Spirea Leaves Are Turning Brown And Dropping

Question From: Chantilly, Virginia, United States
Q: I planted newly purchased spires in a pot till fall. Used fox farm ocean Forrest potting soil because it has good amendments. But leaves are turning brown and dropping. Have checked soil for moisture. What did I do wrong?

A: Too much fertilizer will do it. If they were in a green house and then exposed to full sun conditions and high heat they may have literally sunburned. Best And Happy Yardening, Nancy