Winter Propagation – Random Notes

A recent Flora Wonder Blog entitled Pine Torsos gave tribute to the colorful trunks of various pine species. An afterword comment by a reader quizzed me about what rootstock I use to propagate Pinus bungeana. Normally, I don't respond to blog comments, not that I'm arrogant or indifferent, but because I'm not at all a social media kind of guy. Actually, I'm a little puzzled that I do a blog anyway...like, why do I feel the need to expound at all? I have a neighbor, less than a quarter-mile from my home, who installed a plastic reader-board along my Blooming-Fernhill Road, and who – whomever he is – posts such messages as “Drive carefully for motorcyclits” [sic], or “Have a Merry Christmas,” or “Remeber [sic] to vote,” where he apparently doesn't remeber how to spell remember. I asked my employee Seth, who also drives past this sign five days a week, why this light-weight, rong-spelling, philosopher/social commentator feels the need to inform or enlighten us with his wit and wisdom. Seth responded, “You mean, like you do with your blog every week?” Ooo...touche Seth; maybe it's time you update your resume.

Pinus bungeana

Pinus bungeana

Anyway, back to the rootstock question, the asker qualified his request with “Of course if it is not some kind of sekret?”* Of course not. I've been on this earth for 39+ years, and at this point I have neither secrets nor sekrets. I have used both Pinus strobus and P. strobiformis, but I prefer the former because it is much more winter hardy (USDA zone 3, -40 F) than the P. strobiformis (USDA zone 6, -10 F). Most of my customers are in colder areas, so for the past five years or so I abandoned the use of P. strobiformis. Mind you, I don't find anything to be a “perfect” rootstock for P. bungeana. The initial graft “take” is usually 90% or better, but five years later about 15% will perish, at least at Buchholz Nursery, and it doesn't seem to matter if the scionwood is from a full-size cultivar such as 'Silver Ghost' or a dwarf such as 'Diamant'. The death rate is about the same whether grown in containers with our high-priced permeable soil media, or in our well-drained field dirt. In any given crop one will find a few trees with yellow foliage. They are alive (sort of) and can even put out new growth, but they are ultimately doomed. I can't stand to look at them, especially since a visitor once commented when he saw a solo boxed specimen, that he “wasn't aware there was a golden cultivar of P. bungeana.” I suspect that the 3-needle P. bungeana would be more compatible with P. gerardiana to which it is closely allied, but that wouldn't be a hardy rootstock either. Or onto P. squamata (another lacebark), but I don't even have that species – it is the most rare pine on earth (from Yunnan, China); the recently discovered conifer consists of only 36 trees.

*Besides, a plethora of horticultural “sekrets” are already revealed in the recent publication of The Bench Grafter's Hand Book by Englishman Brian Humphrey (CRC Press). He adequately discusses rootstock-scion compatibility, including with Pinus bungeana, especially since the long-term viability of all grafting is the primary issue. His “science” is an on-going investigation with loads of speculation based upon a long, illustrious career. No propagator has all the answers, or at least I would never trust one who thinks he does. And believe me: I've met those types.

Metasequoia glyptostroboides 'North Light'

Taxodium distichum 'Falling Waters'

Larix kaempferi 'Twisted Sister'

We're in the thick of winter grafting now, this week after Christmas, with the deciduous conifers being our initial endeavor. They – Metasequoia, Taxodium and Larix – are clean and straight; they are perfect for the winter's grafting warm-up. Metasequoia would be a failure if 95% doesn't succeed, and our “take” has never been less; Taxodium and Larix ditto. The Larix effort has been limited to just three cultivar copulations – L. kaempferi 'Peve Tunnis', L. k. 'Twisted Sister' and L. decidua 'Puli'. I could have split it up further with other worthy cultivars, but the three that I chose to propagate will all sell in any case, so I decided to simplify. I described the 'Twisted Sister' in a previous blog “New” Conifer Cultivars, a University of Idaho Arboretum's recent discovery as a witch's broom mutation on a L. k. 'Diana'. In turn I have given a few away, but I'll probably be gone from this earth before the verdict comes in on its ultimate value to horticulture.

Pinus leucodermis 'Banderica'

Pinus leucodermis 'Banderica'

I'll admit that I've never had a properly-researched business plan, but I typically (annually) make a list of what scions to propagate for a certain rootstock – and my Master Plant List (MPL) assists me to not forget a particular cultivar. Without my list I would probably neglect to cut Pinus leucodermis (aka heldrechii) 'Banderica', the lustrous, attractive squat-pyramidal dwarf “Bosnian Pine.” But, ok, should we graft 50-100 of that, and then also do some Pinus leucodermis 'Beran Conica' as well? The two look identical to me – was there a nomenclatural mix-up at one point? Really, it doesn't matter what I propagate since my numbers are so small, and because I sell these plants at all sizes, from a one-year graft to a twenty-year-old tree, and there's a modicum of profit with all. Don't conclude that WOB (Wise Old Buchholz) is smug about sales, for I cherish every dollar that I exchange for my bushes. The bottom line is that I sell ornamental life, kind of a god-like function, and I choose the trees that humour me. The deal is that the propagator will be humbled frequently and sometimes considerably, but the overall reward if successful is greater than life is for the insurance agent or the car dealer. For the record our Pinus leucodermis 'Banderica' are grafted onto Pinus sylvestris.

Pinus contorta 'Frisian Gold'

Pinus contorta 'Taylor's Sunburst'

Pinus contorta 'Chief Joseph'

We finished grafting our 1,000 Pinus contorta var. latifolia rootstocks with 50 P. c. 'Frisian Gold', 200 P. c. 'Taylor's Sunburst' and 750 P. c. 'Chief Joseph'. The former two do fairly well concerning percentage of graft “takes,” but 'Chief Joseph' has stymied propagators for years, and combined with its slow-growing nature, it has remained highly sought after and expensive in the trade. It has existed for at least 20 years, and initially my two-fascicle (needled) Pinus sylvestris was my rootstock employed. Unfortunately my success percentage hovered around 30-35%, and so too for other companies which explains its rarity and high price. But, its popularity is understandable, as even Hillier touts it (2015 edition) as: “A slow-growing cultivar with light-green foliage becoming an eye-catching vibrant deep yellow in winter.” I love the superlative: “eye-catching vibrant deep yellow” which cannot be improved upon...well, until March when, in Western Oregon, and I suppose in soggy England as well, our mutual wet-winter climates cause a needle-crud-burn, and the cultivar can look dreadful until new growth emerges in April. But, I'm happy to report that we switched about five years ago from Pinus sylvestris to Pinus contorta var. latifolia – the “Lodge-pole pine” – and our percentages increased to around 50-55 percent graft success. I would do a couple thousand more 'Chief Joseph' grafts each year except I don't have the scionwood, and that's because my larger plants are in such high demand (and price) that I sacrifice them for immediate profit. I've said it before, that the sales department at Buchholz Nursery is constantly at odds with the propagation department, but the perplexing truth is that I head both entities.

Chief Joseph

Allow me to now take a minor swipe at the Royal Horticultural Society, and its connection to The Hillier Manual of Trees and Shrubs publication (2019), when Pinus contorta is described as “Douglas ex Loudon Beach Pine... blah blah blah...It is a vigorous species, used for fixing sand dunes in maritime areas.” After that description is the inclusion of 'Chief Joseph' as if it is a member of the “Beach pine/sand dune” tribe. It is not. 'Chief Joseph' was discovered 300 miles to the east of any beaches or sand dunes. In fact it seems remarkable to me that the hardy P. c. subsp. latifolia is included in the same species as the “Beach pine,” P. contorta subsp. contorta. Hey – I'm not the botanist in any of this, but be clear that old 'Chief Joseph' never ever travelled west to see the “beach.” The Manual is correct that the cultivar was “Discovered in the Wallowa Mountains, Oregon, USA...and named after the famous leader of the Native American Nez Perce tribe,” but the variable Pinus contorta species and its cultivars should be more clearly defined. After the initial confusion (flub) Hillier continues: “var. (or subsp.) latifolia Englem [Engelmann] Lodgepole pine. A medium-sized tree, less vigorous than the type and with slightly broader leaves...” I agree that it is less vigorous, which is why I initially eschewed it in favor of the far more vigorous (and horticulturally adaptable) rootstock of Pinus sylvestris – even though the latter is highly variable also. As far as “slightly broader leaves” I would like to see a factual comparison because that is a dimension that I've never noticed.

The common name of “Lodgepole pine,” according to Hillier “derives from its use by Native Americans as the central pole of their huts.” Mountains of W. North America. I about 1853 [much later than David Douglas] by John Jeffrey.” Central pole – Ha! If placed in the center then the teepee would burn down, for the essential fire was positioned in the tent center and the occupants lay as wheel-spokes with their feet closer to the warmth, and where the fire's smoke could escape through the opening at the top. Where did Hillier get its Native American dwelling information? Instead, watch a few Hollywood Western movies. The specific epithet contorta was rendered because of the beach trees' bent, twisted branches and slightly curved needles.

Picea pungens 'Gebelle's Golden Spring'

Picea pungens 'Gebelle's Golden Spring'

To propagate Pinus contorta 'Chief Joseph', the choice seems to imply that, for best success, one should employ a rootstock that is the same species as the scion, i.e., a Pinus contorta should be attached to a P. contorta rootstock, or, let's say, a Picea pungens cultivar should be placed upon a Picea pungens seedling rootstock. I find this “rule” to have profound exceptions. For a few years, earlier in my career, I accepted the same/same notion with Picea pungens cultivars, and I hooked them upon “Colorado blue spruce” seedling understock, but the subsequent propagule performance was less impressive than with the P. pungens cultivars grafted – at the same time by the same grafter – upon Picea abies, the hardy “Norway spruce.” Picea abies is more adaptable (as when grown in container culture) and more vigorous than Picea pungens, so why not go “Norway” and utilize a more vigorous and hardy root system? I can point to some older P. pungens cultivars – on P. abies – in my collection that demonstrate no problems or incompatibility after 30-40 years. Nevertheless, I have no explanation why our Pinus contorta var. (or subsp.) latifolia on its own rootstock produces a higher graft “take” than with the more vigorous, more adaptable rootstock of Pinus sylvestris. Almost all other pines are considered “easy to produce.”

Abies firma 'Halgren'

As for the “True firs,” Abies cultivars, I placed my understock order from a seedling producer for a couple thousand Abies firma seedlings in pots. I only received 500, as the rest of his crop was too small, and even the understock I received is barely acceptable for some thin-stem dwarf cultivars. A fat-scion Abies concolor selection, or a typical Abies procera scion does not combine well with skinny rootstock. Of course, a successful “take” can be had, but one would have to use a small-caliper scion twig, and while the propagator can achieve a viable connection, the grower will be saddled with a wimpy crop that lingers. The lingerers are too costly to throw out, but dealing with them for an extra year or two will bring you little or no profit. We'll use our small rootstock to graft a few different Abies koreana dwarves, or just graft the lot with Abies koreana 'Ice Breaker'...and eventually they'll grow to salable size.

Abies firma 'Nana Horizontalis'

Now, I could have accepted different Abies rootstock this past year, for (in my experience) all Abies species are compatible with each other. Abies balsamea, and even better, A. balsamea var. phanerolepis could have been purchased, but at this point in my career I just don't have employees (either focused or committed enough) to complicate the propagation effort by keeping track of various rootstocks. Most of my customers prefer the USDA zone 5-6 Abies firma rootstock over all others because it can withstand the warm, humid conditions in America's central and northeast and southeast locations, and customers are willing to pay extra for this preferred rootstock. Recently we have added Abies firma produced by our own rooted cutting program, and after the cuttings are “stuck,” three or four years later most are of graftable size. The problem is that we have many customers who are willing to buy our Abies firma in pots...before we ever get them up to size to graft. Often, a dollar today is more attractive than maybe two dollars tomorrow.

Abies firma "flower"

So, what's with this Abies firma, why is the USDA zone 5-6 Japanese species so desirable, why is it preferred over more winter-hardy choices? Little can be gained from the North Carolina Extension Gardener website, where the proffered description includes: Flower Bloom Time is “Spring,” then the following Flower Description is “No flowers.” Conifers flower of course, but not in the technical botanic sense, that I accept, but the contradictory attribute-descriptions are not helpful. The species was first described by Siebold/Zuccarini in Flora Japonica 2^nd edition, and the epithet refers to the conifer's “stiff” needles. Well, I don't find them to be particularly stiff, at least compared to other Abies species, but it is an epithet that we are forever stuck with. However, in Japan, the wood is used in construction and for the making of coffins, and in neither case would one want to substitute for a species more weak or flimsy. Firma occurs throughout southern Japan, at least in Honshu, Shikoku, Kyushu and even on Yakushima, from nearly sea-level to 6,000' in elevation, and it is noteworthy as an Abies that can withstand a variety of climatic conditions. In Japan it is known as Momi, which simply translates as “fir.”

When I quizzed my Japanese wife as to the meaning of “momi,” she immediately sang out the “Oh Christmas tree, Oh Christmas tree” song in Japanese:

♪ Momi no ki, Momi no ki ♫~
Itsumo midori yo ♪
“Firwood, firwood
Always green.”

When pressed further she wondered if divorce from me might be preferable to the groaning task of enlightening the Flora Wonder Blog readership, because I insisted that “momi” must have a word origin. With some trepidation she suggested two, then three, then five possibilities (but made sure that I acknowledged there could be another five or perhaps fifty more suitable explanations):

1) In a forest two trees may look like they're rubbing together when the wind blows. That action is called momu. Somehow momu became momi.

2) Abies firma cones ripen and fall to the ground. Moroi mi means “fragile fruit.” It was shortened to momi which is much easier to say.

3) Metomi means “so many new shoots,” from meto (growth) and mi (wealth). Shortened from metomi to momi, because, again, momi is easier to say.

4) Moegi is color (iro), a light yellow-green.

5) The “momi fir” is considered a “sacred tree,” which is omi no ki, again shortened to “momi.” A book of Japanese poems was compiled from 629-759 AD, called Manuoushu, which first presented omi no ki.

Haruko believes that 5) is the most likely. I gave her a long hug, and our divorce has been postponed.

Obviously my grafters don't bog (or blog) themselves down with word origins or with rootstock/scion compatibility, rather they perform for a paycheck primarily, and if I supplied dog-turd scions to graft upon horse shit, they would perform the task without thought. Employees are functionaries, programmed to “do,” not to question or appreciate the details of their task. If any ideas are trialed or eventually adopted, the initiative depends upon me entirely; a sad situation surely, but one that I've been forced to accept. My attempts to engage them only leads to nervousness and confusion, so from that point of view I've had a solo career.