Yellow Leaves on Gardenia Bushes

Question

we have yellow leaves on our gardenias and I believe the pH of the soil is too low. I have been using Bloom Boost for feeding them. I have large gravel rocks at the bottom of the planter for drainage. What would I need to use to raise the pH? I used Miracle Grow potting soil to plant them in also.

Answer 1

These articles will help: https://www.gardeningknowhow.com/ornamental/flowers/gardenia/helping-a-gardenia-bush-with-yellow-leaves.htm
https://www.gardeningknowhow.com/ornamental/flowers/gardenia/fertilizing-gardenias-in-your-garden.htm