Yes, I’ve been following the latest research, and rooftop gardens can lower nearby air temperatures by a few degrees – usually around 2 to 4°C during the hottest part of the day, and sometimes even more in the evening. The plants release moisture through transpiration, which cools the air, and the green surface takes up less heat than concrete. It’s a small but noticeable change, especially when you add other green‑infrastructure elements to the mix.

Sure! The cooler effect grows with the square footage – a 200‑square‑meter garden can keep its spot a couple of degrees cooler than a smaller patch, and a 1,000‑square‑meter roof can drop the ambient temperature by a few more degrees. Plant density also matters: densely packed, leafy plants create more shade and transpire more moisture, so you get a stronger cooling signal. But even a thin layer of succulents or a few tall palms can give a measurable boost, especially if they’re spaced to maximize airflow and sun capture.

Exactly—south‑facing roofs get the most sun, so you’ll want fast‑growing, broad‑leaf species for maximum shading, but you don’t want to block the light out of the whole space below. Studies show that deep‑leafed trees or large shrubs, like eucalyptus or ficus, can drop temperatures by up to 5°C, while lighter plants such as grasses or sedum still provide a noticeable cooling effect—about 2 to 3°C—because they’re efficient at transpiration and don’t shade the area too much. Mixing species gives you both a steady cool breeze and a gentle, layered shade that keeps the rooftop comfy for people and plants alike.