From its green wall to its controlled climate, Assiniboine Park’s newest attraction is a gardener’s delight

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This article was published 23/12/2022 (636 days ago), so information in it may no longer be current.

An architectural achievement, The Leaf in Winnipeg’s historic Assiniboine Park has quickly become one of the most beautiful must-see horticultural attractions to visit in Canada since its recent opening earlier this month. The Leaf is an immersive experience for its many visitors, whether it is the exotic plants, summerlike environment, or the concepts of sustainability, biodiversity and conservation that are key features of this year-round indoor tropical garden.

One of the many awe-inspiring visuals at The Leaf is the green wall that is located in the light-filled Babs Asper Display House. A great source of inspiration for plant lovers, the green wall or vertical garden is a living work of art made possible through a donation by the Asper Foundation. The height of the green wall is 14 feet (4.2 metres) and its width is 82 feet (25 metres). More than 4,400 individual tropical plants in six-inch/15 cm pots are artfully arranged in a dramatic wave pattern. To learn more, I visited The Leaf recently and met with Wade Meisner, curator of horticulture at Assiniboine Park Conservancy, and Sara Wolowich Brown, communications co-ordinator.

The green wall at The Leaf is one of the largest interior green walls in Canada, said Meisner. It is the largest green wall installed in Manitoba by Air Strength Canada, an international award-winning interior landscaping business located in Winnipeg. The green wall consists of eight plant species, including Schefflera arboricola ‘Luseane’ (umbrella plant), Philodendron erubescens ‘Prince of Orange’, Dracaena deremensis ‘Lemon Surprise’, Ficus elastica ‘Ruby’, Ficus elastica ‘Burgundy’, Chlorophytum comosum (spider plant), Aeschynanthus radicans ‘Mona Lisa’ (lipstick plant), and Calathea lancifolia (prayer plant). The individual plant species with their unique textures, contrasting colours, and habits of growth create different depths for an almost three-dimensional look. Countless photos by visitors are taken in front of the green wall. “Even if you were to take a photo in black and white,” said Meisner, “you would still see the differences in textures, shapes, and sizes of the plant species.”

“All the species are common houseplants that you can grow in your own home,” said Meisner. The green wall is a remarkable opportunity for visitors to see the unique textures and growth habits of the different plants, all of which were sourced from Costa Farms in Florida, one of the largest horticultural growers in the world. The plants were started from plugs and grown in the greenhouses at Assiniboine Park.

The green wall has a bracket style design and is divided into different irrigation zones which deliver moisture directly to the root zones of the plants. The built-in irrigation system waters the plants once a week during the winter. Each of the potted plants is set into the wall on a slight angle. To give me a sense of how deep the lush top growth is, Meisner pulled out one of the plants. The soil was perfectly moist and the root tips a beautiful, healthy white.

The individual pots can be rotated as needed to ensure the plants are receiving an even amount of light for a more balanced look. Now, what does it take to rotate more than 4,000 plants by hand? I can’t begin to imagine but picture this: not only are the plants rotated to distribute light evenly and promote new growth, but the different plant species which have different growth rates are also pruned and shaped as needed so that they grow fuller and bushier. Leaf shine is another key element. It’s not just about esthetics. Dust on indoor plants can clog the stomata which are the pores on plant leaves and hinder light absorption. “We start early in the morning before visitors arrive,” says Meisner, “and spray the leaves using a hand-sprayer.” The foliage cleaner that staff use is called Pixie Sparkle.

The plants that make up the green wall are grown in the best possible conditions. The specialized roof on The Leaf suffuses the green wall with natural daylight. “In a typical office building, you would need artificial lighting to supplement the natural light, but this green wall does not have any artificial lighting,” said Meisner. An office environment would also have drier air, especially in winter. The humidity in the Babs Asper Display House where the green wall is located is maintained at 60 percent. “During the daytime the temperature is maintained at 20 degrees Celsius, and the nighttime temperature goes down to 18 or 16 degrees Celsius,” said Meisner. This is where it gets a bit complicated. The Display House is next to the Mediterranean Biome. “We have to think of the neighbouring plants in the Mediterranean Biome and the ideal temperatures that are best for the plants,” said Meisner. The humidity in the Hartley and Heather Richardson Tropical Biome, for example, is 90 percent. But the Display House where the green wall is located also features poinsettias which enjoy humidity around 60 percent and appreciate the same temperatures that are maintained for the green wall.

Compared to the former century-old conservatory which had light and temperature control issues, this new state-of-the-art building makes it much easier to provide plants with the environmental conditions they need. Adjustments will be needed, though, to the watering regimen supplied by the green wall as well as the ambient humidity levels once the summer months arrive when there will be greater light intensity and the possibility of leaf scorch depending on the plant variety. For this reason, the tropical plants selected for the living green wall are easy-to-grow houseplant species that tolerate a range of growing conditions.

Ficus rubber plants, for example, are quite resilient. ‘Burgundy’ rubber plant has dark purple-green leaves. ‘Ruby’ rubber plant has large leaves heavily variegated with pinkish-red, purple, and creamy white. The Schefflera umbrella plant does best in high light but is also tolerant of medium light. Schefflera ‘Luseane’ has small, dark green leaves. Gaze up towards the top of the green wall where Schefflera is planted in a broad sweep and gain a completely different perspective of its divided hand-like leaves compared to how the plant looks when it is viewed at eye level. Dracaena ‘Lemon Surprise’ features chartreuse and white pointed leaves that swirl from the centre of the plant in multiple layers. Spider plant with its arching leaves and baby plantlets is one of the most adaptable houseplants. Calathea, commonly known as the prayer plant or rattlesnake plant, has a brushstroke pattern and purple undersides. In the coming months, the green wall will take on a new, vivid colour when the flower buds of the ‘Mona Lisa’ lipstick plant (Aeschynanthus) open to fiery orange-red blossoms.

With the unique flexibility to switch out the potted plants in the green wall, how will its design evolve over time? For now, said Meisner, the emphasis is on the current selection of foliage plants but there will be opportunities in the future to reimagine the design with a new selection of plants, colour palettes, and patterns.

This holiday season, The Leaf is the balmiest place to be. Leave your coat at the door — it’s warm inside.

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