Tuesday, February 21, 2012

Dead Living Wall - Why? Case Example, Whole Foods, Jacksonville, Florida

During our last post we looked at a marvelous grid system creating the structure for numerous living walls covering the Whole Foods grocery store in Jacksonville.  Although shiny and stainless steel living wall mechanical support system was superb in construction and installation, the plants have decided over the past three years or so that they do not like something about the entire design and are refusing to do much except die or just barely survive.  Today we will discuss why these plants are not thriving and tomorrow we will look at recommendations for plant replacement.

Over the years we've come to understand Living Walls to be one of the most significant challenges for the urban core landscape designer, and for many reasons.

Living walls, unlike horizontal ground level landscapes are subject to exponential more desiccating exposure from winds because they exist on a vertical plane without typical ground level wind-breaks.  Additionally, the same holds true for sunlight exposure.  Both sunlight and wind can rob the living wall plants of much needed water, thereby breaking the Calvin cycle of photosynthesis and denying the plants life sustaining nutrients.

Last year we posted an article on why we consider wind and light to be the two top design factors for green roofs and living walls.

Too much or not enough light dooms a living wall plant through impact on photosynthesis, yet even though there was concern raised about the quantity of available light under the store's front area, the southern facing living wall, with plenty of light exposure, was not growing either.  Our model pointed to issues other than available daylighting.

Wind too, though usually a primary design variable, did not seem to be impacting the living wall as we first thought it may.  Our hand held anemometer, though granted was used over a limited period of time, did not record any wind speeds of greater than one meter per second and in fact showed the building itself was acting as a sufficient windbreak.

However there are other factors to consider when analyzing the Whole Foods dead living wall.  A secondary design variable we often look for is the presence of alleloism and adjacent allelopathic plants, such as cypress.

We did not find much to suggest allelopathic issues on the site, though allelopathism can sometimes be overlooked.  Chemicals produced in the leaves of some plants can act just like herbicides, preventing other plants from growing.  Sometimes allelopathic acting leaves may accumulate on a roof and act as a herbicidal drench during rain as water fills gutters and downspouts.

There was a more interesting issue presenting itself though.  Though living walls have been grown successfully around limerock outcroppings and stone walls, the correct combination of soil amendments, plant selection, light, available water and wind breaks must be present for the growing successes a landscape designer seeks.

The Whole Foods living wall systems were constructed directly over an old, demolished commercial building foundation and though some organic matter has been added by the landscape installer, the urban soil composition on site is obviously full of concrete.

Concrete contributes to a high pH.  High pH restricts available nutrients and itself has a negative impact on plant root's ability to absorb water.  However some plants are very well adapted to growing in these higher pH conditions.  Yet many are not.

Living walls can successfully be created even in rock & concrete filled areas

Plants and concrete can exist side by side with the right design
The attitude of 'lets pour a couple bags of potting soil into a whole around the plant's roots' just doesn't work though.  Many times landscape installers take the shortcut, placing their unreasonable hopes for a lush wall on the struggling plant.

Understanding urban soils, concrete and how to amend these soils for the right plants comes with years of experience.

Though we are all aware of cost control, long term dead living walls installed without consideration to matching plants to all growing variables do not provide the cost benefit originally proposed during the architectural and landscape design.

Whole foods has many options available to produce magnificent living walls for the Jacksonville store.

In sync with cradle to cradle concepts, Whole Foods could, once the right plants were installed in the correctly amended soils for the light levels and wind exposures, use a compost barrel in back of their store - or as an educational part of their landscape - and use produce destined for the landfill to begin building wonderful planter soils.  Solutions do not have to be messy or expensive.  Living walls create habitat for Florida green tree frogs and Florida anoles.  Biodiversity acts as integrated pest management for fly and bug control.

Why are Whole Foods living walls dying?

Wrong plants for the urban soils.  Urban soils needing specific micronutrients and other factors.

Next post will discuss specific recommendations to create a lush living wall.

Friday, February 3, 2012

An Expensive Florida Living Wall's Death. Why?

Florida boasts several wonderful Whole Food stores and I enjoy shopping within, relishing the samples of exotically delicious cheeses, thin sliced blood oranges and store-made salsa.

After yesterday's visit I chose a chair on the marketplace's front patio, affording me an opportunity to sit and think about why their beautiful and very expensive Florida Living Wall trellis system and plantings had miserably failed.

Whole Foods' dead Florida Living Wall

The living wall failure was nothing new.  Ever since the store's construction and opening in 2008-2009 I had watched in fascination at the shiny stainless cabling and support brackets, hoping to see a lush, tropical wall of living, breathing vegetation established, one providing habitat for Florida's native anoles and tree frogs (themselves wonderful pest-management strategies), cleaning stormwater, fixing CO2, pumping fresh oxygen into the air, providing a much needed Sense of Place in an otherwise increasingly Urban Concrete Jungle and more.

However, despite the expensive trellising, cabling and other stainless attachement hardware, the wall supported little else but brown, dried and dead plants and vines.

Florida Living Walls must be designed with appropriate criteria to ensure survival

Such a shame because the trellising highlights the main entrance.  Customers must walk past the dead vines and plants to enter the store.  Though I am not a high-powered marketing expert I can easily recognize a sense of failure, brown and disappointment that most people would subconsciously acknowledge when walking past the dead vines and plants.

What went wrong?  Who did the install and design?  

Surely the trellis system was expensive enough and fabricated from a high quality material.

Why, after numerous attempts at plantings by staff and contractors are the living walls still dead?

Invasive Nandina is hiding the failed Florida Living Wall, Whole Foods, Jacksonville, Florida
These are all questions a good living wall designer must ask themselves long before final project specifications and ultimate installation.

Certainly the issue is not one of plants and constructed buildings being fundamentally unable to coexist.  As we read in yesterday's post 'Green Roof Sleuthing' shows us just how compatible plants and structures actually are and in fact, buildings would soon be overgrown with plants if left unattended.

Some landscape designers I've talked to scratch their heads, wondering why the plants they typically specify and use in horizontal landscapes just dont work in Living Wall or Green Roof applications.

And there are many very important differences.

I've always said Living Walls are magnitudes times more difficult to design and successfully keep looking good in the long term.

So the designer needs to be on his or her game up front.  All important design criteria must be analyzed and recognized when specifying all the components of a Florida Living Wall System.

As I rested on the front patio of the Whole Foods Marketplace in Jacksonville and examined the Living Wall design, the issues became obvious.  The opportunity for a magnificent Florida Living Wall, one that would greet customers with lush texture, color and scents was there.  Some of the components though were missing or ill-installed.

So what is the answer to the Whole Foods' dead Living Wall in Jacksonville?

Tomorrow's post will discuss what I perceive mut be done to produce the Florida Living Wall, one that would greet customers with lush texture, color and scents and truly welcome and invite money-spending clients inside.

Thursday, February 2, 2012

Green Roof Plant Sleuthing! Understanding why some plants grow better on roofs.

I call the process - 'Green Roof Plant Sleuthing'!

Simply put, Mother Nature is the best teacher for what grows well on a wall or on a roof in hot, dry, arid and monsoon-like climates.

Nature created green roofs cool buildings and provide habitat

When students of Green Roof technology ask me for recommendations concerning plants and green roofs, the first task I suggest is always to do a little Urban Sleuthing.  Walk around downtown, watching your step and keeping an eye out for traffic yet looking up to the city roofs, gutters and tops  of building structures.

Most are amazed to see just how many plants actually grow out of cracks, with minimal soil and survive the typical harsh conditions of a rooftop.

Green Roof Sleuthing is fun & educational!

Excitingly, these naturalized plants can produce a full and flush growth habit, offering an almost tropical look to the roof.

Walking through St. Augustine the other day I ran across many nature inspired green roofs, all quite beautiful and providing habitat, cleaning stormwater, cooling the buildings and pumping fresh oxygen back into the air.

Hidden among the lush resurrection fern were also many interesting smaller ferns, vines and other plant species.

MetroVerde finds many new Green Roof Plants through Florida Green Roof Sleuthing

So next time you wonder about the type of plants to use on your next green roof project, be sure to consult with your local nurseries and growers but also do not forget to do some Green Roof sleuthing yourself.   Take a walk through the downtown and look up.

Chances are you may never use those plants you see growing out of the buildings but then again, knowledge is power, especially when working with plants on roofs!