Plant ID

Lsinshirley

Hello, think the photo is upside down. When should I trim This back? New home / new plants, ☺️

Lsinshirley

rachelQrtJHBjb

Hello. You have a lovely but large spiraea. Here's the link to the RHS advice page, which encourages pruning in spring as it flowers on new wood.
https://www.rhs.org.uk/advice/profile?pid=166