The new sod/seed has to be down for at least 4-6 weeks or be mowed a minimum of 3 times before using Ortho Nutsedge Killer For Lawns Ready-To-Spray, so after 9 weeks you would be good to go!
Ortho Nutsedge Killer For Lawns Ready-To-Spray is not labeled for use in St Augustine grasses and it is not labeled for use in flower beds.