Thanks for the question.

Once night temperatures remain above freezing, you can uncover things. Looking at historical weather data, the average date for the last frost in Aitkin County is during the first week in May. Aitkin County is somewhere between growing zones 3 and 4. These are colder growing zones than seen, for example, in the Metro Area of Minneapolis/St. Paul. For this reason the uncovering of your gardens should be later than the Metro Area. However since this year (2021), spring weather seems to be one or two weeks ahead of historical averages, we would suggest that you keep your gardens covered for another week or so and then uncover them. It is far better to uncover things slightly too late than too early.

Good Luck!!