Noob question: can I down convert an existing 60PSI line to 25PSI?

Reason for my question is that my backyard is finally getting converted into a series of large garden beds. where I live during summer typically we are only able to water lawns once a week, and this year due to low snowpack we will likely not be able to water the lawns.

I have two 60-65 Psi lawn sprinkler lines running in the backyard and wondered if I could both split them while reducing the pressure, to provide weeper line coverage for the garden beds.

I know there are pressure 'downregulators' but is it just a matter of putting them on the line and then it's fine, or do I need anything else to make sure if doesn't do something like blow up or leak everywhere?