Category Archives: Plant Selection

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 →

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 →

Weeds: What We Need to Do at DCVS

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Looking NE from the gate at Northwest Way, other than a handful of juvenile Juniper there is literally nothing native of value across this roughly 9 acre spread. The other two undeveloped phases are equally bad, having a similar mix of weeds.

The question I keep hearing is, ‘What do we do?’ Many, if not most people living here now, have expressed frustration and more about the Dry Canyon Village South, DCVS’s, landscapes, specifically the berm, the mini-parks,  the Circle and the 25+ acres of undeveloped, uncared, for property we share space with. They ask me because they know I cared for Park landscapes, as a field horticulturist, for almost 30 years, Parks which often included natural areas of over 100 acres, to little neighborhood parks and intensively developed and used urban parks in the downtown core. I also haven’t been shy about my criticism of the lack of care, or of even a plan, for the neglected property we are saddled with. Anyone who has cared for a landscape can see the problem here. Leaving disturbed and neglected properties on their own is not a plan and can lead only to their further deterioration and continuing, worsening, ‘weed pressure on the adjacent developed landscapes. Continue reading →

Agapanthus for the Maritime Pacific Northwest: Not all of these are well suited for us…or are they?

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Agapanthus ‘Hinag’ syn. ‘Summer Gold’ a Japanese selection brought to the US by Barry Yinger.
Agapanthus ‘Peter Pan’
Agapanthus ‘Storm Cloud’
Agapanthus ‘Tinker Bell’

A fellow gardener asked the question about whether there were a list of sure thing Agapanthus, plants that a beginner could confidently choose and have success with in most of the maritime PNW.  I’m going to say no.  All of these are South African natives and while many of us can grow these in our gardens, because our conditions overall are marginal, a gardener is going to have to possess a good understanding of their site in particular and some knowledge of the cultivars that they are choosing.  I’m going to borrow here from Manning and Goldblatt’s book, “The Color Encyclopedia of Cape Bulbs”, which discusses the bulbs of the Cape Floristic region and those adjacent areas spilling over into other parts of South Africa. Agapanthus species are native there, endemic in fact, occurring naturally no where else in the world.  I’m also relying here on the SANBI website, the South African Natural Biodiversity Institute which has put together an incredible national program, which all countries should be building for their own countries.  Being a South African plant aficionado I visit it frequently. To this I add my own observations and speculations, having grown several Agapanthus over the last 25+ years in Portland: These come from warm temperate and subtropical areas in South Africa, 10 species total, 3 limited to the Cape itself, all of which tend to occur in rocky grasslands.  Other botanists have downgraded 3 of Manning and Goldblatt’s species and given them subspecies status recognizing only 7 species. Continue reading →

Gardening in Public, Charismatic Mega Flora and the Need for a Public Horticultural Intervention

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We ‘need’ charismatic mega-flora today, plants that scream out to even the most plant blind of us to take notice, those that create such a sudden and uncontrollable ‘stir’ within us that our simple glimpse of them breaks our momentum, our chains of thought, interrupting whatever we’re doing in that moment bringing about a reflexive interjection, cause us to take notice, create an uncontrollable urge to stop what we’re doing and come back for a closer look!  To tell our parents, partners or friends, to drag them back, for a repeat performance or to see if what we saw is really there or merely a mistake of perception.  And they do come back.  I see them every day, sometimes dragging disinterested friends to see this unimaginable impossibility.  I hear them when I’m out working in the private part of the garden with excited voices, sometimes expletives, “Look at this ‘F@#$ing’ thing! Can you believe it?”  I love this. They’ve come for ‘Monte’!

  • Checking on my latest science experiment. credit Doreen Winja
  • At this point: the rosette remains about 6′ in diameter, overall height is 13′ 4″, the circumferance averages about 43″ around the swelling terminal end which is about 30″ tall itself. I’m 6’2″ and I’m on a 10′ orchard ladder. credit Doreen Winja
  • The flower buds rising out from behind the bract on its secondary peduncles, branches, after having emerged from what looks like a ‘red’, raddichio colored envelope, showing between the buds and bract.

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Puya: Growing These Well Armed South Americans in the Pacific Northwest

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[I wrote this originally about 2 years ago as part of what turned out to be a too long look into the Bromeliad Family.  Here I present only the genus Puya spp. in an edited form with the addition of the species Puya berteroniana.  Go to the original article to read about the shared evolution of the several genera and families that comprise the family, why these are not considered succulents and a look at the armed defenses of many plants.  My plan is to breakout at least some of the other genera as well as I think the length of the original post may have put some readers off.]

Puya: one of the Xeric Genera of Terrestrial Bromeliaceae

Puya chiliensis
The inflorescence is very ‘spiky’ in its structure its many ‘arms’ covered with buds.
Each bud will open over time giving a long season of bloom.

The name “Puya” comes from the Mapuche Indian word meaning “point” (The Mapuche people are indigenous to Chile and Argentina.  They constitute approximately 10% (more than 1.000.000 people) of the Chilean population. Half of them live in the south of Chile from the river Bío Bío to Chiloé Island. The other half is found in and around the capital, Santiago and were mostly forced to the city after Pinochet privatized their lands giving them to the wealthy.)…the assignation is clear and the pointed, spiky, nature of this genus is immediately obvious to anyone.  But there is something easy and comfortable about the sound of the word in your mouth when you speak it…poo-‘yah.  Puya are native to the arid portions of the Andes and South American western coastal mountains.  (Oddly, two species are found in dry areas of Costa Rica.)

Puya spp., populate arid western regions of the Andes Mountains up into southern Central America.  These are terrestrial plants, relying on their roots to find the moisture that they need.  They possess the same basic rosette structure common to all members of the Bromeliad family to which they belong, including their petiole-less leaves, which clasp directly to a compact stem structure, funnelling the infrequent, and seasonal, precipitation they get into their crowns and root structures where they can take it up, a strategy very similar to Agave and Aloe which grow under similar conditions. Continue reading →

Winter 0f ’18 -’19: Cloudy, Mild With a Chance of….On Weather, Zones & Plants

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The center green band of these NOAA charts delimits the 20 year average for each day, the bottom marking the average minimum temp and the top marking the average high temp. The red and blue portions of the chart mark the range of temps between that and their record high and low levels. The dark blue ‘bars’ show the actual recorded temps for those days. This chart shows distinctly the initial cold span with the slight warming to well within normal range, followed by a more irregular cooling. The relative steadiness of these temperatures helped plants maintain their slower, more dormant metabolisms for the month. Typically February has been notable for the stability of its daily temperatures, the relative narrowness of the ‘green, normal, band’ indicates this.
This chart for March again shows the slowly warming/rising light green normal band contrasting with the dark blue bars of our actual temps. The March temps appear colder because they shifted the chart downward. The more extreme minimum temperature swings of Nov., Dec., and Jan. have even out, the lt. blue portion narrowing and showing more consistency.

It’s 41ºF at 5:30am on Mar. 12 as I begin to write this.  We appear to have come out of the longest sustained ‘cold’ period of the winter of ’18-’19 which began on February 4 and continued through Mar. 11, a period of 36 days.  Over those days we had freezing minimum temps at PDX, the official NOAA reporting station for the Portland area, on 26 of them.  On two of those days, Feb. 6 and 7, PDX recorded the winter’s lowest temp, 23ºF, making it a zn 9a winter, mild for us historically and especially so for the temperate US as a whole, much of which was experiencing its own much colder temps.  It’s mid-March and our high temps have climbed well above what they were and our forecasts call for milder, more ‘normal’ highs and lows now locally.  It looks likely that not only are we going to be on the ‘warm side’ of normal, but that our lows have shifted into a pattern well out of the freezing range.  (State ODF meteorologist, Pete Parsons, calls for a pattern of slightly warmer and drier weather than normal over March, April and May with the highest chance of this during May.) 

While weather consists of moments, recorded data points, we attempt to make sense of it in its patterns over time…our experience of it.  In this we are much like our plants.  Plants too have their ‘expectations’ of the weather and those conditions that take them outside of them, outside their familiar patterns, the relatively quick changes and perturbations, as well as the longer sustained patterns, and extremes, are ‘noticed’ and make a difference.  How does this winter compare? Continue reading →