Q.Why Is My Choisya So Unhappy?
Hi, I’ve had a Mexican orange blossom for about three years and it never really took; scant flowering and always lack luster. It is not the Sundance variety (unless mislabeled from nursery). I’ve tried fertilizing (not overly so, I think) using Iron-tone and Holly-tone. I’ve checked solid pH and rerouted a downspout nearby in case she was drowning… any other thoughts or what am I doing wrong? The top growth is pale yellow, periodically with light brown hues. See attached images… please and thank you. Hope all is well.. Tim

Certified GKH Gardening Expert
It does appear to have sustained damage from overwatering at some point. This looks to have led to an infection!
I would recommend using fungicides until you notice that it starts to appear healthy. Once it shows signs of clearing up, you can stop the fungicide use.
Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/ornamental/shrubs/choisya/choisya-shrub-care.htm