The Fields (Click here to see the final design plan), completed in spring of 2013, is Portland’s newest Park in the north end of the Pearl District. While I was still with Parks I did the horticultural review during the design process and was an on site inspector, periodically, during construction. New Parks like this one require a huge time commitment by Parks. Selection of designers, outreach to all of the stakeholders and many other meetings involving more technical aspects of such a project all in an effort to deliver to residents a Park that is beautiful, serves the needs of residents and is affordable in terms of long term maintenance. Before the project is offered to the design community functional goals are set for the Park and a general design theme is chosen. Various firms offer proposals. Concepts are bandied about. Eventually, one is chosen. In this case, the Office of Cheryl Barton, a San Francisco firm, was awarded the design contract (To see what they have to say about it).
This Park is the third in a short ‘string’ of Pearl Parks, all of which would be tied together thematically by water features, their highly urban setting and an Ipe boardwalk. It was part of the Portland River District Park System Urban Design Framework Study (January 2001). (A fourth Park, across Naito Pkwy, Riverfront Park, remains to be done.) Two Parks lay to the south of here, the nearest, Tanner Springs (finished in 2005), is a smaller passive use Park offering a respite and lunch place to observe the unfolding of a unique experiment intended to create a ‘functioning’ and contained natural landscape within a single city block. Three blocks further south is Jamison Square (finished in 2002), a year round gathering spot for locals, with a low broad fountain and plaza that draws children from around the region to play in summer.
The Fields Park was to be the one that offered opportunities for informal activities with the capacity to support small events. Unlike the other two it offers a large sunny lawn space. It is also the only one to feature a playground, a rare amenity downtown. Another goal was to provide the City’s first purpose built off leash dog area, separate from the main body of the Park to minimize conflicts with other users.
The Park was designed and built for a neighborhood with a quickly growing residential population housed in multi-story and tower structures that are still being added. There were a variety of reasons why this property sat vacant for a number of years while area developers and realtors were marketing their own properties with the Park as a selling feature, even before ground was broken. Part of the delay in its construction can be attributed to this sites history as an industrial brownfield, it’s contamination a result of its historical use by railroad and industry. While this did not limit Portland Park’s ability, in any meaningful way, in terms of intended use, it did have a huge impact on ‘how’ the site could be built on and the protections that were required by Oregon State DEQ to prevent the movement of contaminants offsite through groundwater movement. This single condition greatly impacted and complicated drainage issues and less directly, soil depth, both of which are vital to the success of any landscape.
The railroad tracks cut diagonally across its east and north. One of the biggest design features of the original concept, that was not built, was the ramp arcing around the north end that was to be the ‘launch pad’ for a foot/bicycle bridge that was to connect the Park with the Centennial Mill site along the Willamette and the future Riverfront Park, a bridge over topping the railroad tracks and Naito Pkwy, anchored to the Mill itself. This fell through because of a variety of political, design and funding issues that are still not resolved. The Mill site itself remains a bit of a moving target as far as its ultimate fate goes and is currently undergoing some demolition work that is removing the more ‘hazardous’ structures (Watching part of the removal process greatly saddened me as the massive timber framed structure was taken down shattering much of it, without attempt to salvage the old growth lumber.)
Many of my peers, still working for Parks, consider design review, on projects like this, vital to the work that they will inherit once any Park is completed and it becomes their responsibility to care for them. It was always one of our biggest frustrations. We would be arguing for design changes for horticultural/technical reasons and project managers would under value our concerns sometimes for aesthetic commitments made to other stakeholders, other times because the contracted Landscape Architects refused to consider our input and others??? We weren’t part of those discussions. From our perspective technical growing condition issues should take precedence over aesthetic design concerns as design options are nearly unlimited while horticulture concerns, like soil depth and drainage and even available labor, are more or less ‘fixed’ and must be addressed at some point or cost ‘us’ dearly later.
This site was originally part of a much larger system of wetlands and shallow lakes that were filled for industrial development and the railroad (One story mentions how soil was sluiced down from the hills to do this.) Tanner Creek was one of several streams that fed in. The original grade is some 20’ below the current surface grade. Its previous use resulted in the contamination of the soils here with a variety of pollutants. As I mentioned earlier this is a brownfield site. DEQ required that it be ‘hard capped’, that it allow no percolation of water down through the soil into the contaminated base soil which could potentially contaminate ground water and move it into the River. This required that the entire site effectively send excess rain and irrigation off site. Water can move into the soil where it may be taken up by roots and utilized by plants, but none may continue deeper. In our winter rain season, when we regionally receive most of out precipitation, deciduous plants are dormant and use no water. The water use of evergreens is greatly reduced due to air and soil temperatures that slow the plant’s growth processes. This effectively requires that most of our annual rainfall be moved off site.
Water moves down through the soil with the pull of gravity. It is slowed by the adhesive forces that tends to bind water to soil particles and the cohesive forces that hold water to water. Fine textured soils, with their large surface areas and smaller open pore space between particle, slows the movement of water down through the soil as does the compaction caused over time by pedestrian use. Soil is even more prone to compaction while it is wet and foot traffic is a serious source of compaction. Once the water percolates down through the topsoil, there is only one and a half to two feet of topsoil here on top of the hard capped base, it stops. It must now move sideways through the soil across a minimally sloping site. Gravity’s force is greatly limited in aiding this sideways flow especially since the same soil that slowed its downward movement is now working against its more sideways flow. It is effectively being slowed by a massive, somewhat porous dam. This topsoil will then tend to to be more saturated than what most plants require. Poor soil aeration will result in poor rooting and even rotting of those roots sent down more deeply during the summer growing season, assuming irrigation is not at a level that would create saturated conditions then too. The crew has worked hard to tune this system so that that doesn’t happen.
In a sense you could look at this entire site as a giant planter with a contained and limited soil volume. A large pot will have drain holes to quickly waste excess water. A large planter, especially one with a functionally sealed bottom, depends on soil depth to assure that plant crowns and roots have adequate soil aeration throughout the year. Eco-roof gardens have a similar problem but with very limited soil depth. Eco-roof systems recognize their water limitations and have some kind of interlocking grid that can support drainage flow across the bottom surface, below and separate from the ‘soil’, to drains or where it can be captured for reuse. These grid systems work in tandem with topsoils that encourage percolation but won’t silt up the grid and slow or clog drainage. I don’t know if anyone has every built such a system over a brownfield site but it does suggest an alternative, increase the soil depth and/or provide engineered soils and a drain system beneath. On the Director Square site, engineered less dense, soils were brought in and placed on top of the concrete roof of the underground parking structure for weight considerations. There the water percolates through and is able to sheet off on the concrete less inhibited because of the engineered soil which was a mineral material super heated and popped to expand its surface area and creating larger/coarser/less dense particles somewhat similar but denser than Pearlite. All of these would have greatly increased the project’s cost at The Fields. So, short of these alternatives, plant selections could have been made that were more in line with the soil conditions on site, conditions that varied, largely due to grade, in different areas.
Designers seemed to concede this point on the large central turf area and a surface drainage system was installed to carry much of this off. It should be noted that because most turf roots only in the top 6” of soil a saturated profile deeper would not harm it. The turf area does remain very wet through out the rain season.
I tried to make the architects aware of this huge limitation during design. My success was limited.
Plant Palette, Conflicts and an Alternate Path
It used to be commonly understood that tree roots went deep. It has been a long education process to get as many people as we have now to understand that most tree roots are in the top one and half feet of soil, yes their are notable exceptions particularly among Oaks and some drought tolerant woody plants. One might assume then that the topsoil here would be good for anchorage. That is not the case. The topsoil remains wet throughout the winter and is wetter as you go down. It does not drain like my relatively heavy fine Latourelle Loam at home. On similar sites I have plunged a shovel down into the top foot and hit standing water. As I said the soil is very slow to drain due to the hard cap. The rooting depth is therefore effectively reduced. This will effect the long term health and stability of the trees on this site.
When we were in this design process, horticulturists Park system wide, were being directed to look for what we could to achieve savings in landscape maintenance due to projected cuts in labor. One of the strategies is to plant xeric landscapes. While this for obvious reasons could not be implemented quickly, over time such an approach could make a real difference. The savings would come from lower water use, less maintenance in keeping irrigation systems operational and in having less weed removal/control work because we would not be watering all of the warm season weeds. My suggestions of a plant palette that would enable this went no where on this project.
We were given a design that did utilize a couple xeric plants but they were generally sharing beds with plants that required summer irrigation here to perform with vigor. For example were several big sweeps of Ceanothus g. h. ‘Yankee Point’. Most of these have failed. I also argued that if we were to plant a low Ceanothus here there were better choices than this one, a very popular plant in California landscapes, but little used here. I made several suggestions. These suggestions required changing out entire beds due to their conflicting requirements. There were other such conflicts one utilizing Festuca idahoense in an irrigated area and another planting Blue Oat Grass, Helictotrichon sempervirens next to Iris ensata. That planting still exists with both doing poorly and slowly dying out.
The Park forms a long arc along its north and east side where the built up grade drops quickly down to the Burlington Northern railroad tracks. There is an intermediate tier that’s paved, bounded for much of its length by cordons of Cornus s. ‘Kelseyi’ which actually, I admit, in winter looks nice. This area with its more steeply sloping beds, and consequent better surface drainage, seemed like the perfect situation for a large xeric West Coast landscape featuring some of our many beautiful west coast natives including some of the smaller Oaks and yes Ceanothus along with Arctostaphylos and many others, of which we have many beautiful ones to choose, underplanted in a meadow of mixed native grasses, including Festuca rubra commutatta and perennials. This idea was never discussed though I pressed for it repeatedly. Some natives were planted though they weren’t necessarily very good choices. Many of the Vine Maples planted here have died out. These typically occur in woodland conditions which this is not. A White form of Eastern Redbud was planted and is hanging in there. Some native Nutallii Dogwoods didn’t make it. Note that this and all other sites are receiving regular irrigation as are the weeds that have moved in. Again, the Ceanothus that were planted have mostly died. For me, though I like the design, in terms of layout and flow, I view the landscapes here as a lost opportunity with a very limited palette that offers limited seasonal interest. Perhaps, over time, staff can move them in a more xeric and sustainable direction.
I can envision this whole back bank planted in west coast natives with specimen such as Fremontodendron, Carpenteria, Garrya, select Ribes in addition to the Manzanita and Ceanothus I’ve already mentioned. The same theme could continue in many of the other beds especially those sweeping along the north sloping down to the fenced ‘dog area’. Some of it could be used to feature/display some of the particularly well adapted Mediterraneans like the many Cistus and Halimium. This group of plants have been successful on many other sites across the Portland area…just keep the summer water off.
There were other planting issues on this site that had to do with a particular plant’s use in mass that was/is problematic and others like the Fothergilla gardenii that had inadequate rooting space, poor drainage, too much reflected sun and probable conflicts with use given their more brittle structure. Or, the Japanese Forest Grass, Hakonechloa macro Aureola, that completely melts, having no winter structure to warn pedestrians away from the bed and the damage that such traffic brings. There will always be ‘quibbling’ in projects like this. What is more frustrating are the larger site condition problems that go unaddressed and the always present issue of maintenance and the pressure to become more efficient with landscapes that could have been more effectively designed to reduce the work load. Politics, internal and external, often drives decision making…at a cost.
Those of you who have gotten this far shouldn’t think that I was an unhappy employee that bears a grudge against his former employer. I simply have high expectations of Parks. Any organization tends toward conservative decision making and operation. They become more so as they increase in size. They tend to offer little internal support for innovation and creativity, despite what they may insist. These are viewed internally as ‘risky’ behaviors. It is always better to go with the old tried and true…even if it has demonstrably failed in the past, because it is the safe, ‘proven’, course of action. If one fails doing what one is told, what is conservative, while it may not be liked, the person will likely receive little ‘blowback’, because it is what most would have done. If, however, you push the edge, try something new or from beyond what is expected, and it ‘fails’, or someone important doesn’t like what you’ve done, there will be no one there to back you. I don’t know how much of a factor this was here at The Fields, but I do know that when a project costs several million dollars, nobody wants to look bad. When decision makers don’t know or care to understand the underlying problems and issues, it is difficult to deliver a quality product, to do your best, most responsible work.
Portland Parks could be a leader in terms of its plantings, educating the public in the process while providing beautiful landscapes. Today, too often, our big capital projects produce innovative built landscapes, structures, then adorn them with uninspired plantings that serve primarily as space fillers, repeating broad single species swaths and bands. Plantings, that in their simplicity, habit and requirements, often ignore growing conditions thus promising a need for a continual and demanding level of maintenance. There are pockets of inspired plantings around the Park system, generally done by horticultural staff over time. It is sad that collaboration between these two divisions is not the norm. While no one has all of the answers, horticulture attempts to understand the relationships of plants with both their place and each other. These relationships are real. The cost of ignoring them is real as well. Landscape design cannot just be a ‘graphic’ art put in service to meet human demands and needs. Without the science of horticulture, our ability to observe and learn, many of our plantings will fail. Horticulturally speaking this is not a sustainable design. It is not xeric. It requires way too many resource and labor inputs to be considered so. Sustainable landscapes are not so because people insist that they are. They are a definable entity. Missed opportunities all!