The Largest Living Wall-a Year Later

“It’s doing well,” says Lorrie Baird, senior gardener at Longwood. “There are a few plants that are being a little feisty with us, but overall it’s doing really well.”

The concept of the wall was created by British landscape architect Kim Wilkie and further designed and detailed by Philadelphia landscape architect Stuart Appel of wellsappel. Its 47,000 plants are subtropical and tropical, with the majority of them ferns.

No flowers bloom here on this tunnel of green profusion. Instead, sheer mass, naturally woven fluffy texture, variety of form and habit, and endless shades of green in prime condition create the attraction. Such is the Polypodium aureum Blue Star. Silvery-blue fronds on long petioles reach out from its position high on the wall. And only one plant is variegated: the Pteris fern.

For a plant to do well on the wall, they must never, ever have a lull. “We have to make sure that they’re looking good every single day of the year,” Baird says.

Asparagus fern has done well on the green wall, which completely covers both sides of a long hall with a vented glass top. The walls are composed of individually planted panels that easily pop out for close inspection, changing places with other panels of a different plant type, treatment or replacement.

Winter temperatures are a low of 50 degrees and a high of 70 degrees. At 70, the vents are opened. There is no air-conditioning so the vents are almost always open in summer. Shading begins with a light coat in March and heavier coats as temperatures warm. It’s removed in late October.

Asparagus fern thrive in the high light conditions of the wall and, with its tuberous roots tolerate drying out, so they do very well on the top of the wall. “The Victoria Bird’s Nest fern, Asplenium nidus ‘Victoria’, has done very well. It’s pretty too, so we like using that a lot.” Asplenium dimorphum ‘Austral Gem’ also flourishes.

But some plants are not too happy even when moved to another microhabitat with variances in lighting, temperature and nearness to the watering system.

Take Lemon Buttons Fern, Nephrolepis cordifolia 'Lemon Buttons'. “I think it’s going through a shedding period where it’s losing all its old growth and we just can’t have panels that are shedding all their leaves,” Baird says. “So we decided to take all those out and we’re replacing them with different ones.”

Maidenhair fern didn’t do well, beautiful in winter but yellowing in the heat of summer no matter what. Staff cut back the fronds but the plants never rebounded well. Most of the maidenhair has now been replaced with other species. “Again, we just can’t have empty panels that we cut back. We can’t wait for them to refresh. It’s a shame because it was so beautiful last year. Whenever the vents or a door opened, it had a lot of movement to it.”