Somewhere in San Francisco

Pollinator Friendly Lawns

You could say that I am not a big fan of lawns. Oh sure, I love to play a game of football or walk the dogs on some green turf. But lawns are the landscape default mode for most human habitat--college campuses, city parks, subdivisions, and businesses. You will find lawns even where they aren't really necessary, mostly because we feel compelled to control nature. Rachel Carson once wrote that "the control of nature is a phrase conceived in arrogance, born of the Neanderthal age of biology and the convenience of man." She's right, we cannot control nature without feeling its aftereffects. 

I have removed significant amounts of turf from very place that I have ever lived and gardened upon. That goes for most projects that I have worked on as well. At my previous home on the Gulf Coast, I drowned 60% of the existing lawn area by deeply burying it in pine needles from the 17 mature longleaf pines on my property. To build my beds, I simply raked paths in the pine straw. Within a few short years I had effectively killed the lawn underneath and even began to build an organic layer. All that I had to do was to plant directly into the pine straw. I reduced two and half hours of weekly mowing and edging to about thirty-five minutes of sweat. 

But I noticed in lawn that I did keep, a wealth of native and exotic wildflowers grew in it. And if it was too wet to mow in some weeks, I had a healthy and beautiful wildflower garden that resulted. I stopped mowing when the lyre leaf sage came into bloom (Salvia lyrata), and mowed when their seed dispersed, ensuring new blooms and plants for the following year. I even did a species count once and identified around 15 species in a square meter. Not bad in biodiversity terms. 

Some herbaceous plants will grow quite well with regular mowings of the lawn. Below is a list of species that are turf companions, will bloom and benefit the pollinators in your neighborhood.

Native species of grass companions:

• Blue eyed grasses (Sisyrinchium, several species) not a true grass but a member of the iris family, with pretty blue flowers
• Cinquefoils, (Potentilla). Similar to wild strawberries
• Wild strawberries (Fragaria, several species). The five lobed leaves of this and those of cinquefoils are very similar in appearance
• Yellow violets (Viola pennsylvanica). A few other species of violets are also native
• Spring beauties (Claytonia spp.)
• Wild geraniums, crane’s-bills (Geranium spp.)
• Azure bluets (Houstonia caerulea)
• Speedwells (Veronica), with several species, some native others introduced
• Wood sorrel (Oxalis acetosella), used as ground cover by some gardeners
• Smartweeds, knotweeds, many species in the genus Polygonum; some are small enough to do well in lawns. Some species are native and others introduced
• Asters (Symphyotrichum spp.) are great in the fall. Some grow rather tall, better for a meadow than a lawn; but if mowed not too frequently, they can do well and bloom heavily inviting many species of pollinators
• Chickweeds include two genera: Cerastium and Stellaria. They are also known by several other common names; some species, such as field chickweed, (Cerastium arvense) and star chickweed (Stellaria pubera), are native. They are small enough to do well in lawns

Non-native species of grass companions:

• Clover, (white clover, Trifolium repens) a European plant very well established in the United States. Grass-seed mixes used to include it. It is highly beneficial because it fixes nitrogen, thus enriching the soil. Newly developed herbicides killed clover, along with the undesirable broad-leaved weeds, so it was declared a weed by the gardening industry and removed from grass-seed mixes. A few species of clover are native to some regions of North America and it may be possible to grow them as grass companions
• Creeping thyme (Thymus serpyllum) has sometimes been used as ground cover
• Chickweed, also called starweed, winterweed, satin flower or tongue grass (Stellaria media), is not native. Its seeds are eaten by some birds, hence the name chickweed. It has very small, star shaped flowers
• Gill over the ground, or ground ivy (Glechoma hederacea), is rather pretty but it tends to become invasive
• Dandelion (Taraxacum officinale) is among the non-native invasives which you may not want to see around but it is so widespread that perhaps we can’t do much about it

Thanks to the above great grass companion list by BY BEATRIZ MOISSET. You can find her article at http://nativeplantwildlifegarden.com/pollinator-friendly-lawns/

Blogger Feature: Marginal Nature and Urban Wastelands

Check out this interesting blog on marginal nature. Its author, Kevin Anderson, states in the description: "marginal nature is found in urban wastelands such as neglected creeks, wastewater treatment ponds, vacant lots, road and rail waysides, brownfields, fencerows, dumps, and alleyways. What emerges in this wastespace is the unintended product of human activity and nature's unflagging expressiveness, which I call Marginal Nature." Kevin M. Anderson is a geographer and philosopher who is the coordinator of the AWU - Center for Environmental Research in Austin, Texas. Check out his blog at http://marginalnature.blogspot.com/

Book Review: Drosscape by Alan Berger

Author Alan Berger, professor of urban design at MIT, takes an in-depth look at the leftover pieces of land in urban centers. Borrowed from Lars Lerup’s essay entitled “Stim & Dross,” dross refers to waste landscapes, the leftovers between developed lands. Berger calls this the in-between’s of a city’s urban fabric. He makes the case that urban lands are in constant flux and that urban sprawl is rampant, and will continue to do so even with the best of urban planning intentions. As business move out of the developed cores, obsolete lands form in the center, which spreads outward like a cancer. Lerup proposes that urban areas could intentionally provide a mix of developed and leftover lands, a hybridization of use and non-use. This is a refreshing concept and flies in the face of current urban planning, which seeks to place priority on infilling vacant lands (brownfields and greyfields) for new development. The idea is that infill curbs sprawl and perhaps maintain more forests and fields at the city edges. One problem with this idea is that unless there is an urban growth boundary (such as found in Portland, OR), infill doesn’t seem to hinder eventual sprawl. Something will build there eventually. The other, more insidious aspect, is that with an attitude of continual infill, few open green spaces are left within the city. Albert Pope, professor of architecture at Rice University, argues against filling in these voids. Continual infill results in communities like Roseville, Michigan; the city of my childhood that had no parks or open areas (other than athletic fields) within walking or biking distance—just wall to wall hardscape. Of course now with the demise of Detroit, the industrial edges of the city are becoming forested once again. Hopefully they will keep a few of these before they renew, redevelop, and infill. Berger takes a look at 10 urbanized areas in the book, ranging from Atlanta to Phoenix, and reveals the drosscapes found there, both in map form and aerial photos. Drosscapes presents a graphically intriguing overview of leftover lands in cities within an urban planning context. It provides some new terms for places that have no words—such as “demalling” (obsolete shopping mall areas) and “terrain vague” (economically failing areas). It also looks at cities at the metascale, providing a big picture view. But it also offers incentive to the architect, designer, or landscape architect at the project scale, to design “empty areas” within the property footprint—whether these be forested or reclaimed lands that remain unbuilt, or unpurposeful. What could these look like?

Wildlife Types Vary According to Urban Density

Cities tend to have similar wildlife types and habitats, no matter where you may live in the world. That’s why Norway rats, cockroaches, and pigeons are everywhere—they follow in our footsteps. But research has shown that native plants and wildlife are plentiful at the city edges but decrease as they get closer to downtown. Michael McKinney from the University of Tennessee sums this up nicely in his 2006 article in the journal of Biological Conservation. Entitled Urbanization as a major cause of biotic homogenization, McKinney collects a wealth of data from around the world, as well as mining existing data sets, on how wildlife and plants respond to urban density. He observes that cities tend to share similar wildlife types and habitat structures and thus are very homogenized (similar) and homeostatic (unchanging). Whereas city edges that abut natural conditions tend to be more varied and dynamic thus providing more habitat types and food for urbanophobes (wildlife that do not like being around humans and their environments). Based on the information and references McKinney provides in his article, I observed that there are three primary and distinct urban habitat zones—periurban, suburban, and urban. Or, in other words, the farther that one gets from the wildland interface and the denser the development, that wildlife and habitats change. This may be useful information to landscape architects or planners that seek to provide green spaces for wildlife habitat in densely urban areas.  The types of wildlife that you hope to attract probably depends upon the scale of habitat that you are designing and how they will arrive from native populations. The following graphic that I developed summarizes the general wildlife and habitat characteristics as provided by McKinney (2006):

It’s been noted that urban areas may exhibit a high diversity of plants and animals, sometimes more than the adjoining countryside. But while the numbers may be high due to more planted exotic vegetation species; the quality of the habitats, food, and ecosystem services may actually be more impoverished as compared to a native landscape. This is mostly due to the use of plants (native or exotic) with a reduced gene pool and a lack of resilience. McKinney notes that using local native plant species in urban areas enriches not only the urban genepool, but creates a much richer environment for people.

Somewhere in Starkville

Melbourne, Australia: The City Within a Forest

The “City of Melbourne is driving an ecosystem-based climate adaptation program with a goal to double urban forest canopy cover and increase permeability to cool the city’s summertime temperatures by 4°C. This presentation video reflects on how the City of Melbourne is implementing a transformative program of works to create climate resilient urban landscapes that support healthy ecosystems and healthy communities. In particular, it focuses on the role of citizen participation and transparency in co-designing plans to turn the world’s most liveable city into a city within a forest.” Learn more about this project in a video presentation by Yvonne Lynch, City of Melbourne Urban Ecology and Forest team, at the Biophilic Cities Project Youtube channel at https://www.youtube.com/watch?v=W6tpNXXUmow  (40 minutes).