Jefferson Circle lies at the south end of the downtown seawall in Tom McCall Waterfront Park helping to anchor what we always referred to as ‘the bowl’, site of the Dragon Boat races, July’s Blue’s Festival and the end of Summer Oregon Symphony performance.  The curving slope of the lawn that sweeps across the site assures attendees of a more clear view of the stages erected for big events.  Jefferson Circle and ‘5 Flags to the south, permanently ‘backup’ the temporary stages, while a third display bed, Columbia Circle, marks the main entry from downtown on the west.  All three beds share a common theme though they are by no means a mirror image of each other.

These three beds were part of Waterfront’s original design from the ’70’s.  Jefferson Circle an actual circle 40’ in diameter defined, like the others by a concrete bench that surrounds it.  Columbia is an ellipse stretched along its north/south axis, while 5 Flags is an ‘organic’ form with 5 ‘corners, each defined by a flag pole that for years displayed ours and a changing assortment of three other international flags.  Their plantings have changed over the years. I take responsibility for their current theme and most of their plantings.

Project History

I began the transformation at the close of the ’90’s after a series of budget reductions.  For several years leading up to this, annual display beds, with their more traditional bedding out style and twice a year change outs, were being reduced until all but a very few were cut entirely.  The rationale was that permanent plantings utilizing herbaceous perennials, would provide the floral display, but would require much less labor once they were installed.  Much of my initial experimentation either happened in Columbia Circle or in my home garden.  During the last couple of years, while I still had budget for annuals, I began a transition, utilizing a mix, including tender perennials and foliage/textural accent plants.  I began to play with how to get more interest with out depending on the bursts of annual color substituting Heuchera for Coleus, while retaining the bold foliage of Cannas that many of us had often used in larger annual displays (One negative side effect of this twice annual change over was that some plants, like our Cannas, were returned to the greenhouse each fall and, unintentionally provided easy transport for a particularly destructive virus, effectively eliminating its use as the virus seems persistent.)  Grasses might be thrown in for textural contrast and movement and I began experimenting with Bananas and Hedychiums as I still had access to Parks greenhouse space for wintering more tender plants over.  As time went by more of the plants I used became hardy perennials that evoked tropical forms and I looked more and more for varieties that relied on their foliage color and sheen to provide pops of color or to provide an effective foil for the flowering plants I was using.  Evergreen plants became central to the displays.  There would always be something to look at and these would occupy much of the space otherwise available to weeds…not to say that the necessity for weeding was eliminated.  Deciduous material would be interspersed or placed so that other material would draw the eye when it declined.

Jefferson Circle was not ever a display bed.  It contained a very simple planting of woody plants planted in a circular, bullseye, pattern with spring blooming Prunus padus, Bird Cherry, grouped in the center and underplanted with the evergreen Viburnum davidii.  Around it was a ring of Azalea ‘Hino Crimson’ and outside that Kinnickinnick.  For a couple weeks its flower display blazed in spring and then the whole planting fell into the roll of space filler.  The Bird Cherry trees were in decline for years a couple had been removed compromising the original design.  It was a low care/little show bed.  I’d work through it annually removing blackberries and pulling Oak seedlings from the near by Pin Oaks.  Weeds were a constant issue in the surrounding Kinnickinnick…that is, the Kinnickinnick that survived.  Located next to the ‘bench’ the soil was very compacted.  People sometimes stopped on nice days to eat their lunches here.  The circular bench suggested a ‘race track’ for younger children and they often used it as such sometimes veering on to the bed itself compacting it leaving the most compaction resistant weeds in their wake.

I petitioned to change out this bed several times over the years, offering a couple of differently themed ideas (the first was a xeric southern hemisphere idea that emphasized Australian plants).  They were shot down for budgetary issues.  (I did not have a planting budget.  Available money was in a pool that was drawn on for projects and emergencies across the Park system.)  Eventually I got approval in spite of my ‘NW Tropical’ theme which would again feature Palms, trees that some people in Parks felt were inappropriate in Waterfront Park.  We demo’ed everything except the perimeter bench, including the irrigation system, that came out with the tree roots.  The soil, which I knew was poorly drained and had planned on removing and replacing, was even worse than I had thought.  The entire bed was a giant bowl of clay, anerobic and stinky, much of it blue, thanks to its construction years ago and perfect for root rot.  We removed the top 1 1/2’ of soil and attempted to break up any layer beneath that with the backhoe (Here that was 70 cu.yds.).  The resulting surface was left rough to reduce drainage problems at the interface where a perched water table was possible.  Then we replaced the soil with a mix relatively low in organics (to minimize the settling that occurs as the organics break down) utilizing a sandy/loam base, pumice and compost.  It was delivered and placed by trucks utilizing a conveyor delivery system placing it accurately, minimizing grading and the resultant compaction.  I did the finish grade by hand with a heavy ‘drag’.  The final grade was a low dome, about two feet above the edge, with the highpoint north of center.  This would help better display the fore and middle ground for a viewer from the south end.

Irrigation System

At this point the guys installed an irrigation system that was designed for the planting.  Very often systems are installed on a grid or pattern that is too formulaic and ignores the bulk and massing of the plantings and so are inevitably blocked creating ‘shadows’ that remain too dry while the plants that do the  blocking cause water to ‘pool’ at their bases and  rot due to excessive water.  We also consciously chose nozzles with relatively short throws.  This allowed us to place them closer together than might be usual increasing the odds that dry/wet areas would be smaller and, minimizing the amount of over-spray lost on surrounding hard surface.  The nozzles are Hunter MP Rotators which produce less spray drift (loss) and more accurate deposition.  Each nozzle produces multiple ‘streams’ of different lengths that move across the proscribed arc.  There is an outside ring of heads just inside the ‘bench’ and an interior circle with one center head.  None of them are adjacent to larger plants and all are on tall pop-up risers.  Spaces between taller/more massive plants have heads located within them.  This was critical to a successful planting of plants that share similar water requirements.

Because there are always differences on the ground when it comes to planting, I didn’t follow the plan slavishly, but made adjustments to make sure the performance of the system was what I wanted.

Design & Theme

I settled on the ‘tropical’ theme.  I wanted the three beds, this one, Columbia and 5-Flags, to be consistent and related since all are in view of one another and stand as kind of a piece.  While I wouldn’t repeat all of the plants I would enough of them to have them read as related.  Some of my plant choices would repeat form, color or texture without being the same species, or sometimes even Genus, causing more astute visitors to pause and go, ‘Wait a minute!”  Many of the ground layer plants do reoccur in each bed like the Acorus, the Molinia and the Eucomis ‘Burgandy Sparkler’, while a closely related species may exist in only one.  There was a conscious attempt to create harmony through repetition while changing it up enough to assure interest.  All three contain Bananas though they aren’t the same.  Here I used the smaller growing, and hardy, Musella lasiocarpa which repeats in Columbia, but did not use the larger Musa sikkimensis, hardy in 5 Flags nor the Ensete ventricosum ‘Maurelii’, not hardy, in Columbia.  Palms occur in all three, though again they are different species.  There was also a conscious effort to create ‘matrix’ plantings where several species share a swath, create a more natural effect and to mimic nature filling more niches and hopefully reducing the opportunities for weeds.

When it came to laying out Jefferson Circle I was very aware that this bed can be walked around and that as the visitor moves around it I wanted it to be a continuous ‘reveal’ with changing ‘views’ as you walk.  Plants hidden and featured as you move, one in the background moving to the foreground and dominating as you circumnavigate the bed.  This is a very different landscape than a border which, in a sense, is more of a ‘two dimensional’ landscape as the viewer always looks from the front edge to the back which is itself not directly observable.  A landscape like this has more depth and is more exposed to the observer than a border.  The next step in complexity is a landscape that the viewer literally moves through and your experience becomes, more spatial and ‘active’, because in a sense you are part of this kind of landscape and determine how and what you see by your own movement and attention.  But, that’s for a later article.

At 40’ across and in a public Park, I wanted to limit hidden areas, so I needed to be careful with my massing.  Hidden areas very often attract those who are looking for a place to ‘stash’ their stuff, defined very broadly, as well as those who might be looking for a shielded place in which to ‘camp’.  This is a fact of life in the downtown area and very often, surprisingly, these shielded places may seem relatively open to most, but still serve this need for some.  So, it was important to keep sight lines open, which also helps with the irrigation coverage.

I developed my technique of using overlapping arcs or swaths of ground level plants while doing annual beds  rather than more simple geometric or patterned massing, common to ‘bedding out’, as I found it more interesting to look at.  I would rely on this extensively into which I would plant more strategically taller and specimen plants.  I tend toward informality and asymmetry, in design attempting to replicate the feel of ‘natural’ plantings where masses step up naturally to the trees and larger players in the landscape avoiding thickets.  (Jefferson Circle Click here for a PDF of the planting plan.  Jefferson Circle Note that it is not to scale.)

I didn’t design the ground layer and then ‘plug’ in the larger plants.  It all happened ‘organically’. I wanted visitors to have to ‘work’ at it a little to get the full experience, so I made the ‘back’ of the bed face those approaching along the Esplanade from the north their view blocked, somewhat by the mass of clumping bamboo with reveals along the edges to encourage them to walk around.  Those approaching from the west on the Esplanade come to the side again, not the primary view position.  The palms, magnolia and bamboo form an arc across the back that the other larger masses ‘play’ off of.  Another palm, T. wagnerianus, breaks this ‘rule’ and is somewhat separate in the ‘foreground’ toward the south.  The overlapping arcs of ground plantings work with them.  Though to some it may appear rather random, it is not, it is intentional.

 

 

When I designed this I did so on a north/south axis facing north.  The ‘landscape’ builds up from this ‘side’ giving it the longest view.  Most of the height and the bulk of the mass is around 2/3 of the way back, but it is loose and spread out in ‘front’ of the mass of Fargesia.  When you stand at the south end you look across the foreground with several of the low sweeping arcs curving towards you.  In the center, broadening in the distance, is a sweep of Molinia interspersed with several other South Africans, i.e., the Rhodocomoa with its finer soft texture rising and billowing above , while the strappy foliage interspersed while the flowers of the Agapanthus and Crinum float distinctively above, the Potentilla gellida scattered about, silvery and seeding into the open spaces.  Penstemon ‘Ruby’ frames it to the left contrasting with the grasses with its darker and heavier mass of its foliage while providing months of summer bloom color.  The Palms and Cordyline add to the exotic feel punctuated with the feather leafed Butia x Jubea cross center back.  This bi-generic hybrid is a cross of the two South American species Butia capitata and Jubea chilensis neither of which is consistently hardy across our region, so siting and size is critical.  Palms reach their ultimate cold hardiness only after they reach mature trunk diameter. (Please read this if you are curious how different Palms grow relative to the temperate trees most northern gardeners are used to.)  The Magnolia adds mass and of course its mass of white flowers in mid-spring.  The Crepe Myrtle echoes the bloom of the Penstemon.  Over time trees will add their height their foliage becoming a more dominant textural element.  Each should have space to better show off and, hopefully they will appear ‘natural’ and not monolithic.  That, at least, was my intention.

As you walk around counter-clockwise your foreground changes, the dark burgundy of the Eucomis contrasting with the lower vibrant yellow of the Acorus, a Parahebe substituting for the glaucous blue of the Melianthus used in Columbia circle.  Hibiscus x ‘Plum Crazy’ has disappeared, why (???) having once lent its tough as nails exotic feel.  I love the hybrids that are available now especially those from the Fleming Brothers.  Rotating further is the durable and floriferous Geranium ‘Rozanne’  and the species Gladiolus dalenii, another South African, out of which also pokes another Crinum.  Musella, lending its paddle shaped ‘banana’ leaves rides along behind with an Abutilon.  This abuts a sweep of Hellebores that washes beneath the Magnolia sharing space with Fuchsias. From here you see the long thin arc of Chinese Ground Orchid, Bletilla striata, that slices all of the way back through to where you began.  It divides the bed with its corrugated foliage and magenta blooms.  As you continue around your views are abruptly cut off by the ‘back’ of the Fargesia, with Hakonechloa and Iris x pacifica in the

foreground repeating the texture filled by the Acorus elsewhere.  Further on the Fargesia ends opening up select views back across the bed, but your eye has many other plants to rest on before.  A narrow arc of Molinia repeats hear before it continues with Acorus.  Bergenia lends its texture from out of which the soft rounded mass of Pittosporum tobira ‘Variegate’, Japanese Mock Orange, crowds its way in, providing its orange grove scent while it flowers, followed by a compact form of Crepe Myrtle, Lagerstroemia x ‘Zuni’, with its vibrant late summer blooming and later fall color.  Then, you catch back up to the Penstemon and soon again, your starting point.

The Plants

The table below contains my starting list of plants I developed as I worked on the theme and design.  Some of these were selected from the other existing beds around ‘The Bowl’ others were picked because of how they would fit.  When I’m laying-out plants sometimes it becomes obvious that some of the choices won’t have the space they need to fit in as I had imagined.   Some of these were used elsewhere.  A few have either died or have since become overgrown by more vigorous neighbors.  Other plants have since been added to take the place of the few failures, or because they seemed to belong, e.g., Musella lasiocarpa, the Chinese Yellow Flowered Banana; Parahebe perfoliata,which actually better fits the available space than the original Melianthus; Butia x Jubea; Rhodocoma capensis.

Jefferson Circle Plant List-2

 

 

 

 

 

 

 

 

 

 

 

Maintenance and Performance

The maintenance is about what you would expect.  None of these kinds of beds take care of themselves.  Some plants like the Geranium x ‘Ann Thomson’, a relatively vigorous plant, were over whelmed within the first three years by the Penstemon ‘Ruby’ it was interplanted with, mild winters allowing the Penstemon to grow unimpeded despite my cutting them back.  A ‘normal’ cold winter would normally freeze it down and reduce its overall vigor and size.  Other plants, like the Ligularia, I had originally spec’ed, L. ‘Britt Marie Crawford’ and for availability reasons, which varies widely seasonally, I purchased L. dentata ‘Midnight Lady’ instead.  It has been a little problematic in that it is a somewhat larger grower and successfully seeds in here adding to the maintenance and crowding out some of the other plants I used in a matrix.  The Gladiolus dalenii are beautiful and more subtle bloomers than most of the larger, more gaudy flowered hybrids and absolutely love the conditions here increasing quickly and, unfortunately, being subject to lodging, or falling over, when blooming begins.  The Black Mondo Grass is subject to being lost within the Acorus because of their differences in vigor. The Diascia and Veronica have met a similar fate as they too have succumbed under the growth of their neighbors.  The idea of some of these was to fill niches and thus help crowd out any weeds so losing them to more competitive bed mates is not altogether bad.  Two of the Trachycarpus wagnerianus were stollen early on, or they could have been tossed over the sea wall into the Willamette, a fate that has befallen other plants.  They were replaced.  The Geranium ‘Rozanne’ requires a hard summer cutting back to make it look more presentable late in the season and to encourage more bloom.  The Rhodocoma has been a pleasant surprise as it has survived and done quite well given all of the rain and the one hard winter we’ve had since its planting.  I could say the same for the Butia x Jubea, an unusual plant here in Portland.  I worried about theft, but not a lot as it was very heavy going in.  I also worried about losing it to cold, but it has proven itself and given that Palms gain in cold hardiness as their trunks grow up to mature size, serving to insulate their meristematic tissue in their bud at their base, I do less so over time.  It’s first winter had me erecting a ‘tent’ over it to keep moisture from entering down along the emerging shafts to the bud and possibly creating conditions for rot, but the local ‘homeless’ disappeared the tarp during the first night of heavy rain that winter.  After that I contented myself with packing loose leaves around the trunk for insulation.  The only other problem has been with the Magnolia.  Because it is evergreen and it is sited here next to the river it is exposed and subject to regular winds.  No matter how much it has been braced spring winds out of the south tip it northerly spoiling the vertical line of its trunk.

The Fargesias are a clumping type of bamboo so there is no need to contain it or constantly patrol for errant rhizomes.  These were relatively large going in, 10 gal+.  When we planted them Ian Conner directed me to plunge them deep, that lengths of ‘stem’ that were buried would root and better anchor the plant as the top growth pushed back and forth in the wind.  The individual plants have nearly joined into an unbroken hedge at this point and will continue to expand outward.  At some point someone will have to cut the rhizome back to contain its growth to protect plant neighbors…a job for a ‘bamboo slammer’ and several strong bodies.  This newest growth will be in the upper soil layers where conditions for growth are good, though clumpers do tend to be relatively deeply rooted if my experience with the related South American Chusqueas are any indication.

Most of the rest of the work is pretty routine and consistent with bed work in any herbaceous perennial bed.  I dead headed the Hellebores to limit their seeding in and also cut back their old growth prior to flowering so that it does not detract, though this is not strictly necessary.  I also dead head the Cannas to keep them looking neater through their blooming season.  The Molinia gets a winter trim, ideally being delayed until close to their rather late emergence date since they are’ warm season grasses.  This shortens the time that bare ground is exposed.  The Potentilla gellida got an occasional dead heading as well and maybe a trim to keep their summer foliage looking better, keeping in mind that their foliage is their primary contribution to the bed though many like the bright yellow flowers.  The Rhodocoma I didn’t cut down.  I individually removed dead stems as I had time.  Many evergreens, as they store reserve starches in their growth, don’t ‘appreciate’ being cut down.

And of course there is routine weeding.  Weeds like Oxalis entangling themselves in everything else is problematic.  I also had to keep an eye out for Equisetum, the common Scouring Rush.  Somehow it had found its way in, maybe via the off site purchased soil mix???   I didn’t use any pre-emergent herbicides to limit weed germination. My hope was that plants would fill in much of the space and a pre-emergent could limit the volunteering of desirable plants as well as weeds.  I used to go through this bed, and the others, once a week, weeding or using a scuffle hoe where I had room.  I would follow using a 4 tine cultivating hoe trying to minimize compaction from my own presence moving around the bed, which I would try to limit.  In this size of bed it is impossible to do all of this while reaching in from the edge.  Finally, some time during the dormant season, after most of the needed cleanup was done, we would apply a layer of compost.  At 1,250 sq.ft., 2″ of compost would require around a unit or 7.5 cu.yds. all of which was spread by hand as we didn’t have budgets that would allow it to be blown in annually on all of the beds.  Trucks, wheelbarrows, forks and scoop shovels.  Whether it was ourselves or a ‘crew’ of ‘volunteers’ was our only option.  I had over 3 acres, over 130,000 sq.ft. of bed, non-turf space, more than 100 times this one bed’s area, to manage annually in all the Downtown Parks in addition to other duties from tree pruning to design review.