It's obviously not the soil nutrients or ph on this planting. I think the key here was working the ground down about 8-10" and making it really fluffy. (If that makes sense?) we started out with little rain but then got it at the right times. I believe that the soft soil allowed them to grow this large.
Nevermind I see it now....we've never planted them as early as the first week in August but you're up north higher. Always heard if you get too warm of a season before colder weather moves in turnips can actually rot if planted too early...looks like the "fluffy" soil, rain at right times and cooler weather has created the perfect storm for you and those puppies will be awesome for you! Last year we had quite a few that size but that was in November not October....you may get another 1/2 inch or so depending on conditions.
At our cabin about an hour from home we generally get our first freeze around September 18, so we plant there the third to last weekend in July. Here at home our first freeze is around September 25, so I planted the first week in August. August 6th to be exact. I bet I didn't get germination for almost 2 weeks though, it was that dry at the time.
For you turnip growers, Did your deer discover the turnips on their own or did you have to dig up a few for them to discover them?
At our cabin they found them on their own. This is the first time I planted them at the new farm/home.
Last year at the swamp prop we introduced them to them....didn't do much till January and other food sources were sparse....then the ones that figured out what they were pounded them!!!! I did slice a few in half checking cams one time in December so they could smell them and so on.
I was thinking about adding them to our s Indiana property. I think it is worth a try at least once to see what happens