Summer Maple Propagation, Part 2

Subsequent to the posting of this blog, MrMaple corrects us as to the lineage of one of the newer Acer oliverianum hybrids mentioned below:

"The old code name of 'Nakahara beni B' is 'Hot Tamale', not 'Hot Chicken' [as I reported]. 'Hot Chicken' was a seedling we [MrMaple] collected at World Maple Park [Masayoshi Yano's home in Japan] from the parent tree of 'Hot Tamale' and 'Hot Sauce'."

I regret the error. My excuse is that it's not easy to keep straight these possibly incestuous relationships, and its likely that the maples themselves have lost track with whom they cavorted.

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Last week's Flora Wonder Blog – Grafting Days Are Here Again – was a preamble-ramble of various thoughts about the very consequential summer grafting program at Buchholz Nursery. I don't know if I pleased anyone; perhaps it was too detailed for many simple plant lovers, but maybe it was found lacking for those who hoped to gain greater propagating insights. My herky-jerky narrative actually reflects my relationship with horticulture, that I'm a servant to it and its constant surprises and challenges, as much as I am in firm control of it.

Acer palmatum 'Hubbs Red Willow'

Acer palmatum 'Hubbs Red Willow'

Now, early August, let's take a look at some Stars of the Show, the cultivars that will serve the MrMaple owners and their mail-order business, as well as providing future specimen trees for the long-established Buchholz Nursery. We always begin with species and cultivars compatible with Acer palmatum as rootstock, whether it be Acers palmatum, japonicum, shirasawanum, oliverianum or various hybrids of the above. The idea is to get the ball rolling with the straight and easy scions – plus those most early to ripen – and for the past few years the first on the list is Acer palmatum 'Hubbs Red Willow'. We are blessed with one tree in particular, a 12' tall by 12' wide specimen in our Long Road section that virtually throbs with quality scionwood. The purple new-growth candlesticks rise to 10” to 20”, perfect for three nodal sections with stems the best size for grafting. It is a very “commercial” cultivar, pretty much on the Mt. Rushmore of maples.

Acer palmatum 'Hubbs Red Willow Long Road specimen

Acer palmatum 'Hubbs Red Willow' would have been better served without the “Hubbs” part to the name. Simply “Red Willow” is apt and adequately descriptive by itself, just as Acer palmatum 'Twombly's Red Sentinel' would be a better horticultural name without the “Twombly” prefix which only clutters the name. Similarly, Acer palmatum 'Peve Starfish' – the “Starfish” part which I coined – would be better named without the “Peve” moniker which precumbers all of Dutchman Piet Vergeldt's introductions. 'Starfish' alone wouldn't suffice, if I was to decide, but something like 'Purple Starfish' would have been tremendous. But back to 'Hubbs Red Willow', the Vertrees/Gregory Japanese Maples (4^th edition, 2009) lists it under the section for cultivars “not yet assessed,” but the brief description contains a number of errors such as the incorrect name of “Hupp's” for what should be “Hubbs,” plus there's no apostrophe “s” to the name as it was named after Elwood Hubbs from New Jersey. Perhaps it was named and introduced by the Red Maple Nursery in 1992 as V/G suggests, and the confusion might have arisen due to author Peter Gregory's notoriously bad penmanship, and also the similar name Hupp's is correctly used for a very different dwarf cultivar discovered by the late Barbara Hupp of Oregon – Acer palmatum 'Hupp's Dwarf'. Anyway, hopefully I have set straight the Hubbs hubbub flub.

New employee Jordan is in training to replace me as chief scion cutter, so he harvested the 'Hubbs Red Willow' for 250 excellent, two-to-three node shoots. He was spoiled by the easy assignment, and he probably concluded that cutting scions for the other couple of hundred cultivars would be quick and simple as well. He'll learn that cutting 20-30 acceptable scions from a particular tree is more of a challenge, and time consuming than the 250 'Hubbs Red Willow', especially when dragging out a ladder is involved. And as I said before, the grafters are relentlessly nipping at the scion-cutter's heels.

Acer oliverianum 'Hot Sauce'

Acer oliverianum 'Hot Sauce'

Acer oliverianum 'Hot Sauce' is how we list the exciting new maple cultivar by the late Masayoshi Yano, although there could be some Acer palmatum in the bloodline. As I understand the story, Yano of Japan developed an Acer oliverianum seedling that he identified under the code name of 'Nakahara beni A', then gifted it to the Nichols brothers and gave his blessing for MrMaple to trade name it as 'Hot Sauce'. Acer oliverianum is a Chinese species that resides in the Palmata series, and while hardy to only USDA zone 6 (-10 F), it is quite vigorous and it withstands hot summers better than most Acer palmatums. Indeed MrMaple includes 'Hot Sauce' in their “Heatseekers Series (tm)” which they describe as “Hot! Hot! Hot! like Acer oliverianum 'Hot Blonde', Acer palmatum 'Hot Tamale' and others.” They are promoted as “Japanese maples” that thrive in full sun in the southern United States.

One, two, and three node shoots

MrMaple claims that 'Hot Sauce' is a possible hybrid with a red-leaved Acer palmatum, and they even boast that its spring foliage is “bright red turning to deep red in summer.” In our white-poly greenhouses the leaves are more greenish so I see it should be grounded – which we have done near the office – in full sun. I decided to cut 'Hot Sauce' myself since MrMaple wants as many as possible, and I have experience with relatively thin wood and short stubby wood, many of which are single-node. When I describe “single-node” I mean the section of stem with a pair of opposite buds, unlike the aforementioned 'Hubbs Red Willow' where our sections consist of two or three pairs of buds. Graft success maybe improved with the longer sticks – some say the more buds the better – but we usually get good “takes” and ample growth with the singles, plus twice as many grafts are possible.

Acer oliverianum 'Hot Blonde' autumn foliage

Acer oliverianum 'Hot Blonde' spring foliage

Acer oliverianum 'Hot Blonde'

A Heatseeker that pairs nicely with 'Hot Sauce' is Acer oliverianum 'Hot Blonde', a golden upright with an orange cast in full sun. It is a MrMaple introduction from a chance seedling from Acer oliverianum collected at the Keith Arboretum in North Carolina. The only other Japanese maple in that collection was an Acer shirasawanum 'Aureum', so that is the likely co-parent. I have grown 'Hot Blonde' for about seven years, and my original one-gallon pot soared to 15'-18' tall in the lush greenhouse. I was happy that MrMaple didn't patent 'Hot Blonde', which they considered doing, for I was propagating it five years prior to them purchasing Buchholz Nursery. The grower learns to keep his Felcos in hand, for a graft in August – even from a single-node scion – can develop into a branched, very salable one-gallon pot by the following August, with the pruners needed to form a more bushy and colorful tree. Autumn foliage is blazing red and for us it lasts much longer than most Acer palmatums. When Tim Nichols first described the cultivar and its name, I expressed a little concern that some might find it offensive, that “hot blonde” was possibly a demeaning stereotype. Personally I'm crude and sexist enough that I like the catchy name, but in Oregon the powers that be are crabby women communists that run the government, schools etc. and you had better keep your pronouns in order. Tim dismissed my warning because it was named for brother Matt's wife who very much is a hot blonde, and “she was fine with it.” I enjoy the tree and its name thoroughly, a great maple.

Acer oliverianum 'Hot Chicken'

I explained earlier that Acer oliverianum 'Hot Sauce' was a renaming of the code ID that Masayoshi Yano used for 'Nakahara beni A', and was done with his permission. Likewise, another Hottie from Yano, 'Nakahara beni B', was given the trade name 'Hot Chicken'. The name is silly but fun, but I don't have enough familiarity with it to pass judgement on its garden potential. So far we have three 5' pots in the white poly greenhouse, and like all the other A. oliverianum cultivars, it grows with enormous exuberance. We have already grafted a fair number, with all scions rush-mailed from MrMaple; but since I don't have sufficient personal experience, I'll borrow the following from MrMaple's website: "A rare Japanese selection of a heat tolerant Chinese maple that leafs out olive green to electric red…Mid-summer flushes of new growth are a bright red, making a great contrast with the older growth. 'Hot Chicken' will dazzle you with bright reds to olive green leaves…sure to make a splash in your garden." Well, the Nichols boys certainly exude enthusiasm, but we'll see if the "hot chicken" can cross the road from obscurity to a welcome standard in American landscapes.

Acer oliverianum

Acer oliverianum

Ok, MrMaple is promoting their Heatseekers for justifiable reasons, while I look at the prospects from a competitive, commercial perspective, but since I'm an Oregon nurseryman – who has certainly experienced and survived fantastic records of the Hots – I can't completely relate to the Southern Summer Experience, so I must reserve judgement. I collected the Acer oliverianum species forty years ago, a seedling gifted to me by an amateur grower with the wonderful name of Noble Bashor. I propagated for a few years by grafting onto Acer palmatum rootstock, and the offspring grew well, but sales were weak for the unknown Chinese species. My first specimen was planted at the entrance to the nursery, but it suffered from a damaged trunk during a vicious Arctic Blast, and it was edited from the landscape, goodbye, so long, farewell. I'm excited to retry the species with MrMaple's new cultivars, but we'll have to prune and winter protect with extra attention.

Acer laevigatum 'Hong Long'

Acer laevigatum 'Hong Long'

Acer laevigatum is a Chinese species that is rare in tree collections because of its perception of being non cold hardy. Specialist arboreta in mild climates can succeed with it, and since seedlings from the wild can vary in hardiness and ornamental appeal, I was happy to receive a start of one recently collected seedling from Mark Weathington of the J.C. Raulston Arboretum in Raleigh, North Carolina. It was given the trade name of 'Hong Long' – which translates to "Red Dragon" due to its purple-red new growth and black-purple stem color on the new shoots. In Oregon the so-called "evergreen" species is semi-deciduous to fully deciduous, depending on the winter. 'Hong Long' enjoys the heat and humidity of our greenhouse environment, but the problem is that its three-to-five feet of growth per year can cause the water shoots to melt to mush if we get a hard freeze. When we eventually plant one into the garden (this fall) we'll prune all the new growth back to the older branches. Most visitors cannot identify the genus as Acer when they first encounter 'Hong Long', and they frequently comment, "It sure doesn't look like a maple." I agree, it doesn't, but then many Asian species can look more like laurels or rhododendrons; surprisingly it is graft-compatible with Acer palmatum rootstock. We have rooted it with soft-wood cuttings under mist, and while the rooting percentage is usually high, I suppose those cutting grown would result in even less hardiness.

The original Acer palmatum 'Yellow Threads'

Acer palmatum 'Yellow Threads'

Acer palmatum 'Yellow Threads' is a fun, newer introduction (germinated in about 2005) that originated, not surprisingly, from the parent tree of A.p. 'Koto no ito'. It prospers in full sun in Oregon where new, spring growth emerges a light yellow-green, but when the summer heat arrives the narrow lobes transform to a bright white-yellow, hence the cultivar name. When grown in containers in the relative shade of our white poly greenhouses, the foliage remains yellow-green and belies the cultivar name. In autumn the foliage fires to an orange-red, usually, but I remember one year when it turned to straw-yellow.

Acer palmatum 'Yellow Threads'

The grafting tents

Our summer grafts are sealed in a thin (2 mil) poly tent, left to incubate for a couple of weeks. Graft takes seem to improve with the extra humidity, but the warm sweaty environment ends when new growth emerges. We then lift the mini tents for more air circulation to prevent disease on the tender leaves. At this date, exactly three weeks after the grafts were executed, only about one-half have broken bud. Many others never do until the following spring, but at first the grafter must wonder if he'll only get a miserable, 50% take. However, the following April is exciting when the overall success is 90-95%. In other words, it doesn't seem to matter if the scions break this summer or not, and the amount of new growth is the same in either case. And, of course, our later grafts at the end of September will have no scions leafing out, and those grafts too will catch up with the mid-July grafts. Hopefully I'll be around to document my claims next April which will more clearly explain the situation.

Last week's Flora Wonder Blog – Grafting Days Are Here Again  – was summer maple propagation, part 1, while today's is part 2. Next week I'll continue with part 3. It's an interesting process, and each cultivar has its own unique story…on and on for about 500 different cultivars.