“I don’t know why my Hydrangeas don’t flower” is one of the great conundrums that are handed to me by clients. As with all things, I never know exactly, nor do I have an clear answer, I can only offer that coming to understand these things takes place in the process of experiencing and working with the garden. This question almost always comes while looking upon a Bigleaf Hydrangea (Hydrangea macrophylla). Immediately one asks how it may have been pruned, the gardens history and care, considers the soil, and how cold it was the past winter knowing that Hydrangea macrophylla often experiences tip dieback where you loose the flower buds to the winter’s cold. 

A week or two ago I ordered Michael Dirr’s latest edition of “Hydrangeas for American Gardens” (2020) to begin a little study on Hydrangea. I am finding them becoming so popular, even in my own preferences, that some study is a worthwhile investment. At least at the start of this, it was Hydrangea paniculata and its cultivars that I am most interested in.

However, a little tidbit caught me while reviewing Dirr's work on Hydrangea:
Bailey (1989a) provides climatic data for the native habitats that explain Hydrangea macrophylla sensitivity to certain extremes. Honshu enjoys more than 5 months of frost free temperatures. The mean low and high temperatures are 31 and 47 degrees F in January and 72 and 85 F in August, respectively…The conclusions are obvious: H. Macrophylla prefers moderate temperatures…(73).

Most of Dirr's writing on macrophylla is based on studies done at his University in Athens, Georgia and from research done in North Carolina. Even at those southern locations, some of the named cultivars he writes of as not surviving the cold are names I recognize as macrophylla cultivars in WNY nurseries. From this I leapt to: “All these Hydrangea I see that don’t flower - they probably just aren’t hardy enough to begin with.” So. I thought I would do a little research on the cultivars most readily available to me right now and find what research I could on hardiness data.
One key is understanding the “remontants” or re-bloomers. These bloom multiple times because they will bloom on this seasons new wood as well as older wood. A hydrangea that doesn’t bloom on new wood is dependent on old wood to over winter for its flower buds. When they are killed off by frost, no flowers. But with re-bloomers, the old wood can die back to the ground but still produce flowers that season on its new wood.  I believe most traditionally we think of Hydrangea macrophylla as a plant that "blooms on old wood." 


The Study:
Generally, and this is new to me, it seems that plant breeders characterize Hydrangea macrophylla as “undependable.” Thus my curiosity of "why is this such a commonly used plant in WNY?"
To disclose, this isn't the deepest research. A few hours. I made the best sense of things reading a couple blogs, Dirr's latest edition of "Manual of Woody Plants," Dirr's latest on Hydrangea's, and a few wholesale catalogs and nurseries I have here in the office. Here is what I have found on the cultivars:

1. ‘All Summer Beauty’ - Supposedly a rebloomer but noted as inconsistent in its reblooming by Dirr
2. City Line Series. ‘Berlin Cityline,’ ‘Venice Cityline,’ ‘Vienna Cityline,’ ‘Paris Cityline:’ German bread trademarked series. Dirr observes as being heavily covered in mildew in late summer and fall:  writes “I have immense doubts about their hardiness.”
3. Teller Series. Swiss breed. Dirr notes ‘Teller White’ being sensitive to late spring frosts in his Georgia garden. ‘Teller Blue’ - seen locally as ‘Blaumeise’ - is considered the hardiest of the series. Dirr writes, “Most Tellers are not very cold hardy.”
4. ‘Lady in Red.’ Dirr’s 2009 Manual describes this as having “superior cold hardiness,” which at this point, I think means, you are probably going to lose a lot of flower buds to frost and cold in the WNY area. But. I might like to give this a try. (For some reason I feel I saw it referenced as being ideal for container planting - which is how I will try it)
5. ‘Mystical Opal.’ Of the trademarked Mystical Series. Dirr writes of these as “bred for the florist trade,” and their use as pot plants - which I take to mean, these are the ones you see in the super market in one gallon containers. Does not appear that they rebloom. I don’t get the impression these are intended to be a landscape plant. However. I do see them in nursery catalogs.
6. ‘Pink Beauty’ also referred to as ‘Preziosa.” Each nursery I reference lists ‘Pink Beauty’ as a macrophylla however Dirr (2009) lists as as a synonym for ‘Preziosa’ which is actually a hybrid H. macrophylla x H. serrata. The species serrata seems to be getting a good amount of attention the past two decades because of its potential for cold hardiness as its native habitat is in colder, higher elevations.  This doesn’t necessarily translate to ‘Pink Beauty’ being hardier, but maybe.
7. ‘Tokyo Delight.’ This is listed as a macrophylla out of an Ohio nursery but Dirr lists this (2009) as a straight cultivar of serrata. 
8. ‘Nikko Blue. Dirr writes “May be somewhat of a rebloomer.” 
9. ‘Endless Summer’ and ‘Twist-n-Shout.’ First of the repeat bloomers, however, plantain Tim Wood writes of them as still lacking as flowers on new wood don’t bloom until very late in season. 
10. ‘Bloomstruck Endless’ is one of the most recently released cultivars. Cross of “Endless Summer,” which brought the first reality of a repeat bloomer to the market. My study on this seems to record the recent history of plant breeding. 2004 was the year ‘Endless Summer’ was introduced. This has since been improved with ‘Bloomstruck’ series of cultivars which I believe were released in 2014.

What I generally find in the literature combined with my experience is that Hydrangea macrophylla's flower buds, those on old wood, are most often probably killed off. A Hydrangea can be listed as cold hardy zone 4 (for example) but this just means the plant survives, it doesn't mean the flower buds survive. It seems that even all the new rebloomers and remontants, while exciting in concept, they generally seem to be written of as disappointing - however the most recent 'Bloomstruck' series appears to be the best yet and worth my experimentation. 
The thing with a rebloomer is, it becomes a plant that blooms on this season's wood, and thus later in the season, which means a shorter flowering season. It seems the recent improvements in Hydrangea arborescens are perhaps more worth exploring.

​Just some notes.   

Post Script. April 6th, 2021.

I have been watching the Hydrangea this spring. I can see that possibly the buds on the tips get through the winter as they have the opportunity to acclimate to the deep cold of winter. But now, the beds are starting to swell at the end of March, beginning of April. The inevitability of a hard frost here in early April - well - these swelling buds are probably most susceptible to frost/cold damage now. More so now than the first week of February. 

Some notes and bullets.

1. I was thinking about writing this morning. "Writing," not really as "I wrote an essay today," but writing as something one may do all the time, a part of one's process, taking notes, leaves of paper and notebooks, saving a thought for later, posting reminders. I have this "problem" - again, not "problem" to say "a bad issue with something" but "something I am working to solve" - all of the above mentioned items, scraps of paper, notebooks, folders, design notes, post its, etc - they end up scattered about, without connection. But all these pieces floating about are what I am working on here. 
2. I have a note I put up on the board - another mechanism to try and bind things together into wholes - that reads "Give the work form." I think I have heard writers or artists say this. To me it is a saying to recognize that the space of ideas, dreams, inspiration, and creation aren't material and that you have to make something - be it poetry, sculpture, drawing, or sound - so it can find its way into the real world. Give it form.
3. I have spent a lot of time in the past, mostly in the old days when I was in school, with people who wrote many exceptional essays. All of these people, who I was thinking of this morning, could sit down and write wonderful stories and accountings of everyday life. But I could only think of one person, my friend Allen, who, like me (or me like him), collected fragments and scraps..
4. This trajectory on writing started with yesterday's notes that collected on my kitchen table following a Zoom seminar I participated in titled, "Trends in Horticulture." I captured another thought or two this morning as I had coffee and wrote them on the same sheet of paper. 
5. During this seminar, I shook my head a lot. The speaker was someone my dad's age or a little older. His points on "trends" were about edibles, organics, native plants, naturalistic gardening, prairie and meadow gardens - and after a few hours of thinking about it I came to word this issue as - he was confusing a long term social movement he was inside of with a different social thing, a trend. 
6. Edibles, organics, natives, nature... these are all ideological positions one can occupy in their practice. There is a belief system that accompanies them. 
7. The movements listed above are not short term things. These have been growing, to the point of being mainstream, for thirty years. (While at the same time we can find many of their roots back in the arts and crafts movement)
8. Part of my irk over this has to do with the seemingly unrecognized conservative or right wing aesthetic of the local industry. We see this in what follows. I try to map this with neutral description. Please accept my short comings with it. 
9. When "nature" and "the natural" are talked about in the industry, the market, and literature, the words point to different emotions - the linguistic term "registers" might be used here - and someone in one aesthetic/emotional/ideological construct can project themselves into a position of power by using and occupying tender words to point towards their (the speaker) harder forms of making the world. 
10. On the "The Left," we might say you have environmentalists and "tree huggers" - who may express concerns over "The Bee Problem" with a flavor of guilt that we, as a civilization, are doing something wrong and bad, and need to stop out of ethical consideration over the value of the bees life. On the right, the concern over "the bee problem" may be equally intense. On the right one may find the valuable position of "The Conservationist" who will most everyday wake up in alliance with the "Environmentalist." The conservationist tends to have their position based in the protection of nature, protecting the bees as an important resource to everything we humans find important. We need the bees to pollinate the the fruit trees and the flowers we love, to keep everything in nature natural so it can be experienced and visited as something we value in life. These two positions are ideological opposites. (these are just rough sketches)
11. There is of course the basic opposition: One position sees humans in a struggle opposed to nature. Another opposite position sees humans as nature and inseperably assembled to it.
12. We also see an ideological division when "the landscape" is talked about as nature. On the right, it is imagined that when we make landscapes and gardens we "bring nature to the city." The left perspective - which is a very small minority of the everyday world I inhabit - sees "the landscape" and "the garden" as something man made, just as material as brick or glass in the city. 
13. From this point, we see a different relationship between how some speak of gardening and landscape as "art." I am not sure how to imagine oppositional positions here, but I imagine one opposition being "architecture and the landscape as part of art history." It is a monument of human culture. How we make the landscape today is in dialogue with all the landscapes and ideas of the past. This may include conversations about nature. Opposite to this, I think there are a lot of different separate positions. One word, so cliche in garden writing, "Whimsey" comes to mind. Or, maybe the way to think about the opposite of a landscape that is in dialogue with cultural history is a landscape that is in dialogue with the immediate moment. 
14. In some research on Hydrangeas yesterday, I was reading Michael Dirr's 2020 revision of "Hydrangas for American Gardens." I won't try to articulate this difference  as left or right, but it is definitely a different form of imagining. Dirr works back and forth from a number of "positions" - positions I will call "botanical science," "gardener," "commerce." On the one hand you will read pages and pages of dialogue about the history of different botanists attempting (the impossibility of) to classify, with specific name, all the different repeatable observed characteristics of thousands of Hydrangea around the world. And then in his next paragraph Dirr will write "occasionally nurseries will use the name..." to recognize the separation of the pure botanical sciences from commerce. The nurseries and agriculture, while full of their own knowledges as well, are not "University Science."
15. Dirr's work is beautiful to me. It helps inform my own work. But the thinking and work that happens in the Buffalo Horticulture Project is different and has its own specific expertise. Buff Hort works with the built environment; Buffalo Horticulture deals with commerce, and studies plants and construction as commodity forms and art in history. My study in horticulture (among other things) is of plants that are in cultivation and available as materials for us to build the landscape with.

March 1st. We are probably three to four weeks away from Lesser Celandine's emergence. Going back through my photo albums from the past several years, it seems to emerge at the end of March, beginning of April, depending on the weather.

Lesser Celandine is one of the first weeds to emerge that we need to attack. A Spring ephemeral, meaning, the plant emerges in mid March, flowers in April, and is gone, dies back, by early June. I think what happens with Lesser Celandine, what allows it to colonize and take over so much space so quickly in the landscape and garden, is that it emerges before people are actively tending to the garden and landscape. When it does emerge, it's not unsightly, and has attractive foliage and flowers. “Oh. Buttercups!” How can you feel threatened by buttercups? Left alone, the Lesser Celandine goes through a couple seasonal cycles, occupying more and more space, spreading through seed and root bulblets, and then runs clear across and entire garden. You can’t spray it because it is often nested right in close with your precious ornamentals. It gets out of hand quick. 

Control. If its in the lawn, you can probably attack small outbreaks with manual digging. Most likely solution is spot treating with broadleaf weed control. In ornamentals, manual digging. Watch for it in late winter and early spring. Begin attacking it as soon a possible. Always dig it with a weed knife or trowel. Pull roots and soil out as the roots carry little bulblets that contribute to the plants spread. Attack, dig, and disturb every 2-3 weeks, never allowing it to get comfortable. It spreads, quickly! With larger infestations, some say you can limit its force with constant cutting back to the ground with a weed eater. 

​

1. The lawn hasn't grown up as a raw obsession America has with its lawns as the story may often be told. The desire for the lawn doesn’t come first. The lawn starts in a development practice where we clear the land, level it, grade it, drain it, build roads and urban infrastructure, build homes, and then put the soil back in place. That soil can’t be left bare. All soil, as part of the finishing of development, must be covered in turfgrass, both for cleanliness and to prevent the erosion of soil. If the soil was allowed to erode away, it would quickly clog up all the constructed storm water infrastructure and alter the local waterways with sedimentation. Point being, the monsters of American culture aren’t out there fetishizing lawns so much that paradise is being paved over for it alone. Lawns, in their original production and construction, are about inexpensive and effective land development.

2. Andrew Jackson Downing followed by Olmstead in the mid to late 1800s advocated for open spaces, as if each suburban home was set in a communally maintained park of which individual homeowners tended their own piece. But by the time Levittown (recognized as the first mass-produced suburb, a planned community for veterans returning home from WWII)  was conceptualized and developed in the late-1940s, the imagination of the lawn was no longer a socialist dream of the romantic American landscape. By this time the lawn’s utopianisms we reduced to the dreams of developers putting out inexpensive housing and developments suited for the automobile.

3. The development history today's homeowners are a part of is outside their agency. There are people who aren't obsessed with their lawns, they just want to give care to their spaces. I want people to feel good about giving care to their landscape and grounds and not have to face the shaming, labeling, and reduction that some like to place on them as if they are just mindless conformists to The American Lawn Aesthetic. A healthy lawn may surround someone's home because they care for it. Giving care to their space might be what feels good for them. 

While Boxwood, in a certain audiance, are certainly seen as worn out and overused because of how they fill the suburban niche of "evergreen plant that is deer browse resistant," I have been exploring and finding, for the first time in my career, ways I like to use them. This comes from recognizing them as a plant that tolerates the difficult dry shade gardens we are working with all the time in The City and also seeing them as a plant with an extensive tradition and history in the garden.. For the first time in several years I pulled out my "Dirr," as we call it generally; Michael Dirr's "Manual of Woody Landscape Plants," the original edition put out in 1972 I believe, which has been the standard reference on woody ornamentals ever since. I work with the 5th edition from 1998, however, because of the excitements I experienced in there today, I just ordered the latest edition, the 6th, from 2009.

Dirr - I think it somewhat funny - because of my simultaneous readings of the NYT literature lists - has a way of compiling a really interesting texts. Its a typical reference book, there are chunked together points on "culture," "hardiness," "diseases and insects," "propagation," and so forth. Every plant referenced in the book's thousand pages put together in the same form. But, you can get lost in the book reading all these tiny "other notes" and trivialities. In reading about Buxus sempervirens, he introduces his list and inventory of "cultivars" noting where the best collections are and that he finds with Boxwood "...once they are put to the shears no one can reliably separate them." He follows this, in perfectly straightforward scientific prose, "There is an American Boxwood Society, [he gives the mailing address], that "Boxophiles" should consider joining if all other societies are full." He then offers what he finds to be the most important reference book in case you are deeply concerned with Boxwood taxonomy and culture.

This isn't 1998 anymore so if you are one of these Boxophiles you just web search The Boxwood Society. Amazingly it is a real thing and on their website you can buy what they deem to be the most important books and compendiums on the Buxus genus. You'll find Boxwood Handbook: A Practical Guide to Knowing and Growing Boxwood (1995), by Lynn R. Batdorf as well as Boxwood: An Illustrated Encyclopedia by the same writer. This second book appears to be the most complete book on the topic, describing nearly 1100 species, varieties, and cultivars. It lists at $110.

Confronted with these references, I considered buying the handbook, but asked myself, with what I do, "how much do I really need to know about Boxwood?" Plus, there is also this thing about specialty horticulture books - 80% of the book is the same information as every other horticulture book. Twenty percent most likely details and maps out how we understand all the different Boxwood in the world, and then the remainder of the book is filled with "How to Prune," "Understanding and Preparing the Soil," "Planting and Pruning Techniques," which as it turns out, really aren't specific to the species and are just common rules of horticulture.

So - what did I come out of this with?

I was looking to better familiarize myself with Boxwood. My initial engagement with plants and namings aren't in the nursery anymore - this way of being in the business has for the most part disappeared - but happen with the catalog being my first contact with specific names. And so, I need to make sense of what is presented in books and catalogs and then impose these sense makings onto the distant nurseries and imagine them into the garden. My process here in this study begins trying to make sense of what is available to me "in production," "in commerce." I need to understand all these possibilities available to me from Nurseries that aren't in my backyard so that I can design with them and order them. I printed out or copied the Boxwood pages from the grower availability lists I deal with and had them in front of me as I read through Dirr.

For the most part, the Boxwood we would work with here in the Buffalo and Upstate New York area are of two different Boxwood species. Buxus microphylla is a Japanese native and the species is generally composed of varieties and cultivars that only grow to a couple, few feet tall and wide. B. sempervirens, which tend towards larger forms, some up to and beyond twenty-five feet in height, is a native of southern Europe, northern Africa, and western Asia. A good number of the cultivars in commerce are hybrids of the two, a cross between Korean variety of Boxwood and the sempervirens.

Understanding the difference between 'a variety' and 'a cultivar' is important to the taxonomic differences here. The Korean Boxwood used to hybridize with sempervirens is a variety. It is written like so: Buxus microphylla var. koreana.  A variety is a further identifiable grouping  within the species - in this case microphylla - that reproduce themselves in nature, in the wild. A variety often comes from and has its own distinct geographic range. We see the following varieties within the microphylla species: var. koreana, var. japonica, var. sinica, var. insularism. Most important to the variety is that it is found in and reproduces itself in nature, in the wild, as opposed to the 'cultivar' which exists, having its own identifiable characteristics, as a result of its cultivation by humans. A cultivar is written: Buxus sempervirens 'Rotundifolia.'

A variety if 'of the wild.' A cultivar is of the nursery, the farm, the garden.

Further note - I am following Dirr's work and writing on this. Plant nomenclature is one of those things that is argued and has ever higher and higher rules. So. To try and describe what a variety is; well, my description is one that allows us to understand Boxwood in commerce. But there is also a conversation about subspecies. To do this proper, we would need to argue about the difference between variety and subspecies and from the basic readings I've done on this - well, that's a job for another day. 

The annual series of conferences around the region and industry have moved to Zoom this year. of course. I spent some time in a session this morning called "Top Ten Disease and Insect Problems of Trees in NYS." It was presented by Dr. Beth Brantley of Bartlett Tree Research Laboratories. Some quick things that happened for me during the session:

A. So many things we do - we call them "Cultural Practices" -  are often about preventing disease and insect problems.  They are just standard practices, so standard I think I forget why we do them as the practices, while starting as "Good Plant Health Care" become art forms and aesthetics in themselves. Two things that were mentioned today were (1) pruning to maintain good air circulation in a plant (drier leaves = less disease) and (2) cleaning up fall and winter debris in the garden because many diseases and insects over winter in leaves and pine cones that have fallen from the tree. 
Basic fundamental stuff. Just. One forgets why sometimes.

B. On good resources. There are two books on tree insect and diseases that has long been the standard top resource on the subject, at least 30 years, and still none better. Warren T. Johnson and Howard H. Lyon's "Insects That Feed on Trees and Shrubs" (1976) and Wayne Sinclair and Howard Lyon's "Diseases of Trees and Shrubs" (1987). Both are 500-700 page, classical resource books, with full color photographs and full text descriptions.
In the internet age, resource books have surely heavily declined in use. But, the information one finds in Google searches - the books replacement - is very sketchy and hit or miss. Most everything is just "web content," garbage write ups from people just looking to attract hits to their webpages. They sell advertising.
Always look to the University pages. Every state has it "land grant college" that deals in horticulture, turf, and agriculture, and they all put out very accessible top quality information packaged for a number of audiences with different levels of expertise. Around here, look to Cornell University first. But also, Penn State, Ohio State, UMASS, University of Maryland, and Guelph, Ontario are universities I recognize off the top of my head that I can go to immediately and without question.
But also, don't forget about books. 

​C. "Oak Decline." I questioned this a bit, not out of doubt, but that we, as a field of tree experts, have objectified all Oaks, everywhere, as "in decline." This is the first time I have ever heard such a concept. It is one thing to say "Emerald Ash Bore is sweeping across the Northeast and killing Ash trees" but it is another to pronounce an entire genus of tree as being in a historical moment of stress and decline. Cited factors are warmer temperatures, drought, and ever more complicated site conditions relating to how we manage the land, environment, and urban development.

D. Another red flag that popped up for me was Dr. Brantley made reference to the trees we select "as we repopulate the landscape with the next generation of trees." 
I mean, in a way, certainly this is what we are doing, always. We work in the cities and the trees don't live forever. But at the same time, when she said it, it struck me as something not innocent but apocalyptic. 

Images I am thinking with today.

​ From: Walker, Sophie. "The Japanese Garden." Phaidon Press, NY, 2019.

Three things to say:

1. I take interest in "Land Art" - which we might place plant form/sculpture into the genera - as oftentimes in designing the use of land, in a landscape design, in a backyard, there is space: unneeded: outside the land manager and user's utility. Certain traditions of design make this turf grass - openness. In other ways of thinking, turf grass and lawn is wasteful. No matter our choices, the making of the land is art no matter our decisions.

2. The "Gardens Illustrated" feature refers to this work above as "Caruncho-esque" referring to Spanish landscape designer Fernando Caruncho. I enjoy studying Caruncho's work but it also frustrates me as I see many of his gardens (not all) as wasteful and unsustainable. His landscapes are monumental - there is no better word to describe them - and are of a completely different universe ideologically and economically. I imagine some of his private gardens have higher annual maintenance than all the municipal gardens of WNY and Buffalo combined.

3. At the same time, Caruncho's gardening work, unlike any other gardening work I am aware of, falls into the domain of "high art." His works are purely sculptural, at the far end of the modern gardening ideology that sees plants as mere and secular materials. He would sooner talk about Piero della Francesca or Diego Velazquez than any contemporary Landscape Architect. His creative medium and  process is in dialogue with art history, not so much gardening - although, I think it may be fair to say, he is in dialogue with garden history as much as anyone - only also,  is more drawn to "high art' than cottage forms of garden thought. 

    I think the pest and disease problems lawns may have are created by trying to get more out of the grass than it has to give us. Lawns are watered too much, over fertilized, mowed too closely, and have chemicals applied to the point of killing off all the beneficial and affiliated microbiology that acts in partner to keep the environment in ‘balance’, preventing infestations. Automation of watering and the desire to get value from one’s sprinkler system leave the plant and soil constantly wet which creates a healthier space for fungus than grass. Lawns aggressively fertilized push too much growth on the grass plants making for soft, tender foliage that is susceptible to infestations because of the lush nutrient density it creates - its like sugar candy to tiny insects. 
    Grubs are probably the most likely problem of a lawn at the opposite end of the managed spectrum. Light and balanced fertilization will reduce a lawns susceptibility to grubs but grubs are not the result of poor management - in my opinion. However, more often than not, if I come across Japanese Beetle Grubs, I take a quick scan around me and more often than not, you will find ornamental plants and trees that the adult Japanese Beetles like to feed on. Take a look around and you will find Little Leaf Lindens, Purple Leaf Sandcherry, and Roses, among others.  
    Grass does need a pound or two a year of nitrogen from fertilizer every season but Generally speaking, the fewer inputs into a lawn, the fewer problems.   
​