The civic authorities in Salt Lake are planning to turn the pillars of the east-west Metro or green line across the township green.

A senior official of the Bidhannagar Municipal Corporation said they would write to the Metro authorities asking whether vertical gardens could be set up on the pillars.

Metro pillars across New Town have vertical gardens that had been set up around six years back.

The gardens wrapped around these pillars are watered and maintained by the New Town Kolkata Development Authority (NKDA) which had obtained permission from the Metro Railway authorities.

According to an official of the Bidhannagar Municipal Corporation’s environment department, their department is going to send a letter of request to the Metro authorities asking them whether they can set up vertical gardens on the pillars that would not only look good but also help in keeping dust and air pollution levels in check.

Metro Railway pillars near the Karunamayee Metro Station in Salt Lake on Friday afternoon. Bishwarup Dutta

“We have decided to send in a letter asking the authorities to not only grant us permission but also corroborate with us to set up these gardens,” said the official.

Other than aesthetic reasons, there are other objectives behind the move.

Concrete is a great absorber of heat. It works as a heat sink and the areas around these concrete pillars are generally hotter compared to other places in the neighbourhood.

Apart from this, vertical gardens also help to keep dust and air pollution in check as well as help in increasing oxygen levels, the official added.

A senior Metro official on Friday said it was up to the authorities to decide what to do with the pillars.

“We decide what we want to do with the structures. Allowing advertisement hoardings on railway pillars is a practice across the country. We will consider if any request comes to us from the Salt Lake civic authorities,” a senior Metro official said.

According to the official, they are also for plantation practices and greening drives but they would also have to factor in their mode of revenue earnings.

Rahima Biwi Mondal, the mayoral council member in charge of environment at the Bidhannagar Municipal Corporation, said that they wanted to set up these gardens that would not only break the monotony of the concrete pillars but also help the environment.

“If we can build these gardens then they can help reduce air pollution levels as well as keep the places around the pillars much cooler,” said Mondal.

In New Town, small, fast-growing plants are laced around the pillars using a specially designed lightweight framework, a senior official of the New Town Kolkata Development Authority (NKDA) said.

A special mat capable of retaining water for several hours was initially set around the pillars before small pots with saplings were installed on them, the official said.

Truck-mounted pumps and drip-irrigation method are used to water these plants.

Bryophyllum pinnatum or air plant, various ferns and flowering plants that can survive on little water and minimum maintenance have been planted.

Heat-resilient plants such as euphorbia, phalphysia, yucca, sasivera, nerium, thuja and chuphia have been planted in these gardens.

More than 300 plants are accommodated on each of the pillars, each of which is around 30 feet high.

“A single such garden on a Metro pillar can release more than 500 litre of oxygen every day,” a senior NKDA official said.