If you’re wandering around the back of the Barbican, you might spy a lot of steel tubes with a seemingly random selection of plants in them.
This is a “pop-up” (because everything is a pop-up these days) garden which is said to help trap particulates in the air. Its location right outside the car park might suggest the source of the particulates they want to prevent spreading. It was commissioned as part of the Barbican and Golden Lane low emission neighbourhood project and designed pro-bono by a landscape design firm, Studio xmpl.
The planting looks to my inexpert eye to look a bit scraggy at the moment, and I would have probably gone for plants with more foliage, but a local sign says that the plants chosen are noted for their ability to trap particulate drifting around in the atmosphere.
I guess they’ve gone for functionality over aesthetics.
The Barbican is actually a delightfully green area already with plants rioting over the concrete balconies and lots of ponds and waterfalls to improve the air quality.
At the moment, the pop-up garden is expected to last for a couple of years, until a permanent site is found.