With the maximum temperature in the city reaching 37 degree Celsius, citizens have been running for shade from the searing heat, finding shelter in lung spaces such as Cubbon Park and Lalbagh Botanical Garden. But the heat has been taking its toll on plants too.

Horticulture Department officials said maintaining the plants is using up the entire capacity of water available for the parks owing to the rise in temperature. Lalbagh is spread over 240 acres and Cubbon Park across 177 acres.

M. Jagadeesh, Joint Director, Parks and Gardens, Horticulture Department said in both Cubbon Park and Lalbagh, 70% of the plants are perennial. “The heat will not have much of an impact on the trees. But maintaining herbaceous plants and new saplings is a challenge. To protect herbaceous plants from the heat, we have to ensure shade,” he said.

The authorities have increased the frequency of irrigation. “We normally have to irrigate three times a week, but now we are doing it four times a week. The total requirement of water for the gardens is quite high: Lalbagh requires 1.5 million litres per day (MLD), which is the full capacity of the sewage treatment plant (STP) we have. On normal days, the requirement would be around 1.2 MLD. In Cubbon Park, we usually use 1.5 MLD. But for summer, we are using the full 4 MLD meant for the park, Raj Bhavan, Indira Gandhi Musical Fountain Park and Vidhana Soudha,” said Mr. Jagadeesh.

Mahantesh Murgod, Deputy Director, Cubbon Park, said apart from treated water, they had rejuvenated seven wells inside the park around a year-and-a-half ago and interconnected them, which is coming to their aid. “During summer, the frequency of water spraying has to be increased. We are also going to start work on rainwater harvesting systems in 15 days, and hope it will help in raising the groundwater table for the future,” he said.

Lawns need frequent watering, as they are exposed to the sun, officials said. Sprinklers are used on alternate days now instead of once a week or in 10 day when it rains, they said.

Horticulture authorities are also trying out new techniques to cope with the heat. One of them is mulching, through which organic waste is used at the plant base, which facilitates moisture retention for up to three days.