Read Jason Doran’s review of The Trees of North America: Michaux and Redouté’s American Masterpiece as published in The American Gardener January / February 2018 issue:
“Coinciding with its 125th anniversary this year, the New York Botanical Garden (NYBG) has released The Trees of North America: Michaux and Redouté’s American Masterpiece. This beautiful book is a reorganized, updated, and easy-to-read version of The North American Sylva, which was first published as an English translation in 1817. At the time, it was considered the preeminent authority on North American trees, and this edition promises to be equally well respected….” Continue reading …
As this Rococo acid trip of a front yard demonstrates, art is a subjective matter. Kudos to this unknown Boise eccentric. I’m awarding an “A” for enthusiasm.
The garden is a terrific place for objet trouvé - or “found art”. When a friend approached me about transforming an antique carriage tire hoop into a garden sculpture, I agreed on the condition I could set something on fire (yep, I’m still obsessed with Shou sugi ban).
A while back, a friend and I discussed the similarities between the composition of music and landscape design: things like contrast, counterpoint, melody, dissonance, and unity . And just as these elements have been mixed, remixed and reinterpreted into a multitude of musical genres, landscape design can be richly varied in style and expression and still be, in a very expansive sense, "good". The bland, "sameness" of much contemporary landscape "design" in many ways resembles what Elton John once lamented as the "sameness" of contemporary pop radio.
This might strike the reader as an odd way to introduce shou sugi ban, (the ancient Japanese technique of preserving wood through a controlled charring process), but stick with me and let me explain.
Shou sugi ban (literally "burnt cedar board") was developed in medieval Japan as a way to protect wooden buildings from fire. As anyone who's tried to relight a cold, carbonized piece of firewood knows, this is an excellent (albeit non-intuitive way) to fireproof wood.
The process also arrests decay and repels insects without the need for chemical preservatives, paints and retardants. Up until the early 2000's, this was essentially a "lost" art in Japan. Modern cladding like plastic and concrete had largely replaced this traditional construction technique. Shortly after it was revived in Japan, architects all over the world, particularly in Europe, started employing the technique.
But here's the cool part: rather than merely imitating traditional Japanese architecture, European designers integrated this technique seamlessly into contemporary design and the old was new again.
We've been incorporating shou sugi ban into our projects for a little over a year now- a technique we think dovetails perfectly with our goal of constructing beautiful, sustainable and unique landscapes for our customers. Here's a glimpse of some of what we've been working on.
We've spent most of our winter "down time" conceptualizing and constructing a garden pavilion that we hope will inspire and challenge visitors.
Check out the link below for a taste of what you'll see.
We hope to see you this weekend!
I've heard folks describe our winter as one of the mildest they've ever seen in our area. So why do so many conifers that looked so peachy back in the fall now look this?
Or like this?
A recent post by a respected local garden blogger described it as the result of bitter cold we experienced earlier this winter. Cold? Yep. It got cold (1 F°), but only briefly and well within historical averages and certainly within the tolerance of the many conifers that were damaged this winter.
So what gives?
The short answer is it's not the cold per se, but rather the whiplash nature of the weather in November. We enjoyed a late gardening season with warm weather into November, and then we were nailed by a polar vortex that dropped temperatures from a high/low of 69 F°/46 F° on November 9th, to a high/low of 22 F°/1.2 F° less than a week later!
Some plants just have a really tough time riding these kinds of rapid transitions. One of the conifers that has struggled the most in Boise is the Hinoki cypress. I bet you can pick it out in this line up.
Here's another Hinoki cypress in my own yard.
And another Hinoki cypress in my parent's landscape. Note how green the bamboo looks (what winter?).
Another interesting aspect of this "whiplash weather" is how it impacted the same kind of tree so differently. A friend and I were puzzling this morning on why the White pine on the left fared so poorly compared to his buddy on the right. Southwest exposure? Wind protection/exposure? A difference in the water holding capacity of the beds on either side of the driveway? Go on, speak up if you think you know.
Unsurprisingly, I've had numerous calls and consultation requests during the last month. My advice? First, given our warm weather, seriously consider turning on your sprinklers early this year. Desiccation is really rough on a weakened tree. Second: be patient and wait to see if the tree pushes new growth. It may be June until you can really see the extent of the permanent damage. My prediction is that most of the pines will spring back. I'm not so sure about some of the Hinoki cypress (including my own).
|I dunno, Ardith, I'm kind of thinking the old lime green chairs would have been just fine...|
January of 2014 didn't provide us with ideal landscaping weather, but we persevered, completing the patio fire feature in February
By late summer the hardscape had been in for months and the plants had really begun to fill in.
|Plant tapestry, anyone?|
And so we come full circle. Happy New Year everyone!
The folks over at the Boise Larry Miller Subaru had a problem: the two south facing areas of turf in front of their showroom looked nice enough, but demanded an obscene amount of water. Worse, over-spray from the broadcast irrigation was staining their shiny new Subarus.
As a sponsor/supporter of the Idaho Botanical Garden, naturally Larry Miller Subaru turned to IBG for turf alternative ideas. IBG horticulture director Toby Mancini, sketched up a plan that included creating berms in the two areas out of a specific soil "recipe" (25% organic compost, 25% fractured 1/4" gravel and 50% screened topsoil), especially formulated for xeric, zonally adapted plants. The plants he specified read like a list of the "who's who" list of dependable, drought tolerant and readily available specimens, perfect for the dry intermountain west. They included:
|Philadelphus lewisii 'Blizzard'|
|Panicum virgatum "Heavy Metal'|
|Nepeta racemosa 'walker's low'|
|Oennothera macrocarpa subsp. incan 'Silver Blade'®|
|Echinacea x 'Cheyenne Spirit'|
We jumped at the opportunity when Toby asked us if we be interested in the installation and were able to complete the project in a single day (including the conversion of the broadcast sprinkler system over to single source drip system for each plant*).
|Clean up after a long day.|
|Fresh installation = lots of negative space. By mid-summer next year, the plants will really start filling in.|
*I generally prefer broadcast irrigation because I believe it promotes good lateral root development as well as a vibrant soil ecology. This is a great example, however, where drip was the right way to go to eliminate wasteful over-spray as well as runoff from the berm. Our preferred approach is to loop a 1/4" line with 6" emitter intervals all around each plant, making sure that each 1/4" line is directly connected to a 1/2" feed line for even water volume throughout the bed and even distribution of water around each plant.
Corten is often associated with modern gardens abiding by rules of strict linearity and an emphasis on negative space, I was delighted to find panels of oxidized steel sprinkled throughout a woodland garden during a design consultation earlier this summer. The warm, earthen tones of the rusting panels leapt out of the shadows and contributed to a visceral feeling of movement throughout the garden. I took this as the starting point for the design of an outdoor room in a woodland garden.
A concave 8' x 9' oxidized steel panel acts as the back wall and abstract focal point "painting" for the room. An arcing, andesite stone wall, green roof arbor and steel edging all add to the feeling of an open, yet delineated space within the garden.
|A Yankee doodles.|
The vertical expression of these concentric circles (the panel, the arbor and sloping andesite wall) are all critical in defining the space.
|A completed concept. No, wait- the rocks are too much.|
The home is in a neighborhood nestled against the Boise river that provides a micro-climate achingly close to zone 7, with trace amounts of honest-to-gosh humidity and an actual water table; perfect for the dry, woodland, under-story plants we installed.
|Just another Mendelssohn/Front 242 mashup.|
|Before the intervention.|
|Construction of the andesite wall and steel panel base.|
|Kevin Knickrehm attaching the green|
roof arbor to its i-beam armature.
|I almost like it as well unplanted. Almost.|
|As I was flying by.|
|The very underutilized Buckwheat (Eriogonum).|
|Wild heuchera happily anchored in a granite outcrop.|
|Color. Texture. Form.|
|When I combined sedum & heuchera in this project, a friend remarked how odd they thought this combination was. Ha!|
|First time I've seen this wild clematis. I definitely need to find out more about this plant!|
|Yep, that's a landscaper's hand.|
|Back to Boise.|
If I was to draw a Venn diagram showing the overlap of my gardening and landscape interests, you'd probably find edible green walls smack in the center, next to medieval Japanese stonework and my fig tree.
Oh look, I did.
Up to this point I've mostly written about green walls as an ornamental element, but vertical space is also a terrific place to grow an edible garden. My long term goal for our own property is to place an edible component within three or four steps anywhere on our acre. We're lucky to have so much room, but with the continuing trend of urbanization and smaller lots, many people don't have the room to grow greens and veggies conventionally. But if you've got a wall, there's a way.
Skyfarm: Gordan Graff
Part of a larger concept called Agriculture 2.0, this discussion of urban of food production rarely takes into consideration some of the problems that need to be solved to make this vision real.
Soil based green wall systems, for example, are very heavy, requiring serious engineering for the support armature. GLTi's 2,380 square-foot living wall in Pittsburg has an estimated weight of 24 tons when fully saturated. Some have even described this kind of urban farming as financially nonsensical.*
Personally, I think it makes a lot of sense, if the design challenges can be addressed. To that end I started experimenting a few years back (successfully, I might add) with a lightweight mineral wool system.
So far, we've grown nasturtiums, chard, tomatoes and dozens of varieties of herbs including rosemary, thyme, sage, mint, basil and oregano.
This year I plan to try out collard greens, rainbow chard, spinach, rapini and cabbage.
Rest assured I'll be sharing pictures of our edible green wall through the season.
*But the author seems to have some internal conflict on the matter as demonstrated by this article.
What do I mean by that? Most of our installation projects consist of improving existing landscapes. Often this involves adjusting the scale and style of the hardscape components of the landscape (things like patios and walkways), to compliment the scale and style of the home; details that should have been considered the first time around.
I'm astonished at the amount of effort and creativity in home design that promptly stops at the outside edge of the home, but you certainly won't find me complaining. Every undersized 4' x 8' patio paired with a 4000 sq. foot house is just another project in waiting.
Home construction delays put this project so far out that I'd nearly forgotten about it, but following a break in the cold weather, the entrance walkway was finally installed last month.
There's quite a bit of work yet to do (for example, covenant restrictions require all vertical surfaces to be natural stone, cultured stone or stucco), but it's gratifying to see a harmonious setting for this magnificent home finally begin to materialize.
Updates to follow (more hardscape and then here come the plants!) ...
Aside from the undertones of
But, as I was often reminded as a child, they don't give you a medal for good intentions, so let's perform some taxpayer deconstruction of the project.
What? I'm not being fair because it's February? While it is true that last summer there was a lovely succession of color here, compliments of Echinacea purpurea, Coreopsis verticillata, Perovskia atriplicifolia, Gaillardia, and Leucanthemum x superbum, they are all now distant herbaceous memories from a half forgotten warm season.
Winter "structure" is mostly provided now by the skeletons of miniature Berberis, the carcasses of winter kill Lavendula, prematurely trimmed ornamental grasses, and the much maligned Yucca filamentosa.
(Incidentally, I swear I will punch the next person who tells me that "there's a reason they call them YUCKas". I mean, cut them a little slack, they are the only plants in this bed providing any real color for five months of the year!)
There are plenty of varieties of lavender that are dependably hardy in our area, but I'll be surprised if even half the lavender in these beds wake up in the spring. They really don't catch a break between the basalt "mulch" heat sink in the summer and snow plows and drunk drivers in the winter.
Which leads us to...
Un-shaded asphalt surfaces can reach temperatures as high as 160 degrees. A planting bed surrounded on all sides by asphalt and concrete receives a tremendous amount of this as reflective heat. What is the logic of using dark, basalt mulch in the beds to further heat up the poor plants?
Crushed basalt is also a nightmare to maintain.
Another observation: the median beds are elevated, surrounded by slope faced curbs. Perhaps a better approach would have been to match the planting grade with that of the road and install curb cuts for passive rain harvesting?
As a card carrying member of the "green industry" I'm expected to hate broadcast sprayers and embrace drip lines and micro-irrigation, but too often micro-irrigation = dead plants. This is partially due to incorrect installation (single emitters rather than grid installation), but also because our soil has lousy capillary action resulting in uneven distribution of water and poor root development.
There's a lot to like about this project- for about 8 months of the year anyway. Swapping out even half of the standard army-green Yucca filamentosa with a variegated form (Yucca filamentosa 'Bright Edge' or 'Color Guard'), or the bluish Yucca rostrata would give this planting a lot more punch during our indeterminable "gray season".
The damaged lavender along the edges of the median strip should probably be replaced with a tougher, semi-evergreen perennial that can take the heat and drive-over damage; maybe Penstemon pinifolius or Arenaria 'Wallowa Mountains'?
Since I'm feeling generous, I'll say that the crushed basalt "mulch" is slightly better than paving over a garden bed. I'd really like to see an organic mulch installed (or at least light colored, porous sandstone if you must have rock). I'm sure the crushed basalt was installed out of an assumption that an organic mulch would blow out onto the street and the rock would stay put. You can see how well that's working.
|photo credit: Ocean Blue|
Framed by two specimen sized Yucca rostrata, the unknown landscaper nailed it with a beautiful composition that wasn't quite riotous cottage garden style nor an uptight, rectilinear, modernist's garden- but rather a pitch perfect hybrid of the two. Hesperalo parvifolia, Agastache, Muhlenbergia and a half dozen other plant varieties I can't remember were combined with three triangulated, lichen covered boulders. Before I was able to take a photo (those were, after all, the days before decent cell phone cameras) all but the Yucca rostrata had been ripped out.
In it's place, someone decided to plant turf, and because the new business was an artsy, graphic design firm, a token Cor-ten weathered planter was installed with a crisp line of Equisetum.
I blame the turf indirectly on the Japanese architect, Tadao Ando and his preoccupation with horizontal planes. Many (most?) of his buildings sit at right angles to a plane of water or turf grass.
|Photo courtesy of the Clark Institute|
|Photo credit: Tomas Riehle 2004|
|Photo credit: Google street view September 2011|
Both have grown at least two feet in the last two and a half years.
My presentation strategy this year is to shock and awe my audience with a spread sheet. That's right, I'm going to Blind Them With Science!
The idea is pretty straight forward. Most of the trees in our urban forest are native to the hardwood forests of the eastern Unites States. Those forests start to disappear past the Mississippi right along a magical line of demarcation where the precipitation drops below 20 inches a year. Here are the facts of life: Mountain Home gets an average of 7.62" of precipitation, Meridian gets 10.94", Boise 11.73". No water. No trees. *
Growing up first as a Marine Corp brat and then later a Forest Service brat, our family slowly moved westward from North Carolina, to Indiana, on to North Dakota and then zig-zagged across the basin and range interior west. It was a slow motion lesson in how precipitation shapes ecology.
For my presentation, I speed up this lesson by picking a common shade tree, the Silver Maple, and track it's natural range. By finding the western edge of the range and comparing that to the annual precipitation of that edge, we can infer the low end of the Silver Maple's annual water needs.
So why just pick a couple data points? I decided to find towns and cities with the highest and lowest precipitation in every state (courtesy of weatherDB). The data backs up what we know to be true, that is, precipitation begins to taper off in Nebraska, Minnesota, Kansas and Oklahoma. West Mineral in eastern Kansas, for instance, has an annual precipitation rate of 46.89", while Coolidge on the far western edge gets 16.82".
So take a look at the numbers. Basin and range topography starts to mess with the gradual decrease in precipitation as you move west**, and there are a couple unexpected anomalies (what's with Bell City, Louisiana 30 miles from the Gulf of Mexico?), but the numbers support my assertion that an urban forest in the arid west composed primarily of eastern hardwoods is by definition an artificial construct, albeit a beautiful one.
3.8” (Prudhoe Bay)
58.82” (Sulphur Springs)
84.36” (Smith River)
7.04” (Monte Vista)
30.82” (Idaho Springs)
58.83” (West Hartford)
41.59” (Little Creek)
80.96” (Pine Mountain)
11.96” (Kailua Kona)
7.62” (Mountain Home)
42.43” (Elk River)
33.35” (Arlington Hills)
36.58” (Buck Creek)
46.89” (West Mineral)
14.93” (Bell City)
67.26” (St. Bernard)
33.6” (Saint Agatha)
23.82” (Iron Mountain)
50.22” (Lake Cormorant)
33.57” (Mound City)
7.2” (Red Lodge)
40.01” (Ocean City)
90.51” (Balsam Grove)
56.14” (Broken Bow)
122.28” (Depoe Bay)
43.58” (Block Island)
80.96” (Mountain Rest)
8.93” (Fort Hancock)
5.23” (Monument Valley)
34.42” (Brian Head)
33.64” (North Hero)
7.42” (Royal City)
115.62” (Amanda Park)
6.48” (Big Piney)
**Idaho City, for example, is 36 miles northeast and 1200 feet higher than Boise and receives 27.95" of precip. compared to Boise at 11.73".
Back in the prehistory of the last millennium, Stacy and I headed down to Florida for our honeymoon. I snapped a shot of this southern live oak (Quercus virginiana) in St. Augustine. The ancient tree looks as if it's about scoop up and run off with my new bride.
Low, lateral branches like this are a kid's best friend. Which is why, a Boise forester explained to me, city trees are limbed up long before they can develop these low branches. A pity.
A pity too that upon occasion, mature trees need to be trimmed because of clearance issues. Better to take out just low limbs than an entire tree though, and better to perform the trimming in such a way as to minimize the stress on the tree.
A new driveway is scheduled to be installed right under the large, low limb of this ash. Rather than make the Airstream slated to be parked there do the limbo, the owners asked me to trim up the tree (arborists call this "raising the canopy").
Removing large limbs on a tree creates open wounds that make the tree more susceptible to disease and pests which can then lead to decay. It's critical that pruning cuts are performed correctly to expedite the healing process. This healing process is accomplished by a process that the late Dr. Alex Shigo called the "Compartmentalization Of Disease In Trees" (CODIT). Cells form walls around the wound, effectively quarantining the area to prevent the spread of decay to the rest of the tree.
So, where and how do you make the cut? Let's take a look.
|Preparing for the first cut. (Yes. I will get off the branch first, smarty-pants.)|
Nestled in the branch bark ridge is another area called the branch defense zone. Cells in this area are responsible for the growth of woundwood that will ultimately grow over the cut.
|Woundwood callous is close to sealing off pruning cut|
These branches weigh hundreds of pounds so the standard three cut process ain't gonna work. I trim the branch in small sections, working my way in from the tip until I have a piece small enough to hold. An undercut a quarter of the way up, and a final cut from the top (carefully trimming along the branch bark ridge), and viola! A clean cut.
Remember, not all branch bark ridges are perpendicular to the trunk of the tree. Take a close look before you cut!
Half a day later...
From start to finish.
Sadly, you'll not find a single saguaro at Saguaro Canyon, but you will find a rare collection of specimen sized yuccas and Joshua Trees strangely interspersed with more commonly found Deodar Cedars and Weeping Sequoias.
An ambitious experiment in landscaping with plants of questionable hardiness, this is what Saguaro Canyon looked like shortly after it was completed.
|Ferocactus wislizenii and friends....|
At the entrance you're greeted by a who's who list of Sonoran/Chihuahuan superstars. And, just to make sure you get the subtle vibe of the place, massive slabs of Arizona sandstone were installed as a backdrop.
A sexy night time shot a little further in illuminates Yucca filamentosa x thompsoniana, Yucca brevifolia, Cylindropuntia imbricata, Agave havardiana, Fouquieria splendens and Opuntia x somethingoranother.
I stopped by a few weeks ago in the bitter cold to see how our southwest friends were holding up. By this point, I figure that we should be able to get a decent sense of what will survive and what won't.
Let's fast forward five years after the installation was completed ...
|On a cold and snowy day...|
The sandstone is still there, as are the Deodar cedars, the weeping sequoias and spruce....
Cercocarpus trimmed into tidy little snow cones.
Why stop there? Surely the Chrysanthemum nauseosus could be trimmed into fish and flying monkeys?
So, we've got a clear idea now of what will survive in southwest Idaho, right?
Sure, I didn't expect the Ferocactus wislizenii or the Fouquieria splendens to overwinter, but what happened to the hardy Opuntia or the Festuca idahoensis? I think this hints at some irrigation issues, but it's hard to pin down how soil, drainage and other factors played into the plants' success or mortality rate.
I'm pleased that the Idaho Botanical Garden now has a xeric test garden where these factors can be measured and controlled. In a couple of weeks I'll be sharing a picture tour of that as well.