Q.The Leaves Are Falling Off – Post Fertilization
Bushes are planted in an area with small white rocks and recently fertilized with 10-10-10 fertilizer; leaves are now falling off.
Certified GKH Gardening Expert
Unfortunately, you don't mention the type of shrubs that has been affected. It is hard to say what happened, but it could be nutrient burn, based on the information that you have provided.
Here are a couple of articles that will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/fertilizer-burn-in-gardens.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/what-is-fertilizer-burn.htm