at the Porter Howse Arboretum of Sandy, Oregon, and owner Don Howse kindly shared scions with me. The cultivar receives scant notice in the literature, and Rushforth in Conifers boringly refers to the needles as “somewhat gray-blue.” A more vibrant description is provided by Auders/Spicer in the RHS Encyclopedia of Conifers where it’s called “a selection with steel-blue needles.” I think that is a more exciting description, but when one looks up at the foliage it is the vivid silver color of the needles’ undersides that is powerfully impressive, not the top color. According to Auders/Spicer it originated in Germany before 1968, but they add that “This name in Latin form is only acceptable if proved to have been published before 1959.” Hopefully the namer didn’t run afoul of the ICBN authorities.

Cedrus atlantica 'Glauca Pendula'

Cedrus atlantica ‘Glauca Pendula’ is validly named, as the weeping version of the “Blue Atlas cedar” was discovered in France and the name was coined in about 1900. Or, maybe not validly named since the Cedrus genus was once thought to include four species but now some botanists insist there are only two: C. deodara of the Himalaya and C. libani of the Mediterranean. If that’s correct, one should call it Cedrus libani subsp. atlantica ‘Glauca Pendula’. I know – only plant nerds like me would care about those details. I first encountered it in a corner field at the first nursery where I worked… where it was sprawling unattractively with no apparent purpose. Later I learned that you could train it into any form you wanted, and, when I was finally in business, I had a narrowly-weeping crop that rose to 15’ tall before I sold them. The selection is certainly not “dwarf” and it didn’t take long to attain such height. In another case I trained one sideways, where each year’s 2-3’ of growth humped along in serpent form. One customer was intrigued with my ten-year (ten hump) creation and couldn’t live without it; and since I needed money I sold it to market. I used to graft a couple thousand of ‘Glauca Pendula’ per year back when we did custom liner production, but demand for it eventually declined and we haven’t grafted a single one for over a dozen years. I realize – just now – that I didn’t keep even one specimen on the property, but thanks for the memories.

Cunninghamia lanceolata 'Glauca' 

I want to champion Cunninghamia lanceolata ‘Glauca’ which I website-describe as “An evergreen conifer with a broad pyramidal form. Leaves are bright blue and very sharp. Ornamental reddish brown bark is deeply furrowed…etc.” It is commonly known as the “Blue China fir” and is supposedly more hardy (to USDA Zone 6) than the typical green of the species. The “China fir” can grow to 150’ in height but my grandmother had a hedge of the green version that was annually pruned to only six feet tall, and the sharp, poky foliage definitely kept the neighbor’s children off her property.

Cunninghamia lanceolata 'Glauca' prostrate form

A form of Cunninghamia lanceolata ‘Glauca’ that was entirely prostrate was growing at Arrowhead Alpines in northern Michigan. First of all, I was surprised that the species could even survive there, but I was suspicious about the “flat-growing” specimen. I obtained a start of it – with their enthusiastic encouragement – but my propagules quickly assumed an upright habit. I suppose that in frigid Michigan their plant had “learned” to hunker down to survive the winter. I believe that all plants are unique individually even if they are members of the same species; in other words: some cultivarious members are more tough and resilient than others and some shiver in the cold wind more than their brethren. “China fir” should not survive in northern Michigan, but since one does it gives other plantsmen the hopeful idea that we can and should expand our domain.

Pinus sylvestris 'Glauca Fastigiata'

Nurserymen – I included – used the grow the old cultivar Pinus sylvestris ‘Glauca Fastigiata’, the narrow blue-green pillar that Hillier describes as in “the shape of a Lombardy poplar.” I discontinued it due to its propensity to splay open with just a few inches of wet snow. Even the old Dutch geezer that I used to work for had the cultivar planted as a pair at the front end of this propagation house, and every winter with the threat of snow we barber-poled the specimens with twine to keep them intact. Really, garden-worthy cultivars shouldn’t need artificial support to thrive – let alone survive in a successful landscape. Nevertheless I have encountered “crutches” in some gardens that help ward off old age and gravity with the trees, whether they be ornamental cherries, pines or ginkgoes. At a certain point we all need a helping hand I guess. Anyway, selections of the “Fastigiate Group,” as Hillier calls them, were promoted as early as 1856. I haven’t propagated a single ‘Glauca Fastigiata’ for over 30 years, yet nearly every week I drive past one in front of the bank at the entrance into nearby Hillsboro, Oregon.

Picea glauca 'Pendula' 

Ah – Picea glauca ‘Pendula’, the narrow “Weeping White spruce” : one of the most garden-worthy conifers ever. Perhaps the most bizarre and unforgivable omission to The Hillier Manual of Trees and Shrubs is for Picea glauca ‘Pendula’. How could you ever – in 2014 – not mention it ahead of the old-Latin-Euro cultivars of ‘Coerulea’, ‘Densata’, ‘Echiniformis’ or ‘Nana’? Picea glauca ‘Pendula’ is now produced by the many thousands… as it should be. It supposedly originated in the 1860’s in Versailles, France as a mutation and was formally described by the French botanist Carriere in 1867, according to the American Conifer Society’s website. I don’t know, there are a number of weeping selections for all of the Picea species, and we grow another weeping Picea glauca named ‘Canadian Weeper’ from a 1980’s collection from Nova Scotia. Every morning I stand at the kitchen window and look out at the landscape, and my pillar Picea glauca ‘Pendula’ dominates the near distance at about 30’ tall. Both doves and red-tailed hawks have perched on its top, and occasionally snow or ice frosts its gray-blue branches. Definitely, nature gets an A+ for this creation and I have kept the family fed from the sales of it.

Sequoiadendron giganteum 'Glaucum' (From Buchholz left and Bedgebury right)

Normal Sequoiadendron giganteum cone on left, 'Glaucum' on right

The tallest plant in my original Display Garden is Sequoiadendron giganteum ‘Glaucum’ and I look at it now from my office window – yes, I hogged the desk with the best garden view. The distant sight from the window wasn’t the close experience I wanted, so I just went outside to stand next to the trunk. I suppose the specimen is 80-100 feet tall – and I am pretty good at estimating trees’ heights. It is exactly 39 years old, grafted onto a three-year green seedling rootstock. The best feature, from a landscape point of view, is the narrow form, and I remember the impressive blue pillar at the Bedgebury Arboretum in southern England which was over twice the size of mine. Hillier in 2014 relates that their tree “has reached just over 25m in the SHHG (2013)” and that it was introduced to cultivation around 1860. If so, I wonder where the champion could be found? Actually I don’t buy the Hillier story about an 1860 introduction since blue (glaucous) seedlings have arisen by the hundreds over the years and I have grown many myself. But the narrow ‘Glaucum’ is truly unique regardless of when it was first cultivated. Another nursery’s description of ‘Glaucum’ suggest that it grows “slower than the type”… but hmm… I don’t think so. One difference, however, is that ‘Glaucum’s’ cones are only half the size of those from the normal green trees. If there was only one species in the world where I could stick my chest out and boast I know more about it than anybody else it would be with the “Giant Redwoods.” Believe me. I grew up in a house with two massive 1873-planted specimens and my first plant sales ever – I guess I was about 8 years old – was Giant redwood cones to florists in Eugene, Oregon, thanks to my grandmother’s assistance with driving me around town to the shops.

Pseudotsuga menziesii 'Glauca'

Pseudotsuga menziesii 'Glauca'

Nomenclaturally questionable is Pseudotsuga menziesii ‘Glauca’ which was popular when I began my career. As with the Giant redwoods there are many selections of the “Blue Douglas fir,” and so the botanical designation should probably be Glauca group. Then, keep in mind that var. glauca refers to the eastern-most range of the species native to the Rocky Mountains down and into Mexico, a variety that is more hardy, but more slow-growing than the green version native to my nearby woods. Besides the beautiful blue foliage, the var. glauca features cones that can be pinkish in spring, and they are smaller and more pointed than the far-west’s larger and more rounded brown cones. As I mentioned earlier, Douglas fir cultivars were popular at the beginning of my career, but eventually sales dwindled. I think the problem was that Oregon nurserymen (including myself) were grafting the blue, the narrowly blue, or the weeping blue cultivars onto the less hardy green rootstock, and cold-USA-area garden centers grew tired of returning refunds for insufficiently hardy trees.

If only one color was used to describe the earth’s flora, of course it would be green. Plantsmen, however, have seemingly grown bored of green and we champion other foliage colors such as yellow, red or blue. From a business point of view, red maples always outsell the typically green selections, and blue conifers are horticulturally more in demand than green. I make a living off the abnormal, the freaks, the different. That’s kind of weird, isn’t it?

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