Parrotia persica, Persian Ironwood, has long been among my favorite trees, for its leaf shape, substance, fall color, the overall plant form and for its exfoliating puzzled bark. Hardy to zn4 this plant is tough as nails here requiring no protective effort at all.
[A note to the reader. This is not a scholarly treatment of all of the peer reviewed material on this topic. There are no footnotes or listed sources. This is a product of my more than 35 years of horticultural field experience and gardening along with what I’ve gleaned from reading several technical peer reviewed articles on the subject. Such material is difficult to read and can be off putting and intimidating to even the educated layperson. This posting is my attempt at interpreting the research and reviews that I read in a way I think is understandable without overwhelming the reader with bi0-chemistry and the technical esoterica scientists must consider in their pursuit of understanding. Any faults are mine.]
I’ve been thinking about plants and their response to cold having watched the deciduous trees drop their leaves, dug tender plants out of the garden and moved pots around to where they would be adequately protected from freezing temperatures. We all know what happens to water when it freezes, going from a liquid state to a solid one, its molecules forming crystalline structures, expanded and rigid, responsible for burst water pipes and snowflakes. Water possesses some amazing qualities, as a solid, kind of counter-intuitively, it becomes less dense floating rather than sinking even taking on some insulative qualities and stopping the convective flow of heat that is normal in liquid water. At the instant of freezing water releases a small but measurable amount of heat. What happens inside plants when temperatures drop below freezing? How does the plant keep from bursting its own cell walls like the water in pipes within an unheated crawl space or wall cavity of a building? You’ve seen what happens to plants like Coleus and the sodden black heaps they become upon thawing out. Continue reading →
Looking south from the top of the stairs at the Bybee Stop. This is pretty much the same view as looking north with respect to the landscape. BNSF’s tracks lie to the left, the east. The railroads have their own ‘landscape’ maintenance standards set primarily for safety reasons. Within so many feet of their tracks they have a zero tolerance for plant growth and use sterilants. There is also a zone within which the will ‘brush back’ trees and shrubs to keep site lines open. Metro will have its own standard. The two side by side show their combined effect. Also, typically railroads do not fence off their tracks making clear sight lines a more pressing safety concern. Trimet has fenced off the tracks from casual pedestrian ‘conflicts’. Fencelines are problematic for maintenance unless ‘dead zones’ are expanded to include both sides.
Heading south of the Harold St. overpass the Orange Line leaves the most urbanized portion of its route, or at least its most densely populated stretch. Traveling south to the Bybee, the Tacoma/Sellwood and then the Milwaukie stops, the line run alongside the BNSF tracks and there is very little ‘landscaping’ of the corridor. The railroads contract out maintenance of their thousands of miles of tracks. (For a brief look into their approach check this link.) Continue reading →
This shows the banded pattern common today in long mass plantings each swath a single species going for a kind of landscape scale ‘graphic’ pattern that is less concerned with ‘fit’. This is near the Clinton/ SE 12th stop.
Size matters. In horticulture it changes everything. Things that are inconsequential, or maybe even enjoyable in the backyard garden, can quickly become daunting or onerous when the scale is ramped up. Working at a commercial or institutional scale has to change your entire approach to the landscape. In a small garden it is easier to accommodate mistakes, the conflicted combinations and those issues of horticultural ‘fit’ that we missed when we design or install. Scale, however, rubs our faces in it everyday, makes us pay with aching backs as unintended consequences play out across the thousands of sq.ft. and acres. It becomes a matter of physical survival and undermines your professionalism. You become perforce part laborer, part diagnostician, designer, plantsman and critic….Out of necessity you sharpen your critical thinking skills and the last thing you ever wanted, your sales skills, as you work to sell your ideas to management who are absurdly ignorant of the problems you face everyday in the field. And, then, eventually, you retire, but you don’t turn it off…you can’t.
Which brings me to the MAX Orange Line and its landscapes. When I did horticultural design review for large capital Parks projects, it often felt like a dueling match. I would pour over the design, whatever the stage it was in, match that with my particular knowledge of site conditions and my maintenance experience within Parks. I would state my concerns on paper and in meetings with the Project Managers and Architects. I was stubborn and consistently found myself up against a process that undervalued horticulture and my input. Good horticultural practice was regularly placed in a losing position opposite not just that of the Landscape Architects but of a very political process that tried to give the public what it wanted as long as it fit within the Architect’s vision. Horticulture always came out a poor third, even though good horticulture always saves money in the mid and long runs. It was exasperating. The public, by and large is ignorant of horticultural practice and no effort is made to educate them at any level. Continue reading →
Holgate Overpass – the northeast approach. This was taken Aug. 28 of the landscape cut down in April showing regrowth in a hot drought year.
Holgate Overpass Update:
It finally rained this last weekend! Somewhere around .3″. Woohoo! It will be the most rain that we’ve received since March. It’s been dry! In April the City cut down the ‘weedscape’ on the northeast approach of the Holgate Overpass. It’s rained very little since and we’ve had record warm temperatures all summer. No one has come back to spray, plant or do anything. No one’s even picked up the trash. If you compare the four ‘weedscapes’ on the two approaches they are very similar. The NE, by volume has had the most regrowth. This is for two different reasons: first, this site was cut earlier in the season when there was more moisture still in the soil to enable regrowth, and secondly, because the site is dominated by Blackberry and Tree of Heaven, both perennials, well established and of larger stature than the plants dominating the other approach landscapes. Continue reading →
The upper portion of Duniway Park. A Nyssa sylvatica growing at the toe of the slope below OHSU. The turf is completely unirrigated, is very compacted and has poor drainage. Much of this turf is dominated by a few broad leaf weeds while most of the grasses that survive are weedy as well. The whole Park is built over one of Portland’s first dumps.
I wrote what follows a couple of years ago while still a horticulturist with Portland Parks and Recreation. It was an addendum to a piece I wrote addressing a different approach for prioritizing work in Park landscapes and is reproduced here, with slight changes, as i originally wrote it. I thought of it more recently as I’ve watched Portland bake this summer and observed, consequently, the decline of residential and Parks lawns. I am a big proponent of ‘sustainable’ landscapes. That does not prevent me from seeing the necessity for grass lawns in urban areas especially in cities as they follow the path to increased density for sustainability issues as well. People ‘need’ open space and as we all ‘suffer’ from our own shrinking of private outdoor space, the need for such public spaces increases. But turf cannot fill the need if it is poorly maintained. Dormant, dry, compacted weed dominated lawns are both unattractive and less functional. Open spaces are not all the same. Ugliness can degrade them to the point of rendering them almost useless in terms of their human value (We often speak of habitat value for wildlife and in terms of water quality. We spend less public time discussing what is of basic human value. What we require to meet our very real and ‘animal’ needs. Not all of our legitimate needs can be met by buying products and services.)
Vigorous grass based turf is not sustainable. It is a monoculture susceptible to weed invasion that requires regular care, including, irrigation, mowing, fertilization, aeration to reduce compaction, occasional dethatching, control of moles and, for the best stands, the occasional well timed application of an herbicide and insecticide. Having said this, I still see it as a vital component of our Parks. Portland Parks and Recreation has other priorities making exceptions Park by Park, though select athletic fields for playability and safety reasons are still irrigated. (Other Parks Districts, notably places like Bend, OR, with a desert environment, have prioritized having good quality turf in public areas). No other surface provides the functionality and value of turf grass in an urban environment. It absorbs rainfall; reduces the problems of mud and dust and helps control the erosion that accompanies bare soil; provides a firm, but shock absorbing surface for activities; aids with cooling the urban heat island; provides a restful carpet of green that helps calm a potentially chaotic visual world; and, provides a surface for young children to play on or family and friends to relax or picnic on. As urban density increases, the need for public open space increases. We need lawn. Concrete, pavers and asphalt will never fill all of this need. An argument can easily be made that rich healthy lawns better fill this human need when they are in Parks than scattered thinly through residential neighborhoods in front and backyards where they are individually too small or inaccessible to meet the public need. Continue reading →
I had a novice gardening friend ask me the other day about planting the dry, xeric, part of her yard. Many of you know how abnormally dry and warm a spring/June it’s been here. Those of us with gardens requiring routine irrigation started a few weeks ago and we’re expected to be heading into an extended hot/dry period over the next 8 or 9 days with temps over 90 F. (While it is not unusual to experience 80+ deg. days here in June it is unusual when you look at our overall pattern this spring. Remember that we can also have Junes where it is common not to get out of the 60’s with our famous Portland drizzle day after day while we wait for July and the ‘beginning’ of summer.) She was anxious to get her new plants in the ground and was asking me about amendments as the soil was baked and hard…. Continue reading →
This is the section south and adjacent to the west approach. It was rough mown in early June down slope to the Blackberries and east to the Box Elder in the background. You can see the blue flowers of the Chickory and the Fennel.
Walking the Holgate overpass across the Brooklyn Switching Yard, with its adjacent container operation, is anything but pleasant. Trucks, trains, blasting horns and the four lanes of traffic whizzing by next to the 5′ wide sidewalks wipe away the positives of the views across the river and to downtown. Most people probably don’t think of places like this as ‘landscapes’, but in the broader sense they are. Landscapes, most simply, are the places that we occupy, whether they are artfully designed, narrowly utilitarian, neglected, forgotten or simply dismissed. They become ‘landscapes’ through our occupying them or merely perceiving them. They are places we are in relationship with. Holgate is a traffic corridor for automobiles. Here is where it crosses the north south railroad line and the region’s major container handling yard. Car and truck traffic are heavy, at times, nearly non-stop. This is the only east-west route between Powell Blvd. and Bybee, and Bybee is intended for, and used by, more local traffic. It is loud. Traffic typically is moving a 35-45 mph although it’s posted 30. The sidewalk is relatively narrow and this zone of unpleasantness is over a third of a mile long, an expanse from which there is no ‘escape’ for the pedestrian beyond enduring it. Since I retired, and weather permitting, I walk it once or twice a week on my way to the gym for a swim. Continue reading →
The second grassy bay from the south end, below the Harborside Restaurant at Riverplace, between the Taxodium clumps. The ’04 planting included no shrubs or perennial forbs in this area. It was a monoculture of Koeleria macrantha, a native early season bunch grass that goes dormant by mid-July leaving the entire area vulnerable to invasion by weeds and offering no ‘barrier’ to either people or dogs, which enter frequently. A sweep of Cistus pulverulentus ‘Sunset’ at the bottom, Ceanothus cuneatus ‘Blue Sierra’ at the left and Arctostaphylos x ‘Harmony’ have been added to this site along with Festuca rubra var. commutata a low, fine textured spreader to help fill in the spaces and scattered native perennials.
Part of the Over Thinking Series
We, all of us, are part of the urban landscape. The lack of connection, understanding of and regular involvement with our landscape, a condition which has become pervasive in modern society, sometimes referred to as NDD, or Nature Deficit Disorder, has brought us to the rather precarious place we are today, with the rapidly declining state of our landscapes and a general ignorance amongst the public and our leaders of the severity of the problem and our responsibility to correct it. We are locked into an old strategy that views landscape as incidental, the natural world as backdrop and not central to our own well-being. As long as it meets a narrow idea of our needs, a modern minimalist aesthetic and does not over tax our ‘pocketbook’, we have been okay with it. From a horticultural viewpoint this is becoming an increasingly deteriorating disaster, something that not only we can do something about, but one that it is imperative that we do so. Adaptive Management is a positive and workable strategy we can adopt that will begin to turn this situation around. Continue reading →
Last week, in Part I of this two part series, “Bee Deaths Mystery Solved? Neonicotinoids (Neonics) May Actually Help Bee Health”, we explored the claims by Harvard School of Public Health researcher Chensheng Lu, heralded by anti-pesticide and anti-GMO advocacy groups, for his research that purportedly proves that the class of chemicals known as neonicotinoids are killing bees and endangering humans. And we saw how many journalists, our of ignorance or for ideological reason,s promote dicey science.
(Some advocacy groups have latched on to Lu’s work looking for legitimacy and support. There has been a growing community of resistance to much that has been going on in the agro-chem-gentec industry that pre-dates Lu and his research. They have been challenging the multi-billion dollar industry on multiple fronts. On the other hand, it only takes a little checking to discover that Lu is often viewed as a ‘liability’ within the scientific community and a hinderence to their efforts by many in the community who have been advocating for good science in the political process that regulates these industries. They did not choose Lu nor do they now claim him as their champion. Entine, in his previous article strategically chose Lu as a ‘straw dog’ to represent his opposition, the “anti-pesticide and anti-GMO advocacy groups”, a target that he could then ‘tear down’ and then apply to the opposition groups as a whole, as if Lu, with his biases and ‘sloppy science’ were truly representative of them. In these articles, at least, Entine gets to choose. This strategy isbecoming increasingly common when ‘industry’ and their front men, under attack, seek to ‘confuse’ the public thus reducing political pressure that might seek to limit them and their ability to conduct ‘business as usual’.Continue reading →
Trachycarpus fortunei – My oldest Palm tree. The house’s gutter is at 13′. This is the most robust, stoutest, of the 5 T.f. that I have with the broadest canopy. It’s male. I’ve just finished cleaning up its rattiest older fronds. I remove 15-20 every year and have been annually while it’s been in its adult active growth phase. It will slow down when it begins to approach its maximum height and maturity.