Q.Growing under a large radiata pine
I live in the southern highlands of NSW and in the front garden have a very large radiata pine, which is too expensive to remove. I have tried to grow azaleas but most have died and I am desperate to find something that grows well and fills up the space. I have tried clivia but that is also reluctant to grow. I have improved the soil with compost and new soil. It is also a shady spot.

Here is an article that will provide you with many options for planting under pine trees:
https://chriscondello.wordpress.com/2013/05/14/practical-permaculture-planting-under-pine-trees/