Roof Top Air Plant Gardens: Lloyd Godman

Roof Top Air Plant Gardens: Lloyd Godman

air plants by loyd godmanPhoto: The Melbourne Age: supplied by Lloyd Godman

Air plants (Tillandasi) are growing on the very top of a 297 meter building in Melbourne Australia! The Eureka Tower ! The plants have been installed by environmental artist Lloyd Godman.

The sculptural plants, have been an indoor decorating hit in the UK, USA and Australia over the last 5 years (air plants and interiors ).

 DSC_5661Photo: gardenbeet.com

 

air plants
Garden Design Blog

Photo: floragrubb.com

Why would you put air plants on the roof top?

The plants grow at night and provide a possible solution to reducing pollution during the evening peak. Air plants are also a cheaper solution than soil grown plants.

Roof Gardens

Roof gardens are becoming a mainstream solution to overcome environmental issues such as air pollution and urban heating. The French National Assembly  ruled last week that all new commercial developments in the city centre of Paris must be partially covered in roof gardens (Green Roofs for Paris) . As this environmental mitigation trend continues there is likely to be an increasing demand for techniques to deliver cost effective roof garden solutions .

Roof gardens are expensive. Partly because they are maintenance intensive. Partly because soil can add considerable weight to the roof structure. Airplants can minimise these impacts as they require no soil and no direct watering.

Can Air Plants Survive on Roofs?

Godman is conducting an interesting test in Melbourne, Australia. Air plants are sometimes considered to be rather temperamental in cold temperatures.  They originate from the warmer climates of Central and South America. It is pleasing to hear that the plants have not only lived but they have flowered too. Godman advised that he is trialling only two of the more robust air plants:  Tillandasi bergeri and Tillandasi Houston (Houston is a hybrid – a cross between T. stricta and T. recurvifolia ).

Godman has been working with Phillip Johnson Landscapes and together they have devised three key issues variables that will influence the success of growing airplants on your roof.  First is aspect, second is the species and third variable is acclimatisation.

We asked Godman a few questions post publication. The responses are below

VGO –  Can air plants reduce pollution in cities to the same level that trees can? 
LG – *The air plants have a very low metabolism and grow slowly so while they take in carbon they do it very slowly –  however the more plants the great the effect – 1 plant would have a very small effect – in ten years one plant might multiply to 1,000 plants in another ten years this would be 1,000,000 plants so the effect is exponential – 1,000,000 times the carbon
* the other thing these plants do that few trees do is uptake heavy metals through their leaves from the atmosphere, they have been used as biomonitors to monitor heavy metal levels on highways and cities
* because they use a CAM cycle to grow they photosynthesis at night so they take in carbon and release oxygen in darkness –  most plants are asleep at night  –  so they clean the air at night and compliment the cleaning process that trees have during the day.
VGO – Do you think air plants may become a viable roof top solution for new developers and retro fitters  looking to ‘green’ their buildings?
LG – *Because of the very low weight – about 3kg per sm compared to vertical gardens and roof tops which run about 50 -70 kg per sm and the fact there is NO watering system needed they are perfect for retrofitting –  the screens that hold the plants need not sit against the wall but can be suspended out from the facade  by 1m or even more  –  so they can act as a weather shield to protect the building rather than risk water and nutrients like phosphates and nitrates that are used in most reticulated systems reaching the structure of the building . They can also be set up as movable screens that move from the facade across windows for heat mitigation on hot days  –  we have even done some work on screens of plants that can move up and down a building driven by the tide.  The plants are salt tolerant so will work in coastal situations. For roof top gardens they could be used to create an over head sun screen that breaks intense sun and creates dappled light patterns where other plants that grow on the roof surface can benefit. So the applications are huge.
VGO – What aspect is best?
LG –  In  terms of aspect I have various species growing in almost every aspect you can imagine –  fully north west sun  –  east  – south  –  shade –  some in sheltered positions where they receive sun but virtually no rain other where they get the full force of the weather.