Flora Wonder Blog: Summer Maple Propagation, Part 3

Acer palmatum 'Celebration'

Acer palmatum 'Strawberry Spring'

Acer palmatum 'Geisha Gone Wild'

Our summer grafting agenda has reached the panic stage, which it has done annually for most of my 50 commercial nursery years. The owner or management begins to tabulate the total number of grafts completed, then projects ahead to what's left to do. Then math calculates the work days left – which are not seven days per week – until the completion date desired. The dreaded facts then reveal that, at x amount the crew averages per day, we'll only accomplish two-thirds of the task. That creates anxiety where I used to wake up at four in the morning, and the only relief was to hurry out at daybreak and cut as many scions as possible before the grafters arrived. Somehow that would settle me. Then you adjust your priorities and perhaps train a new grafter, but of course that delays the completion of other vital nursery projects. You could pay the crew an incentive to begin an hour earlier (which we always do), or to work full days on Saturday…or most likely, you "extend" your original completion date. The problem with the latter is that the success rate traditionally diminishes the longer we went. Reality forces us to compromise.

Acer shirasawanum 'Aureum'

Acer shirasawanum 'Moonrise'

Acer shirasawanum 'Plum Wine'

At any rate we need to get more numbers behind us, and the scion list, which I compile after scouting all the possible locations, includes many of the easy-and-quick to cut cultivars that we have in abundance. They are also the varieties where we usually achieve a high success rate, so at least we'll have some money-making inventory in stock for the future. Popular choices, where we have never had too many, include Acer palmatums 'Celebration', 'Strawberry Spring', 'Geisha Gone Wild', and Acer shirasawanums 'Moonrise', 'Aureum' and 'Plum Wine'. Note that four of the above six mentioned cultivars are Buchholz introductions, as MrMaple's clientele for some reason prefer our more unusual selections over the common tried-and-true red uprights and laceleafs that are found at the typical, rather boring garden centers.

Acer shirasawanum 'Yellow Canary'

While the grafters are occupied with the larger numbers, the scion cutter uses that opportunity to forage for the newer and sometimes solo trees where every possible stick is cut. Acer shirasawanum 'Yellow Canary' is an example, where the scions were firm and ready and I decided to harvest all possible, even the thin and short and fat single-nodes. One visit – all or nothing. It's like a hummingbird, with its highly-evolved brain that is more fantastic than human's I think. The high-strung little darters can remember every flower that they visit for a 6-8 hour period, because once drained of nectar it takes a half day to refill and they can't expend any unnecessary energy hovering, searching in vain. I would not be coming back to the scion-well of 'Yellow Canary' either.

Acer palmatum 'Summer Gold'

We take a different approach for a cultivar like Acer palmatum 'Summer Gold', where our stock plants are all over the nursery in sizes ranging from one-gallon pots to large 15' trees. In July, towards the end of the month, we might cut just 200 and we'll save more for August, then more in September. One constant worry is if the wood on 'Summer Gold' is sufficiently hard, so we don't risk cutting all of them early. Following the results requires attention, so for example if the percent “take” in July is only 70%, but 95% in September, and if that pattern repeats itself for a couple of years (as the seasons are all different) you might be able to draw a useful conclusion. Of course, there are other variables too, like who harvested the scions and who grafted them. Sometimes scions vary depending on where they came from, where a tree in the ground hardens quicker than those in a greenhouse container. Yes, the nursery owner carries a myriad of worries throughout the season, but after a long career where I have cut every scion for the majority of those years, I developed a gut feeling about what to cut and when. But trying to explain your “gut” to a new scion cutter is not so easy.

Acer palmatum 'Chika'

We're receiving a fair amount of scionwood harvested by MrMaple now. The leaves have been removed so we're not positive how the shoot looked like when it was still on the tree. Some of their sticks make just one scion, but others might produce three or four. The scion cutters back in North Carolina don't have any experience with summer grafting, or what an ideal scion even looks like. Hopefully we'll be pleasantly surprised with the outcome, and then everyone at Buchholz Nursery will be relieved when I'm less fussy. Our most experienced grafter (David) is the only employee handling the MrMaple scions, and that simplicity removes yet another possible variable when evaluating the outcome.

Acer shirasawanum 'Magic Moon'

Acer palmatum 'Purple Curl'

I was intrigued to receive two small plants of Acer shirasawanum 'Magic Moon' last autumn from the MrMaple owners, but I confess that I had never heard of it before. There are already a few “moon” cultivars in the trade, such as 'Autumn Moon' and 'Moonrise', so I wondered what would be so “magical” about the new MrMaple introduction. In any case, I cut 43 less than ideal scions from the two plants, and then – surprisingly – another 100 arrived via one-day transport a week later from MrMaple. The only information available, since it's still a very new introduction, was provided by the MrM bosses who introduced it a short time ago. They posted a YouTube video that displays a subtle variegation with the green mid-leaf a normal green but edged with pale yellow. Furthermore the lobes curl downward, claw-like, that is reminiscent of the Buchholz introduction of Acer palmatum 'Purple Curl'. It makes me wonder if 'Purple Curl' contains some A. shirasawanum blood as well. Such green/pale yellow coloration can sometimes appear on Acer shirasawanum 'Mr. Sun', at least when grown in containers, especially after temperatures reach the century mark. I don't particularly care for the two-toned look as I find it rather chloratic. Anyway I'd like to ground a 'Magic Moon' this autumn, but I'll be sure to place it with some afternoon shade. The original seedling was raised by Johnathon Savelich, the same grower who discovered and introduced the very popular Acer palmatum 'Lileeanne's Jewel'. You can check out the MrMaple 'Magic Moon' video HERE, but finish this more-important blog first.

Acer fabri

Acer wuyuanense

MrMaple's scion box contained a new species for me, Acer wuyuanense – which comes from China's Wuyuan County in Jiangxi Province. It is commonly referred to as the “Chocolate maple” due to its reddish-brown spring growth. I'd like to compare it side by side with a similar species, Acer fabri, which I used to grow twenty years ago. The A. fabri was in a container in our tallest greenhouse, but I decided to part with it when it kept pushing into the poly top. We used to root A. fabri but sales were weak because it was presumed to be non-hardy for most of our customers. Researching the Wuyuan species, I was shocked to find that it is growing outside at the Dawes Arboretum in Ohio, who would have thought? I don't know if the Dawes specimen is of seedling origin or if it is growing on borrowed rootstock, but they list it as hardy to USDA zone 6 (-10 F). A. wuyuanense, fortunately, can be propagated by grafting onto Acer palmatum, although that seems a curious combination, but then we have also used A. palmatum as rootstock for grafting Acer laevigatum 'Hong Long' which I discussed in last week's blog. The problem with these Chinese species is that they grow with reckless abandon in our greenhouses, and can easily produce 3-5' shoots. The A. wuyuanense species may be hardy to USDA zone 6, but the pushed, too-lush branches would have a difficult time in a typical Oregon winter. I recommend hardening it the year before planting by keeping it in a smaller pot with reduced watering the summer before. A. wuyuanense is not listed in the DeBeaulieu An Illustrated Guide to Maples, so perhaps he considers it a variety or subspecies of something else. It is also growing at the US National Arboretum in Washington D.C. and at the David C. Lam Asian Garden in Vancouver, B.C., with the synonym of Acer pubinerve. Canadian botanist Douglas Justice praises the species, by whatever name, and describes the emerging foliage, memorably, as being like “oily, dark-brown chicken feet.”

Acer erianthum

Another Chinese species, Acer erianthum, also made it back to the collection thanks to MrMaple. I grew it 20 years previous but tossed it from the ark after my one garden specimen developed “split-bark” from the sudden transformation from a week of warm March weather...to a bone-chilling mid-teen blast. Damn you nature! Why do you spoil my fun? It was planted near the species tree of Acer oliverianum which succumbed to the same freeze that I documented in last week's blog. I considered myself one-and-done with the two Chinese species, but I'm actually pleased to try them again, especially since MrMaple now pays the bills. The parent company publicizes that they want to collect all species within the Palmata Section, and it's possible that they may have already accomplished their goal. As with Acers laevigatum*, fabri*, wuyuanense* and oliverianum*, A. erianthum* can also be propagated onto Acer palmatum rootstock. The erianthum species was discovered by EH Wilson in 1901 on the same China expedition that yielded Acer griseum*, Acer fabri and Davidia involucrata, and much more.

*The specific epithets of these Chinese species are as follows:

• A. laevigatum, from Latin laevigatus for “smooth” or “polished,” referring to the leaves.

• A. fabri, honors the Rev. Father Ernest Faber who discovered the species in 1887, before Wilson “introduced” it.

• A. wuyuanense, after Wuyuan county in China.

• A. oliverianum, after English botanist Daniel Oliver.

• A. erianthum, from Latin erianthus for having wool-covered flowers.

• A .griseum, for Latin griseus referring to the grey-colored down on new leaves.

Acer palmatum 'Martha's Ghost'

Acer palmatum 'Fairy Hair'

All of the above species are relatively obscure – with the exception of Acer griseum, but again Buchholz Nursery now has new owners and I'm pleased to reacquaint myself with some of my “lost” trees as well as entirely new species. But let's now discuss some of the new Acer palmatum cultivars that the self-proclaimed “Maple Mafia” sent to us a week ago. The acquisitions came in the form of scionwood, so from an accurate point of view they don't really “exist” here until the grafts succeed and they leaf out next spring. Nevertheless they are added to our Master Plant List (MPL), our bible of all plants here with the correct nomenclature or plant spelling, which is frequently different from what the sender lists it under. An example is that MrMaple wanted to reunite Buchholz Nursery with one of the original “Ghosts,” 'Martha's Ghost' which I abandoned twenty years ago because I thought all the other Ghosts were superior. Actually I'm happy to have it back, but it was originally christened as 'Martha's Ghost', not the 'Martha Ghost' of MrMaple. Similarly the name of our Acer palmatum 'Fairyhair' was ronged by Peter Gregory and Timber Press in their Japanese Maple publication as 'Fairy Hair' – two capitalized words – but since their new edition was already in print, I changed my name to theirs to avoid confusion. As you can see: I'm German = I'm pedantic, often excessively so, but not always.

Acer palmatum 'Red Jaguar'

Last autumn MrMaple sent a few pots of Acer palmatum 'Red Jaguar', truly a vigorous grower, but there was nothing obvious about why it was selected and given an intriguing name. This past spring, about a month after it leafed out in the greenhouse, I began to see the variegation develop. I borrowed a photo (above) from MrMaple, and some of my own that proves the point, and they describe: “'Red Jaguar' is a gorgeous Japanese maple that leafs out red. Once the red color begins to fade to green, a spiderweb-like white variegation comes across the foliage. The new growth during the summer can often be red with pink and white...'Red Jaguar' was found by our good friend, Jason Stevens.” Web-like is how I would also describe MrMaple's network of “good friends” who are always bringing to the North Carolina hub new selections to try. There are a lot of maple collectors, as well as a growing number of commercial growers, who have contracted the “Maple Fever” malady over the past few years, and are causing an explosion of new cultivars on the market. This rousing activity is fueled by the MrMaple media presence which features new, interesting content daily. While the late maple author J.D. Vertrees is probably cursing from his grave, I suppose the market will eventually decide which will continue in commerce. The other day I googled the maple “red panther” to see if I could find more information or photos about it but all I got was red feline fantasy stuff. Wait, wait a minute – it's Acer palmatum 'Red Cheetah'? No, not cheetah, it's 'Red Jaguar'. Who can keep straight all of the red cat possibilities? And, for God's sake: no more Dragons either in the pantheon, there's way too many already.

Orders from High Command are clear: develop the new cultivars as quickly as possible and leave the 'Bloodgoods' and 'Tamuke yamas' to others. The common are great selections as well, but they can be bought in as liners from others if needed. The following photos are just a few of the new maples in the pipeline from Buchholz Nursery and MrMaple.