Q.How can I stop leaves from turning brown?
I bought 3 months ago from Lowe’s it was doing good. Leaves started browning recently.
I placed pebbles in bottom of pot holder to 1/2 ” to 3/4 to raise pot preventing sitting in water and provide humidity. Good light SW window. .?? How can I restore green???
I believe that water management is the key issue, not too much or too little. From what you say about the pot holder and not sitting in water, that is one important step. But could you possibly over watering and causing hypoxia (lack of oxygen) for roots and root rot?
I recommend a soil moisture meter to take the guess work out of when to water. https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm
If you feel that you are watering appropriately, then my second guess on leaves yellowing/browining would be a nutrient deficiency. Fertilize with a complete organic fertilizer like this example: