My Bottle Bush Tree’s Leaves Are Yellow.what Do I Use?
in the HOT Arizona desert
Certified GKH Gardening Expert
Unfortunately, your photo did not come through, and it depends on what is causing the yellow leaves and where it occurs.
Make sure that your soil pH is between 5.5 to 7, first. If this is way high, or way low, then correcting will be necessary.
If the pH falls within range of normal, then you may need to supplement with nitrogen, iron, or calcium and magnesium, depending on where the yellowing occurs, exactly.
If your soil nutrient levels read fine, then you may have salt build up. This can be chelated out with citric acid.
Here are some articles that will help: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm