Category Archives: Trees

Toward the Formation of The Central Oregon Tree Explorers

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Paleontoiogists say that we first evolved as a species on the African savanna, that mixed landscape of grassland and scattered trees. Some argue that we were first a tree associated species. Be that as it may, most people have an affinity for trees today. We have our favorites. We plant them for food, as a source of material to meet various needs, for shade, for that inexplicable feeling we have when amongst them, in support of the life that came before, those dynamic communities, their complexity and the vitality, that define these places we now occupy, for their beauty. In Central Oregon with our arid to semi-arid climates, those with annual precipitation as high as 15”-20”, xeric referring to our dry summer growing season, our native trees serve as an indicator of the possible. Our local landscapes have curvilinear boundaries, that delineate areas with like moisture regimes. These go a long way in determining the native landscape (But not all of the way!).
14” of precipitation locally is roughly the bottom limit for Ponderosa Pine. You can see this as you observe grouping and the massing of tree species, forming a line from south of Bend, west and north to Sisters, then along Green Ridge and north to the Columbia. There is an in-between landscape, an ecotone, where the Ponderosa intermingle with the Western Juniper, which dominate easterly, until the average drops below what even that reduced amount can support. The ecotone roughly bisects Bend. Continue reading →

On the Creation of an Urban Tree Canopy Management Plan for Redmond, Oregon

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Trees can be a defining element of a community as a ‘success’ story, a failure or somewhere in-between. A community’s trees are of it, not some separate amenity provided by the City. Ideally, just as the canopy is part of a community, its care should be a part of the shared responsibility of the community, with the City providing the services the community cannot, in addition to their role of coordinating the care so that the tree canopy can provide the highest level of service while meeting aesthetic needs. The City is ideally situated to perform this role. Neither ‘group’, the community or the City can do this on their own. Training, education, outreach, project implementation (planting, tree care) are a joint responsibility. Leaving this as a City responsibility alone cannot result in the best product. Communication and partnerships should define the relationship and effort.

Picking numerical targets for increasing overall tree canopy misses the mark. We don’t just need numbers, we need site and species appropriate trees in order to grow out a healthy urban canopy that is neither water intensive, given our climate and declining aquifer, nor one that increases overall wildfire risk; one that helps us, a portion of the more powerful human residents, bridge the gap between the contrived landscape in which we spend most of our lives, and the wild, evolving landscape outside our communities, that operates in ways that balance all the competing and supportive needs, of all of the species that comprise it. Our ‘developed’ communities, heavily prioritize a narrow fraction of the lives within them.

Tree selections should be supportive of local wildlife and pollinators in addition to providing the environmental services associated with urban tree canopies…not just those of the decision makers within the human community. Planting the wrong trees to get initial numbers up, as some kind of marker of success, will be relatively short lived at best. Trees are a long term, living and growing investment, that shape the future. However we slice it, they will demand water in larger amounts as they grow over time. So our choices should be thoughtful and considered. At issue is whether the normal growing conditions can adequately support the growth of chosen trees. We know that almost any other tree, beyond our Western Juniper, will require supplemental water. How much though we need to weigh. When tree and climate are a mismatch the result is evidenced locally by the increasing numbers of shade trees around town where owners have turned off the water leading to stressed and dying trees. Success is absolutely dependent upon well chosen trees, their ongoing care and the participation of an informed public.

 

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Tree Planting Problems at Dry Canyon Village

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The reversion on this competing leader threatens to dominate the canopy if not removed. The planting appears good, straight trunk, well staked. It is always what is below ground, that is not readilly visible, that’s critical.

When I was still working for the city of Portland Parks, one of my jobs, for a number of years, was to do design reviews and construction inspection on big capital Parks projects being built from scratch downtown including South Waterfront, Caruthers, Jamison Square, Director’s Square,Tanner Springs and The Fields. I’d attend meetings with our project managers and the landscape architects, charged with assessing the appropriateness of their plant choices given their requirements, the site conditions, our capacity to provide the necessary maintenance over time, whether their combination presented conflicts, without commenting on the aesthetic of their designs, which was considered outside my expertise. Sometimes I was asked to do the same for projects in other areas. I’d visit the project sites regularly to observe prep work, planting and follow-up care, suggesting changes to the contractor and writing up my report. The architects generally approved, or rejected, the plant stock coming into a job, accepting or rejecting substitutions. It was my job to make sure that plants were properly cared for on site before planting, the prep appropriate, that they were planted properly and cared for over the first year of establishment. Continue reading →

The Nutrient Cycling Role of Fire in Central Oregon’s Arid Landscapes

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A Juniper like this one, growing out on BLM land around Cline Buttes, attains this squat and sturdy stature only after hundreds of years. Growing as they do on shallow, raised rocky areas, not only do they grow slowly, but there tendency is to caliper up. In irrigated pastures, these grow overly fast, spindly and upright. Look at that taper!

Ecologists will regularly claim that fire plays an essential role in the life and dynamics of the Juniper woodland, our sagebrush steppe and the grasslands of our arid and semi-arid plant communities, that without it, the landscape will deteriorate. Okay, but what does that mean? How can fire actually lead to a landscape’s improved vitality and diversity? What does fire actually do and what happens when it is eliminated? The short answer is that fire, in burning the collected fuels on the ground, breaks them down and returns them in nutrient form to the soil and the cycle of life. It provides the space necessary for a healthy and diverse landscape. To get there requires more thinking.

First some essential definitions and clarifications are needed: what are these ‘types’ of landscapes that together can be found in the arid reaches of Central Oregon; all landscapes are dynamic, evolving, changing over time according to the forces in effect on them, they are not static or fixed; what is meant by arid and semi-arid; fire, what is it, what is actually occurring when something ‘burns’; what is going on at a molecular level when an arid landscape burns; if this is so necessary, what fulfills this role in wetter landscapes; what’s the relationship between fire, rot and digestion; how, and does it, serve the nutrient availability and the necessities of organic growth. In understanding these basic parts we can better understand the self-renewing CYCLE of life as an ongoing process and how disruptions to it negatively influence its capacity to continue. Continue reading →

On Ornamental Trees and the Remaking/Unmaking of Place: Revising the City of Redmond’s Tree List, part 2

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How Much to Water?

Recommending trees from climates with significantly wetter growing seasons needs to stop if we are to continue growing our population. Landscapes as designed, and managed, are the single largest user of residential water. Recommending trees which ignore this problem is irresponsible. Lower water use residential landscapes are possible. Local codes and recommendations must, however, reflect this priority.

Additionally, how much to water is a bit of a mystery to all of us and especially so to non-gardeners. How much? How often? Our watering practices should be determined by the local precipitation and the tree’s needs. What is commonly done, however, is that we water for our lawns and that largely determines what our trees receive, unless we have separate drip systems. A tree’s root system doesn’t stay neatly between the lines. They quickly extend out well beyond the span of the tree’s leafy canopy. In many cases even 2-3 times as far, taking up water and nutrients. A roots of a tree, planted in a small bed, adjacent to an irrigated lawn area, will move out into the lawn. A tree isolated in a xeric bed with only a few drip emitters, will quickly demand more than such a meager system affords it and such a tree, if it requires summer moisture, will struggle while competing with its nearby  ground level growing neighbors. Again ‘neighbors’ should share compatible requirements so all can thrive on the same ‘diet’ and moisture regime. Continue reading →

On Ornamental Trees and the Remaking/Unmaking of Place: Revising the City of Redmond’s Tree List, Part 1

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Perhaps an odd tree to start this with, Juniperus scopulorum ‘Woodward’, is not a ‘shade tree’. It is not deciduous. It is a narrow, fastigiate form of Rocky Mtn. Juniper that, growing to a height of 20′ with a 2′-3′ spread can serve as a formal accent in colder climates like ours, a ‘replacement’ for the more tender Italian Cyperss, and it can do quite well here with very little supplemental water.

Trees, specifically ornamental shade trees, have become an expected and desired part of our urban lives, at least util their leaves fall and await our cleanup. Many associate long tree lined streets and avenues with urban living. Broad Maples. Lofty Elms. Plane Trees and, in tighter spaces, perhaps Cherrys, Crabapples and flowering Plums. Urban trees provide several notable ‘environmental services’ increasing our comfort level with their cooling shade, their capacity to remove pollutants from the air, cover and nesting places for birds, food sources for the insects which the birds rely on and the sequestration of carbon. Trees are generally viewed as a public good, necessary even for our lives. We can get quite emotional about them. So it seems a bit ‘wrong’ to suggest that this ‘ideal’ may not always be ‘best’ or even desirable.

Broadleaved deciduous shade trees are ‘naturally’ members of mesic, temperate to cold-temperate regions of the world. That is where they evolved and where when we plant them out, where they do best. When we begin planting them outside of their historic natural ranges, especially when we ignore the conditions, the disparities and the extremes between their natural ranges and those where we choose to plant them, then we can have some serious problems. The trees may struggle along, or if we remain committed to making up for our local area’s lacking, usually in the form of supplying more water, they can do reasonably well. But this suggests possible real problems as one moves further away from the conditions of a tree’s natural limits and increase the numbers planted out. Where is this water coming from and what are the impacts of removing this water from its normal and healthy cycling of which it is a part? What will be going without? And, is that cost worth the losses it creates? Our selection and planting decisions depend on how we value that which is lost! In short, the typical deciduous shade tree of our imaginings do not belong here in a desert. Continue reading →

Spruce Park, Redmond’s Newest Park and Our Neighbor: a horticultural critique

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Redmond’s Spruce Park looking NNE from the SW corner toward Gray Butte and Smith Rock in the background. The border beds which follow much of the loop path are ‘native’ plantings according to the conceptual plan. It is common to claim that most of the plants are natives in designed natural areas, but native is not synonymous with ‘natural’. Although natives are used here concessions have been made including such plants as Echinacea purpurea ‘Pow Wow Wildberry’ and Rudbeckia ‘Goldsturm’. In a strict sense Ponderosa Pine aren’t native to this immediate locale either, they require more precipitation than we normally get and the Autumn Blaze Maples are a hybrid of two northeastern North American species.

A landscape, in nature, is a whole, functioning system, capable of perpetuating itself, through out the seasons and years, relying entirely on its own conditions and the cycling of energy and resources occurring on and within it. This is also the definition of a modern sustainable landscape. Ideally they require no inputs or energies supplied from offsite aside from the sun, precipitation and the normal cycling onsite of nutrients and water. A human made, contrived landscape, as all of those built by us today are, may be ‘judged’ by how well they function on ‘their own’, by how well they fit this ideal. Labor and outside inputs necessary to maintain a landscape are then indicators of how out of balance, how far from ‘ideal’ nature and genuine sustainability, a landscape is. A contrived landscape, which ignores the relationships integral to a healthy landscape community ‘demands’ more and more maintenance and support. Given its design and use, a landscape which ignores its site and relationship requirements will deteriorate from the intended design, losing to death component plants while gaining, increasingly, more unwanted available weed species. Design, conditions and use are essential to determine, in this sense, what a ‘good’ landscape is. Continue reading →

Why Bad Things Happen to Good Plants?: On Root Problems, Root Washing, Nursery Practices and Customers

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“To be, or not to be? That is the question—Whether ’tis nobler in the mind to suffer The slings and arrows of outrageous fortune, Or to take arms against a sea of troubles, And, by opposing, end them?”  Hamlet.

Is the question we face as gardeners as simple as, To ‘root wash’ or not to ‘root wash’, before planting?  To some today it has become ‘heretical’ to suggest that it might not be just a necessary corrective, but an unmitigated good…and not doing so dooms a plant to failure.  The practice of ‘root washing’ in its present form, is relatively new to gardeners.  Horticulture, which is a system of techniques, traditions and science, that goes back to our own species’ first intentional involvement growing and selecting plants, has not always included it.  Practices develop over wide spans of time.  Many are retained, others pass away. Root washing has been around as a method to assess damage to root systems, to ease and make more efficient division, to study root growth or cleanse them of particular infestations.  ‘Bare-rooting’, during a plant’s winter dormancy in temperate regions, has historically been done in the field when harvesting or transplanting many deciduous trees and woody plants for shipping and ease of transport.  In some circles today root washing has become an almost literal flash point, pitting proponent against opponent, ‘science’ against ‘tradition’…yet another fracture line to divide society. The road of the absolutist, as with many other human practices, tends to create conflict as evidence of correctness is lobbed back and forth.  My own view is that, like so many other things today, the subject is somewhat ‘grayer’. Science can be on both ‘sides’, or neither, and reality is rarely so simplistic. Continue reading →

The Strength to Stand: Surviving the Load of Ice and Snow in Portland

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The morning after the big snow along the front of my house. To the left, splayed out and weighted down, is my Butia capitata. This one, from Argentina and not used to snow, had me worried, but it sprung back. The Oleander to the right, next to the sign, was bent down to the ground from its 8’+. Further back is one of my Chinese Windmill Palms, Trachycarpus fortuneii, bent under a snow load it is used to from high in the mountains of southern China.

Many of us who garden in the Pacific Northwest, and especially those of us in Portland this year, will be visiting our garden centers and favorite nurseries this spring and summer with a little more anxiety and need as we look for plants to replace those that have succumbed to this winter’s cold, ice and snow loads, all of which were more severe than what we have come to expect here.  But before we pull on our boots and don our rain gear to head off for shopping there are several questions that we need to consider before we make our purchases.  Not all of us draw up plant lists, but most of us at least carry in our heads a wish list of plants we have seen in other gardens, in magazine spreads and while on vacations, but if we want to avoid some major mistakes and move our gardens toward the kind of landscapes that we really want, we are going to have to put on our reality goggles and critically assess our choices…that is, if we want to avoid unnecessary losses in the future. Continue reading →

Summer Tree Failure

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A failed Norway Maple on SE 49th. This picture was taken June 28th, five days after a big rain event. You can see that this tree has been struggling for some time as evidenced by the dead branches still in its crown and the stressed flagging leaves up there. The girth of the trunk is greater than the width of its planting space. It is pinched beneath the overhead lines and the requirements for street trees regarding road clearance. It’s height has been ‘controlled’ and limited over the years.

Trees fail all of the time and when they are older, this can be quite spectacular, or devastating, if your car, home or an individual have the misfortune of being in the its path.  Like most people I used to believe that most such failures happened as the result of storms, and many do, but it is relatively common for trees, or major limbs, to come crashing down with calm conditions in the Spring. The new flush of growth brings with it a great deal more tissue and water weight than a tree in active growth has previously supported or, for a tree struggling, compromised by the burden of significant rot in its core and/or limbs.  Look at any tree and look at its girth, its canopy spread and on many species, its long, often horizontal limbs and try to imagine their weight.  To help with this fill a couple of buckets with water, lift them and try to hold them horizontal away from your body.  Trees are static structures, comprised of countless overlapping fibrous layers, much of it hard and rigid with a great deal of compression and torsional strength.  The were ‘born’ for this.  Few of us would last for more than a few seconds trying to support so much of our own weight on extended arms.  We shouldn’t be surprised when they fail, even as elegant and as well ‘engineered’ as they are. Continue reading →