how to save my dying Dahlia plant

2 months ago

I bought this beautiful dahlia plant recently with lot of flowers and bloom. I had it in enough big pot and place it in my balcony. but there we don't have direct sunlight. though we live in Pune India where there is enough hot weather. still my plant is dying within a month.
leaves stared getting dry and some fungal on blooms. please help me how to save my dying Dahlia.
I have another balcony where 4-5 hours sunlight comes. so now i have kept my pot there. Do you have another suggestion?