At this summer’s Chelsea Flower Show, Tony Woods, Director of Garden Club London, incorporated a Royal Horticultural Society trend into his award-winning Urban Flow Garden for Thames Water: a living wall, or vertical garden.

Woods created an edible living wall, inspiring gardeners to grow food in a small space while monitoring their water usage.

Woods said: “For edible walls, our system uses individual units that clip in and out of the main framework; you can replace plants and experiment with a range of evergreen and annual edibles.”

Vertical gardening 

Since Chelsea ended, many countries including the UK and the USA have faced prolonged heatwaves and drought conditions, creating added pressure for gardeners to restrict water usage whilst keeping plants healthy.

Living walls tend to require less water than similar ground-based displays, and the option of built-in hydroponic watering systems mean that potential hosepipe bans pose no threat. Whilst the living wall trend has flourished for several years for businesses and individuals, the Royal Horticultural Society’s approval and the persistent heatwave increase its appeal.

In contrast, Woods said: “Ground level planters are often specified by designers and architects with no form of watering, using crazy materials like stainless steel, which speeds the drought in tough conditions.” 

In her book, Grow a Living Wall, Chicago-based organic garden designer, author and social media influencer Shawna Coronado proves how accessible vertical gardening can be, whatever your space. Many of the living walls she creates are freestanding – the simplest are based on “layers of window boxes to hold 35-40 plants” – and affordable. 

Coronado recommends her own organic soil recipe to maximise efficiency: “One-third organic soil, one-third rotted manure, and one-third leaf mould or kitchen compost, and a scoopful of organic fertiliser when planting. This means watering twice a week, or every three days, not every day.”

Business sense

By 2015, living walls had become hugely popular for UK businesses, signposting their eco credentials and better assimilating their sites into the local area. There’s a certain amount of camouflage, even in built-up shopping streets or soulless retail parks, but less maintenance required than with flowerbeds or window boxes. 

The Village Bakery Baking Academy in Wrexham, Wales, is a perfect example: its 72m² LivePanel wall is a focal point, fed by a hydroponic rainwater system that reflects the bakery’s eco-friendly stance.

High street retailer Marks & Spencer was an early living wall adopter at branches like Cheshire Oaks, as part of its Plan A sustainability initiative in 2015. 

In the same year, living wall specialists ANS Global built the UK’s largest living wall, over 1000m², for the National Grid car park façade in Warwick, featuring strawberries and mentha. More recently, at the Postal Museum in London, a once-blank wall holds nearly 3,500 primarily evergreen plants, with five antique post-boxes interspersed. 

A vast living wall earns its keep at the Hotel Rubens at the Palace, in central London. Harriet Rowlinson, of the hotel, said: “The Rubens is kept cooler in summer and warmer in winter, lowering our carbon footprint, and it has encouraged birds, bees and butterflies, which was one of our main aims. We capture rainwater from the roof of the building in dedicated 10,000 litre storage tanks, which ultimately reduces urban flooding.”

Reducing pollution

It’s handy marketing fodder, too: a new Go Green hotel package, complete with vegan afternoon tea, imparts secrets of the living wall. Rowlinson said: “gardeners have to abseil down to reach the flowerbeds.”

The most tangible benefits of living walls are a reduction in air pollution and a habitat for bees, butterflies and other insects. Coronado noted they provide pollinator trails for migrating pollinators, “such as monarch butterflies”. 

Steve McIntyre, of ANS Global, knows pollution absorption rates vary by location, season, weather and plant varieties – he cited Hedera Helix as an efficient CO₂absorber – but biodiversity results are rapid:

“We recently built an 800m² wall in the Barbican, and already it’s attracting honey bees and butterflies. We also try to plant local species and bulbs that were there before construction.”

McIntyre emphasised that living walls help developers reach the green space targets attached to building regulations, especially in cities, where every inch on the ground comes at a premium. According to the Land Atlas of the UK, 98% of land in the City of London is built on. Unsurprisingly, the only way is up. 

International excellence 

Milan’s photogenic Bosco Verticale (or Vertical Forest), is a world-famous development. Its two plant-covered tower blocks designed by Boeri Studio won the RIBA Award for International Excellence in 2018.

With almost 17,000 plants and trees in just 1,500m² of ground space, Bosco Verticale comes highly praised by Biophilic Cities Journal, edited by Tim Beatley, Professor of Sustainable Communities at the University of Virginia and founder of the Biophilic Cities Network. 

External living walls are also popular at universities. ANS Global installed them in Cambridge, Edinburgh and York, whilst volunteers and students at the University of Texas at Austin built their own honeycomb design as a habitat for hummingbirds, lizards and owls.

The University of Ottawa’s six-storey indoor living wall biofilter, the largest of its kind in North America, reduces noise pollution and filters an incredible 80-85% of volatile compounds from the surrounding air; find smaller-scale begonia-studded walls at the University of Malmö, Sweden. 

Glasgow University’s new student accommodation at a former printworks, and Nottingham Trent’s University Hall extension, both set for completion in 2019, will feature living walls. 

Attainable and Sustainable

The American Farmland Trust reported losing 175 acres of farmland per hour to developers. 

Meanwhile, an indoor vertical farm at Princeton University tests the optimal ways to grow everything from kale and strawberries to basil and spearmint which, when successfully harnessed, will help combat the reduction in arable land for traditional farming. 

Whether growing food, flowers or an array of evergreens, a living wall is an attainable and sustainable way to support the environment, regardless of budget or scale.

This Author

Polly Allen is a journalist and travel blogger.