Q.MY SMALL GARDENIA TREE
I CHECKED POT FOR GOOD DRAINAGE. I CHANGED THE SOIL TO THE BASIC MIRICLE GROW. I CHECKED THE ROOTS. THEY ARE A NORMAL COLOR, AND DO NOT SEEM TO HAVE THE WORM PROBLEM. THE PLANT IS NOT DEAD. THE PLANT IS GROWING, BUT NEW LEAFS THAT COME OUT ARE BROWN. SOME LEAVES ARE YELLOW WITH BROWN ON EDGE. HAS BEEN INDOORS, AND MOVED TO OUTSIDE FOR SUN DURING SUMMER. WHAT IS WRONG?

Certified GKH Gardening Expert
You may want to check the soil to make sure it has the right nutrients, etc. They need acidic soil and partial sun.
Here's an article that should help: https://www.gardeningknowhow.com/edible/helping-a-gardenia-bush-with-yellow-leaves.htm