All my life we always ate turnips cubed and boiled, my aunt always added sugar to sweeten them. Never tried them mashed. They kinda stink and that's not my favorite way. Sliced and fried in bacon grease is much better.
On the way to a hunting stand I'll pull up a couple, peel off the tough outer lay, and snack. They're pretty good raw. I believe it helps mask the scent of my breath.
Here in Southern Illinois we won't even plant turnips for another month or more. I guess its different up north.