gardenia

[fiveoffive]

What time of the year would be the best time to try and reduce the leaf size of my 5y old gardenia?

[Pup]

First things first how far along in its development stage is the tree? how old is the tree?.
Defoliation is practised for a number of reasons. One being to reduce there leaf size.

Most trees that are being developed need their leaves and needles to held put on growth.
So when you defoliate it slows the rate that it develops.
That is why it is recommended only on well fertilised and healthy stock, and only done once every 2 years.

There are always exceptions though in development, some trees can handle it more than others.

Cheers Pup

Edit I have seen that your Gardenia is just 5 years old. I would forget it for at least another 5, develop the tree. Just my