i bought this plant about a month ago and in the last 2 weeks.. Not only are a lot of leaves turning yellow they are turning brown and drying out in large numbers and falling off

i live in Toronto, Canada and I have a west exposure balcony with sun late in the afternoon.

i've fertilized with all purpose Miracle Gro and water every third day or when the top 2 inches feels dry.. I would love to know what I'm doing wrong. I really like this thing