Friday, May 22, 2020

Plump Pyramids

Abies procera 'Glauca Prostrata' – oops!

The Flora Wonder Arboretum is filled with plump, pyramidally-shaped plants, especially with the coniferous species. So often the “dwarves,” which are touted as miniature garden denizens, actually grow quite large – at least for this old nurseryman – and a plant that is/was initially described as dwarf, or globose or spreading can with age assume a plump pyramidal form. Don't be fooled with the cultivarious monikers of 'Nana', 'Pygmaea' (Pygmy), 'Gnome', 'Midget', 'Munchkin', 'Minima', 'Spreader', 'Prostrate' etc...for they can all grow into strong, upright specimens.

Picea omorika 'Nana'

In spite of that, some conifers are “relatively” true-to-form, and they bless our gardens with a year-round structural presence. For example I have a glittery dense pyramid – Picea omorika 'Nana' – that was for years a dwarf round ball; but now, after nearly half a century, it's currently a 15' tall fat pyramid that has unfortunately created a water-shadow problem with the nearest irrigation sprinkler. The specific epithet of omorika is the Serbian name for “spruce,” while the generic name of picea is Latin for “pitch” for the resin in the bark. Despite the species origin in southeastern Europe, the cultivar 'Nana' originated as a witch's broom found about 1930 in Boskoop, The Netherlands.

Abies nordmanniana 'Golden Spreader'

My oldest specimen of Abies nordmanniana 'Golden Spreader' used to have a low spreading form, but eventually – with no help from me – it developed an upright pyramidal shape and is already 10' tall. It is growing in the rock garden in full sun and has never burned, even though some experts claim it requires afternoon shade to prevent sunscorch. 'Golden Spreader' is particularly effective in the winter garden as it emits a warm golden glow even on cloudy days. The nordmann species, or “Caucasian fir,” was discovered by Alexander von Nordmann (1803-1866) and was introduced into western Europe in 1838. It is grown by the thousands in Oregon as a Christmas tree as it is relatively fast growing for a true fir, and also because it retains its needles for a long period. Rushforth in Conifers claims that silver firs “will keep them [the needles] four to five years, but I [Rushforth] have counted live needles 26 years old on Caucasian fir.” I'm impressed with such committed long-term observation.

Pinus cembra 'Blue Mound'

Long ago, if I remember correctly, a conifer aficionado from Washington state called to chat about Pinus cembra 'Blue Mound', and I think he implied that it was his dwarf discovery. I never saw the original, but I'm sure it was appropriately named: for a miniature blue mound. But as I frequently admonish, you can't expect the propagules to appear the same as the original seedling because they are grafted onto vigorous rootstock, probably Pinus strobus, so all of my 'Blue Mound' specimens have grown into plump pyramids. I've even seen 10' tall trees at another nursery where candle pruning probably does not occur. Linnaeus coined the specific epithet cembra which was named for a commune in Trentino in northern Italy with a population of about 2,000 (pre-covid) souls. The common name for P. cembra is “Arolla pine,” and that's for a village in the canton of Valais in Switzerland. In The Garden (1904) it states: “The Arolla is an Asiatic tree brought to us during the glacial epoch that reigned throughout Europe for hundreds of millions of years. Its place of origin is probably northeastern Siberia where it is quite at home, forming immense forests...,” and indeed we used to grow P. cembra var. siberica. I have a number of P. cembra cultivars but I've never seen the species in the wild, but apparently Hillier has, and in his Manual of Trees and Shrubs (2014) it states that it is “An ornamental tree of almost formal aspect which has distinct landscape possibilities.”

Pinus bungeana 'Temple Gem'

Pinus bungeana 'Temple Gem' 

Pinus bungeana 'Temple Gem' is an early Buchholz introduction, discovered as a seedling growing at about one-fourth the rate of the type. I named it 'Temple Gem' because the northeast Chinese species was first seen by Dr. Bunge in a temple garden near Beijing in 1831. It was introduced to horticulture in 1846 by Robert Fortune, the Scottish botanist and plant explorer, more infamously known – from a Sino point of view – as the thief of tea plants (Camellia sinensis) and tea processing information from the Chinese. I used to grow a lot of conifer species from seed and I estimate that the original 'Temple Gem' is about 35 years old and is now a broad 14' pyramid. I remember about five years ago sitting down to rest on a bench at the University of Tennessee Arboretum. The bench was in front of a bushy form of Pinus bungeana, and I eventually got up to find an identification label. To my utter surprise it was 'Temple Gem', but I know that I didn't send it to them and I don't know who did; nevertheless the find invigorated me.

Picea breweriana 'Emerald Midget'

In our Short-Road section near the dwarf bungeana is Picea breweriana 'Emerald Midget', another early Buchholz introduction of seedling origin. For some reason it has prospered even though the type struggles in my region on its own roots. The “Brewer's Weeping spruce” is native to southern Oregon and northern California and has adapted to the mountainous, rocky serpentine soils. That doesn't matter if you graft the species onto Picea abies, which is actually better for container or field culture, and you don't lose any ornamental quality by doing so. I admit that I started this blog somewhat critical of plant names such as 'Gnome' and 'Midget' etc., yet I have done so myself with 'Emerald Midget', which at 35 years of age has grown to 12' tall. I should point out also that it doesn't really display the “weeping” appearance, and that the needles' silvery undersides are more on display than with the type. In fact, a conifer “expert” from The Netherlands (E. Smits) questioned me about 'Emerald Midget's' specific identity, that he and other cognoscenti were certain that it was, in fact, a Picea omorika, not a Picea breweriana. I won't question their overall expertise, the buds of the two species; really focus on them and you must conclude that it is a P. breweriana. Really, do I have to do your homework for you?

Picea glauca 'Blue Teardrop'

I collected Picea mariana 'Blue Teardrop' about 15 years ago, and speaking of “doing one's homework,” I later discovered that the cultivar is more certainly a member of the Picea glauca tribe, so I was required to change/correct hundreds of labels...which further bewildered my already confused employees. In any case 'Blue Teardrop' is an appropriate name, and the selection provides a solidly formal, slow-growing dense evergreen for the landscape, one that can be most appreciated on dire winter days. Interestingly, Picea glauca var. albertiana conica, even the blue selections, are fairly easy to root, but the dwarf 'Blue Teardrop' is not, at least not for me. The selection was made at the old Mitsch Nursery in Aurora, Oregon as a sport of P. g. 'Echiniformis', a cultivar that frequently reverts.

Sciadopitys verticillata 'Picola'

Just outside the office door is a group of Sciadopitys verticillata 'Picola', a dwarf form with a broad pyramidal habit. It originated as a seedling selection before 1980 at the Bohlje Nursery of Westerstede, Germany. 'Picola' can be replicated easily by grafting onto seedling rootstock, but it can also be increased by rooted cuttings, which are neither easier nor more difficult than any other “Umbrella pine” cultivar. We used to have better rooting success earlier in my career, but back then I had a very skillful propagator who is no longer with me. We use a stronger hormone with Sciadopitys than with other conifers, and even though the cutting will strike roots, water management under mist is crucial as the needle whorls don't easily shed the water and the center bud can rot. The stem is unable to push another growth bud, and even keeping the cutting on life support for another 2 years will not accomplish a miracle. In the distant past, and this year also, we attempted additional measures such as soaking the cuttings in water for 24 hours before planting. We're ever hopeful and keep on trying, but honestly I would gladly accept a 50% success rate, and also I would love to have my old propagator back.

Sciadopitys verticillata 'Fatso'

Buchholz Nursery also selected a more-dwarf (than the type) Umbrella pine and we named it 'Fatso'. I discovered, however, that our grafts would push vigorous growth and a few years later we would just have a regular-looking Sciadopitys, unlike the better behaved 'Picola'. I planted our specimen by the office where it looks good, but we haven't propagated it in at least 10 years.

Chamaecyparis obtusa 'Kosteri Fast Form'

Where space allows, Chamaecyparis obtusa 'Kosteri Fast Form' is an attractive evergreen conifer of dense pyramidal habit with cupped olive-green foliage. The selection originated as a more vigorous mutation of C. o. 'Kosteri' (obviously) which is itself a choice slow-growing cultivar. There also exists in the trade an 'Oregon Crested' cultivar which may or may not be the same as 'Kosteri Fast Form', but in any case they look the same.

Ginkgo biloba 'Chi chi'

Ginkgo biloba 'Chi chi' is a wonderful semi-dwarf selection with a dense, broad pyramidal form. Cuttings in summer root readily under mist, and we can achieve a 6-8' tree in about ten years. I have a 25-tree hedge planted next to my back yard and it's quite a sight to behold in autumn. We had grown 'Chi chi' for a number of years, then about ten years ago I was convinced by someone (whom I now don't remember) that the name should be 'Tschi tschi', so we changed all of our labels and sold them the new way. My wife Haruko disapproved because that was not a valid Japanese name, and that it was possibly Chinese. Anyway we're now back to 'Chi chi' which means “breasts” in Japanese, and chi chi also means “breasts” in Spanish, or at least in Mexican Spanish. The genus name Ginkgo is actually a mistake in translation spelling; it should have been the Japanese gin meaning “silver” and kyo meaning “apricot” due to the edible white seed which is hidden inside the vomit-smelling outer flesh. Fortunately 'Chi chi' is a male clone, although ginkgoes have been known to change sex.

Picea glauca 'Daisy's White' 

May is the month of glory for Picea glauca 'Daisy's White', a dwarf pyramid that features cream-white new growth. It originated as a mutation on P. g. 'albertiana conica' that was discovered by L. Jeurissen-Wijnen from Belgium, which explains why it was originally named 'J. W. Daisy's White'. Daisy is his granddaughter's name. The colors change throughout the season beginning with butter-yellow buds which contrast with the green of the older foliage. Then the color changes to a yellowish white, and then to green in summer. According to Promising Conifers from the Nederlandse Coniferen Vereniging, “This pearl should be placed somewhere in the half-shadow...[it] can be used for many purposes in a small garden, a heath garden, on cemeteries, in a rock garden or on a balcony or terrace. Alas this plant can have problems with plant louse and red spider.”

Sequoiadendron giganteum 'Little Stan' 

Sequoiadendron giganteum 'Little Stan' is a dwarf, dense pyramid consisting of juvenile foliage, bright blue-green in spring, hardening to a gray green by summer. This cultivar was discovered by nurseryman Nelis Kools from Deurne, The Netherlands and was named for one of his nephews. Nelis's nursery holds the Dutch national collection of Sequoiadendron, Sequoia and Metasequoia, no easy feat since his property is not that large. The plant can burn in winter in Oregon when it is young, but after a few years in the ground – in full sun – it can tolerate the weather. 'Little Stan' originated as a seedling, and it's fascinating that the cute dwarf came from a parent that is a member of the most massive tree on earth. However, I had one planted in our Conifer Field where I hadn't paid any attention to it all spring and summer a few years ago. To my shock I noticed one day that it had bolted from the top and produced a 4' normal Sequoiadendron leader, completely different from the juvenile foliage at the base. I informed Nelis about the situation and found it strange that a seedling could do that, when we both are familiar with cultivars from witch's broom origin that can revert back to normal. I threw out that particular tree but we still propagate and sell 'Little Stan', and they are produced easily by rooted cuttings in winter. One could graft it too, I suppose, but that might make it even more likely to revert.

Abies concolor 'Archer's Dwarf'

Abies concolor 'Archer's Dwarf' is a very garden-worthy cultivar, but it must be placed with excellent drainage. It will be rather globose when young but eventually will assume a pyramidal shape. The needles are unusual for an Abies concolor in that they are more fine than normal and also they are slightly sickle-shaped and point towards the main stem. 'Archer's Dwarf' was introduced by Gordon Haddow of Kenwith Nursery, England, and was named for the discoverer J. W. Archer from Farnham, England.

Tsuga canadensis 'Bergman's Heli'

Tsuga canadensis 'Creamy'

Tsuga canadensis 'Betty Rose'

I just walked through the original Display Garden and three mature Canadian hemlocks are planted near each other, all with pyramidal forms. Each is seldom encountered at their sizes, but they have all been through a lot of growing seasons. The foliage on Tsuga canadensis is delightful in May, so fresh and clean-looking. 'Bergman's Heli' is one we no longer propagate, but today I wonder why not? We continue to propagate 'Creamy', but when they're sold in one-gallon pots the form is low and spreading. The same for 'Betty Rose', but you can see that they both eventually grow upward. The 'Betty Rose' is considered a “miniature” but my 40-year-old specimen is nearly 10' tall now, and I'll bet that it is the largest in the world. The original plant was discovered in Maine by Francis Heckman of Pennsylvania. According to John Swartley's The Cultivated Hemlocks, “'Betty Rose' is the dwarfest of the white-tipped hemlocks, a very striking plant and a favorite of the author.” A favorite of this author too.

I don't want to overstay my welcome with excessive verbiage, but the plump pyramids are in their prime in May and they are best seen in person. The Flora Wonder Arboretum is somewhat of a prison for me, a beautiful one however.

1 comment:

  1. Love it! In the last picture of the Flora Wonder that front left tree looks like it has a smily face with beady little eyes from that angle, lol.