Focus on increasing employee retention instead because trying to reduce turnover just focuses on keeping people on the payroll. Increasing retention focuses on keeping the right people on the payroll longer.
One way to accomplish this is to give them a view of what the future could be. Create an org chart showing all of the opportunities you envision for your workforce over the next few years. Show them those that now exist and those you expect to develop to inspire them to buy into your goals.
P.S. If you’re using The 5 Firsts: A Simple System to On-board and Retain Top Talent, this would be a great tool to add to the end-of-the-first-month-on-the-job discussion.