Yes. I know Madurai is very famous for Malli. There are many farm lands and houses are available to get jasmine(malli). Madurai malli always Mannakkum malli.
When I hear the name Madurai, it is usually come along with the name Jasmine(Malli in Tamil).The climatic conditions for the growth of Jasmine plant is very apt.The soil condition and the water content necessary for the growth of it is very suitable.
Every town has its unique soil,for example Black soil in Coimbatore which is an exact soil for the growth of Cotton Plants.Jasmine plants grow in many other places too but Madurai produces the unique of its kind.
I am in Madurai but I haven't seen not even a single jasmine farm in Madurai. I think they must be in villages that is around Madurai. Madurai contain lots of villages in its surrounding. Protta in Madurai tastes different and will be nice. Madurai is also popularly called as Toonga Nagaram.