Wait for the cold to pass turnips can be sensitive to frost early on. If you're sprouting them indoors, you can plant in a week or two, once the risk of frost drops. Just make sure the soil is well drained and they get plenty of sunI'm trying to grow some purpletop turnips and I believe that now is near the time to plant. I live in SE Ohio in the middle of zones 6a and 6b. The 10 day forecast gives me a low of 27F, although I'm not sure how much I believe that number. Last fall I tried to sow them directly, but they never sprouted. This time I plan to sprout them before planting, and this time with better soil. I'm still not sure exactly when to plant them though. I was thinking this week or next week. I'm new to all of this so I'd appreciate any tips.