We had camellias at the back fence for a hedge,but they all died. Why?

could be a number of reasons, if planted at edge of the yard and there is a slope the water run off the slope could lead to lack of water getting to the roots, perhaps they contracted some type of blight, or they just might have lacked enough nutrients you get from miracle grow because they are a plant that needs acid for plants

Plants need good soil, light, water and heat to grow. One of these is missing in the correct proportion for that specific plant. Get a soil test before you start adding nutrients to your soil that it may not need.

It might have to do with the fence. The plants might not be getting enough sunlight also

They do Lose their leaves at a certain point. Leave them alone they will come back.

Thankyou Luci

Thankyou Sal