Maram valarpom, mazhai peruvom (Plant trees, get rain) is a common refrain across the state, echoed to promote greening initiatives. Tree planting drives are common activity in many quarters. From educational institutions to charitable organisations,z all engage in tree planting initiatives to mark important occasions. But how effective are these efforts? What happens to the saplings that are planted? Do they really contribute to greening the city?

Chennai’s shrinking green cover

Chennai has suffered considerable loss of green cover over the last two decades. A study by the Care Earth Trust in the aftermath of cyclone Vardah, that devastated large parts of the city and uprooted trees, pegged the city’s green cover at 15%. The recommended green cover for urban areas stands at 33%. Developmental activities such as the construction of Chennai Metro have often been carried out at the cost of trees in the city. 

Urbanisation has also dealt a big blow to open spaces in the city. Chennai falls way short of guidelines set by World Health Organisation (WHO) on open space per capita, which is 0.5 sq m in Chennai as against the recommended global WHO standard of 9 sq m. The lack of open spaces and green cover together with increasing concretization has led to the urban heat island effect in many crowded areas. Experts have also warned of average temperatures rising by as much as 2 degrees celsius in the coming decade. 

Is tree planting the panacea?

Chennaiites are painfully aware of the changes to its cityscape brought about by development and natural calamities. The increasing number of tree planting drives both by the government and citizens points to the urge to undo the damage by nurturing green cover. 

“Every year we have tree plantation drives as part of our school’s NSS program. We are given saplings and we plant them in and around our school and even take some home to plant in the neighborhood. We are encouraged to care for the ones that we plant, for as long as possible,” says Nrithya K, a student of Class VII of a prominent high school in the city.

Corporates and educational institutions, along with NGOs take up tree planting drives extensively. However, not many are aware of the basic guidelines to be followed that will ensure that the right kind of sapling is purchased and planted in the right environment. Very few organisations undertaking these drives are aware of greening and urban afforestation guidelines, or the harmful effect that invasive and alien species can cause if planted in the wrong areas.

“Our organisation holds plantation drives every two years or so. The CSR department organises these drives. However we have not received any instructions on care or maintenance after planting the saplings. We don’t know who takes care to water them, as the planting is most often outside our campus,” says Mohan S, an employee of an IT firm on OMR.

The right way

Greening guidelines for urban afforestation have been issued by the Ministry of Urban Development. The guidelines provide a broad framework for any large scale initiative to have a net positive effect on the environment. The guidelines are focused on efforts to be undertaken by the urban local bodies for afforestation and specify the kinds of species that are suitable for various locations and conditions: those that can serve as avenue trees along highways and broad roads, trees to be planted on inner roads, trees that are suited for water-logged or marshy areas.

The document also details the aftercare and maintenance required to be undertaken after planting of saplings. 

Care Earth Trust, in collaboration with the Chennai Corporation has conducted an extensive study across the city to identify suitable species of plants to be planted in each area and invasive, non-native species to be avoided.

Muthu Karthik N, Team Leader at Care Earth Trust shares the following ready reckoner formulated on the basis of the study: 

1. Check for street furniture, overhead wires, underground utilities like pipeline; (check with local civic staff for this)
2. Choice of species: consult experts before planting. Indigenous species should be planted and try to avoid single-species plantation (even if it’s a native plant).
3. At any cost, non-native species should be avoided. People prefer the exotics for their fast-growth and showy flowers, so that they can demonstrate the results.
4. Maintenance in ensuing years, especially in summer, must be proper and meticulous. This aspect should be discussed at the stage of planning the activity: Who will undertake the role of protecting, watering, manuring the plants, how these are to be done etc.
5. Protecting saplings from cattle / humans / vehicles is important; therefore, good tree guards should be in place.
6. Saplings should be supported using wooded stakings within the area emclosed by the tree guard.
7. Appropriate planting season is pre-monsoon; in summers, keep the saplings well watered and free of litter.
8. Try planting tall saplings for better results.
9. For smaller roads or streets with reduced canopy space, try to plant Palms.