Growing green cities so people and nature can thrive

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This article was published 30/12/2022 (727 days ago), so information in it may no longer be current.

Growing a climate-resilient future hinges on finding nature-based solutions. With 68 percent of the world population projected to live in cities by 2050, sustainable innovations are needed to make cities greener and more livable so that people, communities, and nature can thrive.

An optimistic future was showcased this year at Floriade Expo 2022, a world horticultural exhibition that takes place in the Netherlands only once a decade. Featuring the theme “Growing Green Cities”, Floriade presented green solutions to fundamental challenges facing ever-expanding cities in this era of climate change.

The focus was on four sub-themes: green structures that make cities more attractive and sustainable, local food solutions, a healthy living environment, and sustainable energy solutions.

The six-month event (April 14 to October 9) welcomed more than 685,189 international visitors including horticulturists, landscape design professionals, urban planners, and garden enthusiasts from over 95 nationalities. Among the many visitors were Victor and Helen Lesser. Victor is manager of Red River Soils in Winnipeg and Helen worked as a teacher in her professional life. Both grew up on a farm. They have maintained a lifelong interest in growing healthy food in an urban environment and how crops are being adapted to our changing climate. Their visit to Floriade was an unforgettable green experience that provided them with insights on new technologies in horticulture including future plant-based products for more conscious living. Recently I sat down with Victor and Helen to learn about some of the nature-friendly solutions they saw at the world’s biggest horticultural exhibition.

Almere, a new city district on the outskirts of the Netherlands, was selected as the 2022 expo site. The 148-acre site was planted with 650 different tree species in alphabetical order as well as more than 180,000 perennials and thousands of shrubs, annuals, and flower bulbs. A more than 3km long ribbon of pollinator-friendly plants showed groupings of plants that are attractive to bees, butterflies, and other pollinating insects. One example of a bee-friendly plant grouping that Helen admired at Floriade included Perovskia Russian Sage, Pennisetum Fountain Grass, Phlomis Jerusalem Sage, and Persicaria bistorta, all of which can be grown in our Zone 3-4 climate.

The living library of plants provided visitors with design inspiration but also a future-focused message: plants are a food source for bees which are indispensable to helping plants grow and produce food. Eighty percent of the plants we eat depend on the bee for pollination.

“Bees were predominant throughout Floriade,” said Helen. There are an estimated 20,000 bees worldwide. “In the Netherlands, there are approximately 360 bee species,” said Victor. More than half of these are on the European red list of threatened species. In addition to a diversity of plant species, there were deluxe bee and insect hotels made from recycled materials and an imposing artwork at the entrance to Floriade called Beehold by artist Florentijn Hofman. Two giant figures (12 metres high) made of Corten steel were covered with 10,000 bees. Another sculpture showed a human embracing Mother Nature to underscore the message that cities need to welcome and protect nature.

At Floriade, Victor and Helen explored large community food gardens as well as space-saving options such as rooftop gardens at pavilions hosted by international participants. Roof gardens can be designed to harvest rainwater and provide more green space for biodiversity. The environmental and economic benefits of local food production in green cities of the future will contribute to greater sustainability but also to healthier living through a closer connection to the food we grow.

“Many of the pavilions at Floriade addressed the challenges of the changing climate and how cities can adapt,” said Helen. As city centres become hotter, trees and other greenery make life more bearable by filtering harmful substances from the air, cooling the air through their transpiration, and providing shade. In one example cooling shade was provided by a simple, natural trellis of trained tree branches supported by metal rods. There were also several examples of plants that are more readily adaptable to a changing climate. Amsonia Blue Star, for example, is a winter hardy perennial with sky blue flowers that is long lived and drought resistant. Roses, too, with their deep roots, hold up well in hot, dry summers. Green cities of the future will need to select tree species that have been bred to have greater drought tolerance, heat resistance, pest and disease resistance, and cold hardiness.

A 10,000 square meter greenhouse at Floriade was a living laboratory that demonstrated circular horticulture. Dutch greenhouse growers are world leaders in dealing with energy, water, and residual waste effectively and responsibly. Vic and Helen saw vertical farming methods but were also introduced to bio-based materials for food packaging and other innovative uses of plant material. Flower paper for example is made from 20 percent natural waste from growing flowers. How about diabetes tea made from the leftovers of crops identified as beneficial for diabetes patients? Or cricket protein, a future sustainable superfood that can be locally grown? Many plant and insect species offer potential nutritional benefits that are still being discovered — all the more reason that we must nurture nature.

Will we charge our phones someday with electricity from nature? The Bioo Lite technology uses houseplants, soil, and water to harness photosynthesis and generate electricity. Bioo panels use natural microorganisms to break down organic molecules in the soil and generate an electrical current in the process. It sounds incredible but it is technology that is working towards a more sustainable world.

Also on display at Floriade was the use of local raw materials for green construction as well as the use of recycled materials including fabric. The Natural Pavilion was almost entirely constructed from local biobased materials (made from substances derived from living organisms). Wood, for example, is a biobased material. In the Natural Pavilion, waste plant residues from the horticulture industry were bound together with mycelium (mushrooms) and used to build insulating wall panels. Helen and Victor were interested in the use of hemp to create a variety of building materials including walls and attractive flooring.

Recycled building materials were used in countless ways to reimagine the built environment, both indoors and outdoors. There were many examples of garden paths, fences, arbors, privacy screens, benches, and artwork made from repurposed materials to help reduce waste. But there was also innovative use of traditional materials such as bamboo. Helen and Victor were captivated by the beauty of the China Bamboo Garden which featured an arched bamboo bridge at its entrance.

Healthy cities will also need to incorporate quiet and relaxing places where inhabitants can rejuvenate. The spiritual garden at the Indian pavilion, which Helen and Victor visited, welcomed visitors to rest their body and soul.

Displays that highlighted the important role that healthy soil plays in making plant growth possible was of particular interest to Victor. Soil is a living organism that provides habitat for many animals and plants. Everything alive on earth uses soil which is one of the world’s most important natural resources.

Floriade can inspire everyone to play an active role in making our city greener.

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