Hi, 

These are not easy to grow in our climate. Here’s a response to a similar question from another master gardener, a couple years ago:

Ranunculus are considered a tender bulb in Minnesota. You should wait until the soil warms and nighttime temperatures stay around 60 degrees. When you are ready to plant soak the corms in warm water for 2-3 hours prior. Ranunculus should be planted in a sunny location, 2” deep in fertile soil. Compost can be added to increase nutrients. Keep them watered and once blooming fertilize weekly. All the best in growing these beautiful flowers

Here’s another site on growing these flowers here:

https://flowersinbloomedina.com/f/growing-ranunculus-in-minnesota

Good luck!