How many people know that Wellington is considered one of the 12 biophilic cities in the world and is part of the International Biophilic Cities program sharing knowledge about how to create great cities? As far as I can tell, few people are aware of this, and yet it is something the rest of the world is greatly interested in.

In 2013, Hanging Gardens was asked to put up a vertical garden for the Wellington City Council “Biophilic Strategy Programme”. The site chosen was a nasty, wind ravaged and deeply shaded alley, next to the Opera House and no one else would touch it.

We did not see any issue with a garden in this site, as our gorgeous natives can deal with far worse conditions! We worked with the wonderful team at the Porirua City Council nursery, Siever’s Grove, and selected locally sourced plants. The garden went up and as far as we know, has never had any maintenance since then.

We still get reports on how the garden is doing and once someone from the Council phoned to ask us if the plants were likely to fall out and kill someone, as they had grown so well, but other than that, the garden just does its thing.

A few months back, we had a call from another company which was asked to replace a wall done at the Victoria University. This garden had failed and the client wanted one “that performed like the one in the Opera House lane”. Naturally we were delighted to oblige and this will be installed in the next couple of weeks, with the help of our friends at Siever’s Grove nursery.

So why do some gardens get so big while others fail?

We believe the secret is in the soil. many of our native plants have evolved over millions of years to grow in little pockets of soil. They need room to grow and they thrive in symbiotic relationship with the bacteria in the soil or leaf litter.

At Hanging Gardens, we believe in working with nature. Our gardens are based upon our unique, botanical felt pockets which hold the soil and allow for a plant density of 9-15 plants per square meter. (And yes, they show some gaps to start with, but this is not unattractive.) This is a natural approach to creating great habitats for flora and fauna, and this, we believe, is the reason for the success of our gardens.

Other systems, which use inert mediums or unnatural habitats for the plant roots, work on a plant density of up to 120 plants per square meter. This may look great to start with, but it is unsustainable for plants over the longer term.

So no matter what the location, selecting the appropriate plants and giving them a little pocket of soil, is just about all it takes to replicate a natural environment that performs over time. We look forward to helping Wellington continue to show the world how vertical gardens contribute to the biophilic status of the city and hope that many more gardens will go up the walls in the future.

Leigh Nicholson