Crop Circles and Urban Meadows

[Above: structures and asphalt were recently removed from this lot for planned, yet subsequently stalled construction of park space.  Exploring this interim surface, circular seedings of perennial grasses and forbs were implanted into the rubble.  These ‘crop circles’ emerged as whimsical garden tropes while functioning as test plots meant to interact with weeds spontaneously colonizing the new ground]

[Above: the introduced vegetation had to contend with a compacted, sterile medium and maintenance regimes aimed at taming it.  Below: over time ruderal plants continued to spontaneously colonize the field in tandem with the shifting territory of the crop circles –their withering and extending –forming a contested space between the ‘introduced’ species and the ‘indigenous’ weeds.]

[Above and below:  crop circles in the immediately adjacent, and more advanced meadow.  Demolition had occurred several years earlier and ruderal succession is notably further along.  Here the ground surface of the crop circles were ripped and overturned before being seeded.  The green circles are composed of horticulturally-engineered cultivars of rye grass.  The tan-magenta circles are native meadow mixes, which abruptly died in the foreign medium after germination.  Weeds and the engineered species proved far more adaptable to the foreign conditions of the urban meadow.]

[Diagram of seeding trials over time (left to right). Far left: initial seeding of crop circles on the vacant surface.  Middle: experimental plots expand or die back in response to the site.  Disposable cover crops and failed seed mixes are reseeded while spontaneous ruderal species continue to populate the field.  Right: as disposable crops of heavily seeded and reseeded patches die out, they contribute organic matter and structure to the relatively sterile ground, thus accelerating the creation of soil.  Tertiary seeding regimes (rectangular shapes) are placed to intersect with the original crop circles, forming seeding palimpsests, or successional Venn diagrams.  Areas of overlap will test how successive waves of seeding respond to different seeding regimes preceding them.  As soil conditions improve, a wider palette of plants can be introduced to the hybrid meadow for increased habitat value or other functions.]

[Heavily seeded circles of vegetation expire, turn to shades of tan and brown as seasons shift, and readily become in-situ compost above and below ground.  In parallel, the cultural garden trope morphs and forms new associations to its public cemetery surroundings; remnants and burial markers similar to adjacent headstones seen in the background.]

This particular experiment is still in its early stages, having been in process for a little over a year.  It has encountering failures and some surprising successes; one of our ongoing dialogues with derelict lots. The method plays with field acceleration through selective pulses of seed dispersals, making pragmatic use of their variety, availability, low-cost, portability and generative capacity.  Here in the Willamette valley, we have ready access to more horticultural varieties of manufactured seeds than perhaps anywhere else in the country, as we grow and deliver most of it to the rest of the country.

In instances like these, the experimentation occurs in both the constructed ground – the found, remnant mediums of demolition rubble, broken asphalt, etc. –  and placing those mediums in new relationships with varieties of constructed organisms engineered to do particular ‘productive’ things.  Similarly, I recently had the opportunity to pick up Peter del Tredici’s Wild Urban Plants of the Northeast.  Beyond being a great field guide to weedy plants (most of the weeds the author encounters on the east coast are the same as we have here), it also provides a more thorough interpretation of what weeds are from an urban ecology perspective, as well as some prescriptions (tantalizingly brief) for landscaping with spontaneous urban vegetation.  Similar to what we are attempting to do here, Tredici states that “the basic idea behind the cosmopolitan urban meadow is to select an assemblage of plants that will grow well on typical urban soil, create an aesthetically pleasing urban meadow on vacant land, and remain in place until a more permanent use for the land is developed. ”

Tredici prescribes the planting of select ‘weeds’ themselves (rather than the horticultural/agronomic freaks we are working with) because they are so well-suited to these conditions and require almost no maintenance to provide a range of under-appreciated services.  He inverts the typical native – non native debate: weeds are naturally adapted to these denatured conditions and their presence isn’t the real problem per se (although it also is); its more the ubiquitous altered conditions and disturbance regimes that we perpetuate, for which they are merely an unavoidable symptom.  Similar to the observations from the experiments above, their presence is ‘natural’ in the causal way we tend to use that word.  The urban meadow preparation methods Tredici describes are different from what we are experimenting with here (a bit more intensive in terms of amending the medium, but likely to produce results more quickly – methods we hope to also try). But the underlying intent is the same:  how to engage aesthetics, function and manufactured ecologies of weeds on idle-interim surfaces found throughout cities, without fully taming them.

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