Friday, November 16, 2018

The Hillier Unknown

My well-worn Hillier's Manual of Trees and Shrubs (2014) has been the subject of the last two blogs. I am not a know-it-all when I present facts and trivia about the plants, for much of the information comes from my plant library and the internet, and plagiarizing from those sources complements what little I do know from my own experience. Today's blog will wrap up my Hillier obsession with the topic being some Hillier listings that I know absolutely nothing about – I've never seen or heard about these plants before, and so none of the photos are mine. This might be the worst blog ever, or maybe we'll have a little fun and learn something.

Aextoxicon punctatum

Aextoxicon – really?! – punctatum, according to Hillier, is “An unusual monospecific genus native to Chile and Argentina which taxonomists have historically found difficult to classify but now place in a family of its own (Aextoxicaceae).” It is evergreen and dioecious, with male and female flowers on separate trees, and it resembles the Elaeagnus genus and produces small, purple to black, olive-like drupes. Hillier says it was introduced by Harold Comber in the 1920's where a single plant survived unnamed in the woodland garden at Trewithen, Cornwall. Later it was “rediscovered” by Harold Hillier and Roy Lancaster in 1976. The Chilean name is Olivillo (little olive) or Palo Muerto (dead stick) according to, and they also consider the USDA zone 8 plant to be useful as an ornamental. I don't know what the generic name aextoxicon means, except that toxicon, not surprisingly, refers to toxic (poisonous) properties, so I wonder if the “ornamental little olives” are perhaps not to be eaten. But Aex, is that word scientific or Incan...or what? Studies have been conducted with this central Chilean bush – it is not rare – by the scientific nerds of South American academia in particular, where they measure “the magnitude, variability and correlation patterns of leaf and xylem vessel traits and hydraulic conductivity as it varies across soil moisture gradients...” blah, blah, blah. I just wonder how it received its generic name. I conclude that I don't really want to acquire the damn thing, but I would accept it if you gave one to me.

Euryops chrysanthemoides

Euryops is in the aster family (Asteraceae) and it is an “evergreen shrub with conspicuous, yellow, daisy flowerheads.” Since they range from South Africa north to Arabia, they prefer a warm, sunny position and well-drained soil. The generic name Euryops is derived from Greek eurys for “wide” and opis meaning “eye” which refers to the large flowerheads compared to the narrow leaves. One plant in particular – E. chrysanthemoides 'Sonnenschein' – is promoted as colorful and drought tolerant, blooming nearly year-round in coastal areas. And wait a minute – I guess I have seen this plant before when we vacationed in La Jolla, California a couple of years ago. I could easily acquire one as my neighbor, Blooming Nursery, grows Euryops, but then they grow a lot of perennial stuff that I know little or nothing about.

Jamesia americana

I don't think that Jamesia americana is a rare species but I've never heard of it nor seen it, and that's embarrassing because it is the “Cliffbush” native to western North America. Discovered by Dr. Edwin James in 1820, it is a monotypic genus in the Hydrangea family (Hydrangeaceae). It is not native to my western Oregon haunt, but rather to the interior western states at 1600-3000 m altitude. Dr. James was no scholarly wimp – he was, along with two companions, the first white explorer to reach the summit of Pikes Peak (14,114') which was previously reported as unable to be climbed by Zebulon Pike and his Native American guides. I drove to the top one winter that was strangely devoid of snow, but obviously the Jamesia were not in flower then. James also discovered another 100 species new to science, including the blue columbine, Aquilegia caerulea, which would later become the state flower of Colorado.

Ballota pseudodictamnus

Ok, Ballota – what's that all about? Linnaeus named the genus in the Lamiaceae family occurring from southern Europe to north Africa. But first, the Lamiaceae is the mint family and is also known as Labiatae with over 7,000 species. If you encounter a weed with a square stalk and opposite leaves and a strong scent you have probably found a member of the mint family. Remember as a kid your grandmother would give you a hard candy – but that wasn't really a candy – and it would also cure your cough? That was horehound or Ballota pseudodictamnus, and it is an ill-smelling European herb with rugose leaves and whorls of dark purple flowers. Ballota was the ancient Greek name to the black horehound, Ballota nigra, which is native to Turkey and the Aegeans, and the specific name pseudodictamnus refers to the “False Dittany” for its resemblance to the genus Dictamnus (gas plant). Dictamnus is a Cretan origanum and possibly named after Mount Dikte. The mountain is of importance because that was where Zeus was raised in secrecy where he was nursed by nymphs on goat milk. After the fall of the Titan gods, Zeus and his brothers drew lots to divide rule of the cosmos. Zeus won the heavens, Poseidon the sea and Hades the underworld. It seems as if there was no plant in the ancient or new world that doesn't harbor a history or deep meaning, or a use.

Eriobotrya japonica

Eriobotrya japonica – that's a new name for me, an evergreen genus from the Himalaya and east Asia that's related to Photinia. When I researched I found that the botanic name is commonly known as “Loquat,” so I guess I do know the tree, except that I've never grown one. The genus name comes from Greek erion meaning “wool” and botrys for “a cluster of grapes.” I've seen the fruits for sale at specialty grocery stores so I think I will investigate further.

Gaylussacia brachycera

Gaylussacia – I've definitely never heard of that. There are some 50 species in North and South America and Hillier lists two from eastern North America, baccata and brachycera, the former known as the “Black huckleberry” and the latter the “box huckleberry.” So yes, the genus is in the Ericaceae family and closely resembles Vaccinium, and the fruits are edible. The Box huckleberry is self-sterile and is found in isolated colonies which reproduce clonally via creeping roots. One colony in Pennsylvania is estimated to be 8,000 years old which would make it the oldest woody plant east of the Rock Mountains. Not bad for an unassuming, low spreading shrub with leaves that resemble boxwood (Buxus).

Sarcandra glabra

Hillier lists Sarcandra glabra, “an evergreen shrub with oblong leaves and spikes of bright orange fruits,” native to southeast Asia. Its value is that aromatic oils can be extracted from the leaves, and the entire plant is known for anti-stress, detoxifying and blood activating properties. I could sure use some of that. I wonder if I have seen it before, though, because it also occurs in China and Japan – I'll ask my wife about it.

Piptanthus nepalensis

I don't know anything about Piptanthus, but Hillier calls the nepalensis species the “Evergreen Laburnum,” and it features bright yellow, pea-like flowers. I'm not familiar with the plant because it's not hardy for me, but I may have encountered it years ago when I trekked through the Himalayan foothills in May.


I know that there are a number of intergeneric hybrids that intrigue botanists, but whether they're worthy as garden plants is another matter. I have encountered a few as names in books but have never seen the likes of Sorbaronia (Sorbus x Aronia), Sorbocotoneaster (Sorbus x Cotoneaster) and Sorbopyrus (Sorbus x Pyrus) for real. I have both Sorbus and Aronia in the Flora Wonder Arboretum – which is not unusual – but the hybrid has never been presented to me. Hillier says, “Though not of outstanding ornamental merit, they add autumn tints to the garden and are interesting because of their unusual origin.” There you have it: A BIO plant – botanical interest only. The Sorbocotoneaster sounds more interesting because the hybrid was originally found in the pine forests with its parents in eastern Siberia. Two forms are said to occur, one which tends to the Sorbus and the other to the Cotoneaster parent. Hillier was tickled to get the plant when scions were sent from Siberia in 1958, but I never encountered it when I visited the Sir Harold Hillier Garden a decade ago, so I don't know which way their specimen tends...

Sparrmannia africana

Sparrmannia is a small genus (Malvaceae family) of 7 species of tender shrubs and trees, native to Africa and Madagascar. The genus was named for Anders Sparrman (1748-1820), an apostle of Linnaeus. Hillier says it is commonly known as “African hemp,” but it is not related to the true hemp, cannabis, and he offers this nugget about its culture: “This marvelous plant not only tolerates but appears to thrive on the cigarette-and cigar-ends and tea and coffee dregs of second class Continental cafes.” In spite of that tawdry reputation the plant gained the Royal Horticultural Society's Award of Garden Merit. Maybe of more interest is that the Sparrmannia species are known for their haptonasty, the rapid movements made by the stamens when they are touched.

OK, I don't need to continue with the plants that I, and probably we have never heard of before, but there's lots more in the Manual. It would be fun to visit an arboretum which grows only these unusual things. Afterward, perhaps we could go for lunch at a second-class Continental cafe. I'll throw my cigar butts and you toss your tea bags into the cafe duff and we'll conjure up intergeneric, and perhaps even intergalactic hybrids that will occupy the next generation of taxonomists.

Friday, November 9, 2018

Hillier's Conifers

Last week's Flora Wonder Blog, The Hillier 96, was a review or critique of the Acer palmatum cultivars listed in The Hillier Manual of Trees and Shrubs (2014). The back cover of the manual claims that the contents are “revised and fully updated,” but I suggest that it can never be fully updated and complete. I know that if my observations ever came to the attention of the authors that-be they would wave them off as a vituperative attack by an unknown American nurseryman who lives to nit-pick and argue.

I never take part in internet forums – usually because they are shallow and dumb – but I like the concept. At its most elevated I imagine a free-flowing exchange of ideas and experiences, perhaps presided over by Aristotle as he ambles down the Lyceum path. Oh well, since ol' Stots knew nothing of Japanese maples he can't add to the discussion, but imagine if he was around today and took an interest in any group of plants – though, besides philosopher, he was primarily a marine biologist, he would suffer no foolish or half-baked claims by Hillier, the RHS, me or anybody else. If anything, my critique need not be feared or waved off, for it is from my simple perspective as a propagator, grower and marketer. Though I can occasionally wax poetic about plants, the bottom-line to nursery survival is to adopt Aristotelean methods.

Chamaecyparis lawsoniana 'Blue Surprise'

Even though I may have Euro detractors I'll continue with my review of the Hillier woody plant encyclopedia and focus on the Conifer section. Surprisingly it is a small part of the manual, curiously located near the end, sandwiched between the Climbers and the Bamboos. Of the 57 pages allocated to conifers, one notices that the majority of the genera and species don't contain any cultivars, and that helps to streamline the section. On the other hand Chamaecyparis lawsoniana contains 116 cultivar listings; egad, more than the 96 for Acer palmatum! Europe in general and Britain in particular appears to love their lawsons, and as long as Phytophthora lateralis doesn't infest their plots gardeners can find all sizes, shapes and colors (er...colours). Even though the native to SW Oregon and NW California, when seed was first sent (1854) to the P. Lawson and Son's Nursery, Edinburgh, the specific name of lawsoniana stuck. It was coined, of course, by a Scottish lawyer and botanist, Andrew Dickson Murray (1812-1878). At the creation of the Oregon Exploration Society, Murray became its secretary, and thus began his interest in western North American Coniferae. It seems odd that a Scottish botanist can claim precedence in the naming of an American native, but it's all hoyle in nomenclature, so no foul. I'll concede the lawsoniana epithet, but thank God the British didn't succeed with commandeering our Sequoia gigantea (Sequoiadendron giganteum) by naming it after their naval hero, the Irishman Arthur Wellesley, The Duke of Wellington. Even Hillier doesn't let the matter completely go – after Sequoiadendron giganteum he refers to “Wellingtonia, giant redwood, Sierra redwood. The “big tree”...” C'mon, stop it and quit whining. You lost!

Chamaecyparis obtusa 'Rigid Dwarf'

Hillier lists 47 cultivars of Chamaecyparis obtusa, less than half of that for C. lawsoniana, yet the former is probably more highly-regarded as a source of sophisticated cultivated variants for the modern garden. The obtusa are “blunt-foliaged” while the lawsoniana present themselves in “sprays,” and I suppose I prefer the sculptural tightness of obtusa over the fan-sprays of lawsoniana. C. obtusa is Japanese and world-known as hinoki, from Japanese hino for “fire” and ki for “wood.” Thus you have “firestick,” which probably originated from its primal use as firewood in Japan. These days the wood of the Japanese cypress is “highly valued for its rich, invigorating citrus aroma that can increase spiritual awareness,” at least according to Young Living Company. It will help welcome guests to your foyer or living room with its clean elegant scent, create a calm meditation or yoga space with its light woodsy fragrance, or best of all, can transform your bathroom into a steamy sauna by diffusing its calming scent. I have been to Japan and I agree with all of the above. The famous Osaka castle was built from hinoki wood and the trees grown in Kiso, used for building shrines, are called go shin boku or “divine trees.”

Chamaecyparis obtusa 'Nana Lutea'

Hinoki is well represented in British horticulture, and the cultivated variants listed in Hillier vary with names in Latin, Japanese and English. For Latin, we have a lot of Nana, such as 'Nana', 'Nana Aurea', 'Nana Densa', 'Nana Gracilis', 'Nana Lutea' etc. Nana refers to “dwarf,” but it is probably of baby-talk origin, and has also been used for “grandmother.” Also in Latin, we have old-time cultivars such as 'Caespitosa', 'Flabelliformis', 'Pygmaea Aurescens', 'Lycopodioides Aurea' etc., with the latter actually coming from Japan, though the name is derived from Greek lykos for “wolf” and podion for “foot.”

Chamaecyparis obtusa 'Chirimen'

Japanese names for cultivars of Chamaecyparis obtusa include 'Chabo yadori', 'Chirimen', 'Tsatsumi' and 'Suriroya hiba', the latter which came to us from Bedgebury spelled 'Siuryuhiba.” Of the above only 'Chirimen' is currently in our production. The Japanese word “chirimen” refers to the silk crepe fabric used in kimonos, but there is also an Acer palmatum cultivar – 'Chirimen nishiki' – that features long narrow lobes with a wrinkly texture. Wrinkly also is Chirimen kabocha (Curcubita moschata), a Japanese squash with a rough textured surface, and Chirimen Hokusai, a cabbage with rumpled leaves. Back to the conifer, the dwarf hinoki, one should understand that the obtusa cultivars are highly unstable and variable. What type of cutting or scionwood is selected can affect the growth rate and shape of the desired offspring. Even then, the obtusas can be individualistic anyway, and explains why “crops” can vary. If propagated by rooted cuttings, 'Chirimen' will usually grow as a dwarf irregular upright, although with age – or any stress – it can “go to seed,” where unsightly tiny bubiles partially develop, then abort and turn brown. If grafted on Thuja occidentalis 'Smaragd', 'Chirimen' is less likely to develop this characteristic, plus will grow a little faster. Normally we prune 'Chirimen' into a dense globe where numerous fingerlings poke upward, but I also have a couple of 5' specimens that have not been sheared and they resemble the sparse branching of a Saguaro cactus.

Chamaecyparis obtusa 'Golden Fairy'

Chamaecyparis obtusa 'Butterball'

Hillier's English-named C. obtusa include 'Golden Sprite', 'Golden Fairy' and 'Rigid Dwarf', all attractive cultivars, but all difficult for the nurseryman to make a profit from. Not making the Hillier cut are the wonderful miniatures 'Green Cushion', 'Butterball' and 'Gemstone', though they have been around for awhile.

Abies koreana 'Ice Breaker'

Abies nordmanniana 'Golden Spreader'

As alluded to earlier, many of Hillier's coniferous species do not come with any cultivars, or at least not known to Hillier. For the “true firs” (Abies) there are no cultivars listed for A. bracteata, A. chensiensis, A. cilicica, A. firma and many other species. The Abies with the most cultivars, not surprisingly, is A. koreana, and that is true for the Buchholz collection as well. Even the relatively new 'Ice breaker' is included, called “A remarkable miniature cultivar with a low squat habit. The white undersides of the upturned leaves give the whole plant a silver-blue appearance.” Keep in mind that all older plants of Abies nordmanniana 'Golden Spreader', that I have seen, grow “squat” at first, then eventually assume a leader. Judging by some of the vigorous apical shoots we've seen on our stock, it is possible that most 'Ice Breaker' will also grow upward. Actually, some of these shoots are harvested and grafted, and I imagine the resultant offspring will display a growth habit somewhere between 'Ice Breaker' and the parent 'Silberlocke', and for these grafts we have used the code name 'Super Breaker', just to keep track of them.

Abies koreana 'Ice Breaker'

A. k. 'Ice Breaker' originated in Germany in 1998 from a “witches' broom” found on A. k. 'Silberlocke' according to Hillier...but I already knew that. In fact I have met a few times with the finder, a Mr. Kohout from eastern Germany. Thankfully, Hillier doesn't acknowledge the cultivar name of 'Kohout's Ice Breaker' as Mr. K. would wish because 'Ice Breaker' is a name clean and sufficient on its own, while thank you Herr K. for your remarkable discovery. A. k. 'Silberlocke' has produced a large number of little curvatures from seed, and one in particular was named 'Silver Show' and supposedly displayed even more of the silvery undersides than its parent...but I could never tell them apart. Also there have been other 'Silberlocke' witch's brooms that have been set apart – Don from Porter Howse Farms in Oregon found one – but none so far has shown the vibrancy of 'Ice Breaker', and indeed the Porter Howse find eventually died on the vine.

Pinus koraiensis 'KG'

Obama inspecting the original Pinus koraiensis 'KG'

Note Hillier's use of the term witches' broom. The gardening public might not know what that means, but most nurserymen and plantsmen do: abnormally congested growth on a portion of a tree. Horticulture is replete with cultivars originating from brooms, some include Juniperus squamata 'Blue Star', Metasequoia glyptostroboides 'Miss Grace' and Pinus koraiensis 'KG' ('Gee Broom'). In each case one broom appeared on its host tree and the nurseryman propagated from that more-dwarf wood. I've never called it a witches' broom – to me witch's broom seems more appropriate. A witch with her broom. Witches is plural of witch, so the Hillier word implies that a coven of witches was required to produce the broom, whereas I think that just one witch was sufficient.

Abies pinsapo 'Horstmann'

Abies pinsapo 'Horstmann'

At the Horstmann Nursery in Schneverdingen, Germany, a witch's broom was discovered on an Abies pinsapo 'Glauca'. According to Hillier it was originally distributed as 'Horstmann's Nana' and in America I first knew it as 'Horstmann's Dwarf'. Now we are to just name it 'Horstmann'. Ok – good. It makes a wonderful conifer for the garden, but not really for a small intimate garden or a rock garden because it can get large. My oldest is about 6' tall by 8' wide at 25 years old. Also it can grow a little wild by producing shoots up to 18” long, as if it's trying to revert back to the parent tree's size. It's an annual task that we prune these completely back to the base. Anyway, that's one of the criteria for judging a witch's broom-originating plant, namely, how likely is the plant to revert?

Cryptomeria japonica 'Sekkan'

Hillier lists a couple dozen cultivars in the Cryptomeria section and it's puzzling why some of the names end in -sugi. 'Bandai-sugi', 'Jindai-sugi', 'Rasen-sugi', 'Sekkan-sugi' and 'Tenzan-sugi' are the culprits. The -sugi is redundant since it is the Japanese word for Cryptomeria. Basically Hillier is naming a cultivar Cryptomeria japonica 'Sekkan' Cryptomeria. No dash-sugi is needed after 'Sekkan'. My experience with 'Sekkan' is that it is a superb, colorful garden plant when young. Hillier calls it a “small tree,” but not in Oregon where mine grew to over 30' tall in about 25 years. At some point the cream-yellow of youth loses its vibrancy and then it looks like a chlorotic green tree. Since it was one of the first conifers ever in my original Display Garden I allowed it to stay when it no longer looked good. Finally I gave the removal edict. My employees looked at each other, thinking the boss has really lost it because the tree was doing no harm. In its stead I planted a C. j. 'Rasen' and now I'm much happier.

Cryptomeria japonica 'Spiralis'

Also in the Display Garden is a Cryptomeria japonica 'Spiralis', and when I went through the Hillier book I was reminded that the common name is “Grannies' Ringlets.” Hillier allows that there are a couple of large specimens in Britain, “But as grown in general cultivation, it forms a small, slow-growing bush of dense, spreading habit.” My specimen is broad, but it has shot upward to over 30' tall. I don't brag about these sizes because I would rather have trees of smaller stature and I generally don't like when garden trees grow into – and ruin – each other. I've never grafted a Cryptomeria onto a Sequoiadendron, or vice versa, but boy the bark and foliage look very similar on the two genera.

Fokienia hodginsii

The Chinese conifer Fokienia is “A genus of a single species [hodginsii], related to Cupressus and Calocedrus and resembling Calocedrus macrolepis in foliage.” I used to grow it – my start coming from the Arnold Arboretum where obviously it was growing indoors. One can root Fokienia but it is probably not hardy enough to be grown outdoors in Oregon. For what it's worth, Rushforth in Conifers claims that it is hardy to USDA zone 7: “It appears to be perfectly hardy, being recorded by the Chinese as tougher than Sequoia sempervirens...” I don't know, my original start croaked the first winter after being planted out, and we didn't get below 10 degrees F that year. Before I risked it out in the garden I cut five scions and grafted them onto Thuja occidentalis 'Smaragd', hoping that the rootstock would give the top a hardiness boost. All grafts took and in short time they grew to about six feet tall. They were floppy and unattractive though, and worst of all was a very unsightly graft union. The two genera hooked together but not well, and if I remember correctly, the Fokienia became two-to-three times larger than its rootstock. I sold one with the caveat that “I don't really know what you're getting.” The customer agreed and planted it out in his southern Oregon garden...where it too died the first winter. After that report I dumped my four remaining trees never to grow it again.

Amentotaxus argotaenia

Another Chinese conifer of dubious hardiness is Amentotaxus argotaenia, an evergreen tree in the Taxaceae family. Hillier says “They are ill-adapted for all but the most sheltered gardens in the British Isles and are best grown under glass.” Well, mine are under poly in my not-much-profit hobby house. To propagate we root from hard-wood cuttings in winter, but I don't have space to keep too many of the USDA zone 8 (10 degrees F) trees around. Amentotaxus is known as the “Catkin yew,” in fact the catkins are known as aments, hence the generic name. The specific name argotaenia refers to the silvery undersides of the yew-like leaves and comes from Latin argentum, and that from Greek argyro(s) meaning “silver.” The seed is covered in a green fleshy aril, which then turns to bright red in autumn and then to purple by winter. The species is threatened due to deforestation and its slow rate of growth, plus rats find the fruits tasty and disrupt distribution.

Cuprocyparis leylandii 'Golconda'

I used to grow x Cupressocyparis leylandii cultivars at the beginning of my career, but today you can buy them cheaply at the box stores where their retail price is less than my wholesale costs. The leylandii is a hybrid between Cupressus macrocarpa and Xanthocyparis (Chamaecyparis) nootkatensis and Hillier claims it is the “fastest-growing conifer in the British Isles.” Though both parents are western North American species, the original hybrid occurred at Leighton Park in Wales in 1888 and was grown by C. J. Leyland, and since the hybrid is usually sterile, it can only be propagated vegetatively, usually by cuttings. Personally I hate the hybrid, but I allow that it can make an effective large hedge, and does so quickly, so it could be useful especially if you don't like your neighbors. As I've said before, I keep old editions of the Hillier Manual of Trees and Shrubs, so I can document when plant names change. Somewhere between the 5th edition (1981) Cupressocyparis (Dallimore) became Cuprocyparis (Farjon) in the 8th edition (2014). But I don't have an explanation for why the name was changed.

Dacrydium cupressinum

Hillier describes Dacrydium cupressinum as a member of the Podocarpaceae family, and it is an evergreen conifer native to New Zealand. The “Rimu”* or “red pine” requires a sheltered location in Britain, but it makes a “charming specimen for a conservatory.” I grew it long ago, my start coming from the Strybing Arboretum in San Francisco, where a marvelous specimen graced the outdoor collection. Hillier sites another botanist when he states, “Considered by the botanist Cheeseman to be 'as beautiful and attractive as any tree in New Zealand.'” Thomas Cheeseman (1846-1923) was born in England, but his family left for Auckland when he was six. He was best known for his publication in 1906 of The Manual of the New Zealand Flora. Anyway, I agree with his assessment of the Dacrydium. Though I kept my stock indoors it eventually grew too large and I sold my oldest tree to a California customer. The Rimu would root by hardwood cuttings in winter, but much effort was required to train one into a “tree” – more often you would have a strongly-staked branch-like specimen. Heater failure one winter ended my Rimu run, but thanks for the memories.

*Rimu is the Maori name for the tree.

Cupressus cashmeriana
Picea breweriana

It is always fun for me to go through the Hillier manual. My 2014 copy is well-worn indeed. Even if I grow a particular tree and know it well, I still am curious about the Hillier take on it. The manual is far from dry, and I love the adjectives used to describe trees, for example: remarkable, handsome, elegant, rare and beautiful, most beautiful, striking, unique, distinct, graceful, neat, etc. Cupressus cashmeriana is “One of the most graceful and beautiful of all conifers.” Picea breweriana is “Perhaps the most beautiful of all spruces...” I like these plant descriptions that come through the heart, not the microscope lens.

I've been to the Hillier Arboretum three times, and I would love to go back for another visit. I fantasize about discovering a tree there and taking a photo of it. Then old Harold Hillier would jump out from behind and explain its story. I would never want to wake from that dream.

Friday, November 2, 2018

The Hillier 96

I have called the Hillier Manual of Trees and Shrubs (2014) my plant bible and it has been a highly useful publication for me, to assist with my understanding and appreciation of woody plants. And, also of great value, by listing the various cultivars of the species it allows one to note the variations of shapes, colors and growth habits within a species.

Acer palmatum 'Red Emperor'

Take Acer palmatum cultivars, for example: Hillier lists 96, and a number of synonyms on top of that. Descriptions can be sparse, as with A. p. 'Hessei' ('Elegans Purpureum'): “Leaves bronze-crimson. C 1893.” For A. p. 'Red Emperor' ('Emperor I')* more information is provided: “An outstanding cultivar with deep purple-red foliage and crimson autumn colour. Similar to 'Bloodgood' but coming into leaf two weeks later, reducing the risk of spring frost damage, and with more translucent red autumn foliage.” Of course that might not be the case in other parts of the world where it is grown. Vertrees/Gregory in Japanese Maples (4th edition) doesn't even list 'Red Emperor'; they go instead with 'Emperor I', but suggest that “'Red Emperor', which also originates from Red Maple Nursery, fits the above description and may be the same cultivar.”

*Just in case we keep them separate.

Acer palmatum 'Shigi no hoshi'

Acer palmatum 'Tsuma gaki'

The second part of a Japanese maple name – or any Japanese plant name for that matter – should not be capitalized. In English it can be, such as with 'Crimson Queen', but not for the Japanese 'Tsuma gaki', and Hillier agrees to follow this practice. One habit that annoys me, though, is the preponderance of dashes in the names, such as 'Shojo-nomura', 'Sango-kaku', 'Koto-no-ito' etc. M. Yano in his Book for Maples manages many hundreds of Japanese maple names without ever once using a dash. Ditto with Maples of the World (1994) by the three Dutchmen: van Gelderen, de Jong and H. J. Osterdoom. So why are the English so predisposed to dash? Actually, Vertrees/Gregory employ the dash sparingly. But why 'Chirimen nishiki' (no dash), 'Beni kumo-no-su' (yes, partially) and 'Shigi-no-hoshi' (yes, completely)? Who is Mr. Dashing, the dash decider?

Acer palmatum 'Pung Kil'

Acer palmatum 'Hubbs Red Willow'

The Vertrees/Gregory maple tome (4th edition) is billed as “Revised and expanded to include over 600 plants,” but that includes some from species other than palmatum. It must be a difficult task to narrow the palmatum listings to only 96 as Hillier does when there are over a thousand to choose from...and more on the way. Many of Hillier's exist in older gardens and arboreta I suppose, especially those in Europe. 18 years ago at a Maple Society conference a Canadian botanist declared in a condescending tone that “Surely we have enough cultivars of Japanese maple.” I don't agree at all, because the gardening world doesn't really need the old 'Red Pygmy' which was selected in the Netherlands before 1969. I would leave it off my top 96, and so too 'Linearlobum Atropurpureum' C 1881, in favor of the much improved 'Pung Kil' or 'Hubbs Red Willow', both introduced within the past 18 years.

Acer palmatum 'Celebration

Acer palmatum 'Strawberry Spring'

Hillier lists A. p. 'Aka-shigitatsu-sawa', but in the Vertrees/Gregory 4th it has been changed to 'Beni shigitatsu sawa' – and without the dashes in this case. Both aka and beni mean “red” according to my Japanese wife, but beni better describes what kind of red. Vertrees calls 'Beni shigitatsu sawa' “the red-tinged form of 'Shigitatsu sawa'” and later states that “It is not as strong growing as its green counterpart.” I find the opposite to be true. Also that it is “not easy to propagate and is rather rare in nurseries and collections.” It may have been rare in 1978 with the first edition of Japanese Maples, but certainly not difficult to propagate. It is becoming “rare”  again because it has been surpassed by better variegated cultivars such as 'Purple Ghost', 'Amber Ghost', 'Celebration', 'Strawberry Spring' etc. I keep one or two 'Beni shigitatsu sawa' on the place for old time's sake, but nobody requests it anymore, at least not from me.

Acer palmatum 'Kamagata'

In Maples of the World, 'Kamagata' is called a “neat dwarf.” My original plant is now in a Virginia garden, and it is over 20 feet tall. The Vertrees [original seedling] stock plant, if still alive, is under 2 m in height at about 40 years of age. Yes, you would expect that the original seedling would not grow as large compared to my oldest being grafted onto vigorous green understock. This could be said for many cultivars, and it's why it is of no importance to describe size of the original, because everyone else will be growing something else, one grafted onto borrowed roots.

Acer palmatum 'Kamagata'

I'm not just wandering around here describing Acer palmatum cultivars, so I'll reiterate this blog's theme: that I find Hillier's 96 to contain many old-world Eurocentric cultivars that I don't think are even in the trade in England – let alone America – anymore. Really, I don't care – I just find it to be a queer listing for 2014. Even the Vertrees/Gregory publication of 2009, and especially the Dutch book of 1994 are quaintly outdated when it comes to descriptions of Acer palmatum cultivars. 'Goshiki kotohime' is described as, “It is quite difficult to propagate because of the lack of vegetative growth. Scions for grafting are extremely short, offering less than 1 cm to work with.” Nonsense – if stock is held in a greenhouse, the plant can achieve 12” of new growth, and we normally get about 85% from grafting, and average 95% by rooted cuttings.

Acer palmatum 'Ariadne'

Many of the 96 I totally approve, and Hillier lists one of my favorite cultivars, A. p. 'Ariadne', an introduction of Firma Esveld of Boskoop, The Netherlands. It was named after one of D. M. van Gelderen's granddaughters, and it is most lovely in early spring with pastel shades of orange-pink with conspicuous green veins. Sadly the coloration doesn't hold up for long. It doesn't burn, but it's just not as vibrant after the first month. It's worth growing though and I planted one close to our driveway so I could please my wife. Ariadne is a more common name in Europe than America, for she was the daughter of King Minos of Crete and his wife Pasiphae in Greek mythology. By her mother, she was the granddaughter of the sun god Helios.

Acer palmatum 'Orange Dream'

The Italian introduction of A. p. 'Orange Dream' (c 1990) should be included I think. Hillier describes it: “Large, upright shrub with green shoots. The 5-7 lobed leaves are bright orange-yellow turning yellow in autumn.” I've grown many myself, but I'd like to see it in Hillier's England because in Oregon the “orange” part of the “dream” only lasts a few weeks – a fleeting dream indeed. At least by June any orange is gone, and even my old established tree in the Display Garden burns on the canopy top by July-August. 'Orange Dream' was introduced by Gilardelli Nursery of Italy. Vertrees compares it to the somewhat similar 'Katsura', stating, “However, it has proven to be less susceptible to drought than 'Katsura', but seems more difficult to propagate.” In my experience, grafting 'Orange Dream' is more successful than 'Katsura', and also I find it to be one of the easiest of all palmatums to root from summer cuttings under mist.

Acer palmatum 'Summer Gold'

Gilardelli Nursery also introduced A. p. 'Summer Gold', which is sort of similar to 'Orange Dream' except that the former is a much better cultivar, at least in Oregon, and that is because it is less prone to sun scald. It is not included in the Hillier manual, but it is in the older-published Vertrees/Gregory book, so I would consider that a serious Hillier omission. It would certainly make my top 96, and even be in consideration for my top 10. When I was first testing 'Summer Gold' I kept the main group of 6-7 foot containerized trees in the greenhouse, except for one that spent the entire summer outside in full sun. The greenhouse group grew larger, but the outside tree did well enough, even when we reached 100 F.

Acer palmatum 'Fireglow'

One more for Gilardelli Nursery, their introduction of A. p. 'Fireglow' made Hillier's list. It is described as “A vigorous large shrub with deep red-purple foliage. Similar to, but considered an improvement on, 'Bloodgood'.” That's an odd way to put it – on, 'Bloodgood'. I would have said over 'Bloodgood'. I have never thought of 'Fireglow' as a “large shrub;” I have always considered it a “tree.” And to call it an “improvement on, 'Bloodgood',” nothing mentions in what way. In my nursery you can grow a 'Bloodgood' to 6-7 feet a year faster than 'Fireglow', so the former is more profitable for the nurseryman. I'll admit, though, that if I could have only one in my garden I would choose 'Fireglow'. The purple-red of the tops of the foliage is about the same, but the aptly named 'Fireglow' is more impressive due to the color of the undersides of the leaves with the sun as back-light. They truly do glow.

Acer palmatum 'Lutescens'

Parrotia persica 'Golden BellTower'

A. p. 'Lutescens' is in Hillier's book: “Leaves glossy green turning clear butter yellow in autumn. c 1928.” I like the cultivar but I don't grow it anymore...because no one would buy it, so it wouldn't be on my list. Also, one must be careful to describe autumn color. I grew a group of the new Parrotia persica 'Golden BellTower', a nice compact cultivar selected for golden fall color. Last year all 20 trees turned perfectly gold at one time. One was planted this spring at Flora Farm, and today the autumn color is yellow, orange and purple, same as the type. The same can occur with the maples. Some factors include water and fertilizer, container versus ground, the weather the previous summer, and probably for other reasons that I don't know.

Acer palmatum 'Beni schichihenge'

Acer palmatum 'Shojo no mai'

Of course A. p. 'Butterfly' made the list, “Raised in Japan before 1938.” It wouldn't make my list because the variegation looks “dirty” by mid-summer, and I much prefer the cleaner look of 'Shojo no mai' or 'Beni schichihenge'. 'Shojo no mai' does not make the Hillier manual but 'Beni schichihenge' does. 'Beni schichihenge' has been around since 1967, and its name means “red and changeful.” I've never seen red, only pink and orange. I once saw an 8' tree at another nursery that was in desperate need to be potted up. It was in May in California and I was stunned by the copious amount of orange in the leaves. It didn't have much for new growth – it was struggling – but the color was fantastic. Sadly I was without my camera.

Acer palmatum 'Beni komachi'

Hillier calls 'Beni komachi' – well, 'Beni-komachi' – “A medium-sized shrub with leaves very deeply divided into 5 slender, curved lobes, bright red when young, turning red-purple then greenish-red.” I don't grow it anymore because it was prone to powdery mildew and it always reverted. The reverted growth had vigorous branches with larger leaves that looked like 'Shindeshojo'. You had to catch that early and prune it off, and ultimately I considered it too high-maintenance. For unknown reason the selection's (Japan, before 1930) name means “red mirror,” and sorry, it wouldn't make my top 96.

Acer palmatum 'Corallinum'

Hillier describes A. p. 'Corallinum' as “rarely seen.” In America it is not so rare anymore, and it is one of my favorite large-dwarf cultivar due to its spring leaves. Both Hillier and Vertrees/Gregory describe them as “shrimp-pink.” I sold a wonderful specimen that was about 10' tall and 10' wide about 5 years ago because it was growing too close to the road near the office. We have had careless knucklehead truck drivers too close to it when backing up, and imagine the astonishment of  the involved insurance companies when I would put the value on it at $10,000.00. Well, go find a replacement then that is so large and nice. An interesting story is related about a specimen of 'Corallinum' – found in earlier editions of Japanese Maples – that Vertrees was admiring the tree growing in the Hillier arboretum. In Vertrees' research he mentioned to old Harold Hillier that some growers and collectors were referring to 'Corallinum' as 'Sango kaku'. Hillier snorted and replied, “Why, they're as different as cheese and chalk.”

Acer palmatum 'Tamuke yama'

Acer palmatum 'Red Dragon'

A red dissectum from New Zealand is in the top 96 – A. p. 'Crimson Princess' – but it wouldn't be in mine. Hillier refers to it as “dwarf,” but I find it to be an unattractive, sprawling shrub. Its red-purple foliage is decent, but the form is untidy compared to the dome-shaped weepers such as 'Crimson Queen', 'Red Dragon', 'Tamuke yama' and others. I might still have one or two on the place, but we have discontinued propagation in favor of the aforementioned. It entered the trade as 'Crimson Prince', but the twice-bankrupt New Zealand company was told that there was already a 'Crimson Prince' cultivar for a red upright palmatum.* So they changed the name to Princess, but today different American companies list it both ways. Actually, that was one of the goals of Vertrees' research: to straighten out the nomenclatural mess caused by careless Japanese, American and European horticulturists. Obviously it is an ongoing process because we're just as screwed up now as ever.

*Supposedly originating as a seedling from A. p. 'Bloodgood', and introduced by Princeton Nurseries in 1988. Growing to 25' tall by 25' wide, perhaps Hillier should have included 'Prince' instead of 'Princess' for the top 96.

Acer palmatum 'Ornatum'

Ten steps from my front door is an old specimen of A. p. 'Ornatum', planted by the previous owner. Like I often do, he planted it too close to the walkway and now I have to keep pruning it back. Hillier doesn't reveal much: “Leaves bronze-tinted. c 1867.” I don't dislike 'Ornatum', but I know that I could never sell it, and so it has never been propagated by Buchholz Nursery. It was an old European selection that has been known by a number of names such as 'Dissectum Ornatum', 'Ornatum Purpureum', 'Amatum', 'Spiderleaf' and others. 'Ornatum' is different and I guess deserving of cultivarhood, especially in 1867, but it wouldn't make my top 96. Probably I would rank it at 960.

Honestly I'm not miffed that there aren't any Acer palmatum cultivars of mine that are included in their 96 choices. The latest (2014) edition of The Hillier Manual of Trees and Shrubs is published by the Royal Horticultural Society. The editors, James Armitage, Dawn Edwards and Neil Lancaster, and the consultant editors John Hillier and Roy Lancaster are noted luminaries in the plant world, or at least in British horticulture. You can't blame them for not shoe-horning into the Manual a few more American or Japanese selections. They would say that the type can't get smaller, or more pages added to an already thick 567 paperback publication. If there are to be future Hillier editions it would be simple to contact the American Branch of the Maple Society and take a survey of the members' list of 96 most worthy Acer palmatum cultivars. Then gather a few cognoscenti from Europe to select what are some from the 96 that are no longer horticulturally valid. Nobody enjoys more than I the “history” that can be gleaned from the Manual, but it could be made a little more relevant to the modern gardener.

Go ahead - who cares!
Can sometimes critique
Can never critique

To critique your wife, daughter or girlfriend can be risky indeed, even if you are positive and sincere about it. The RHS has earned its exalted position, and certainly does not need to defend itself from this finger-pointing Oregonian. I once mentioned to another nurseryman that I loved and practically worshipped the Manual, but that it does contain some mistakes. “Like what?” – he demanded to know. I fired back that the discoverer of Pinus contorta 'Chief Joseph' was Doug Will – not Wills, and that Dan Luscomb, not Don Luscombe, is raising seedlings from the recently discovered Xanthocyparis vietnamensis at Bedgeberry [sic].

The back cover of The Hillier Manual of Trees and Shrubs says, “Revised and fully updated.” No, not fully, it can never be complete.

P.S. I didn't mean to cause alarm – nor was I looking for praise – when I said last week's blog might be the last. I was just coming to grips that Buchholz Nursery, The Flora Wonder Arboretum, The Flora Wonder Blog...and of course myself will eventually come to an end. But that hopefully you will continue beyond me, at least for a while more.