I had the same worry as well. I have many seedlings growing right now in my garage. At least this way I can keep the from the cold nights. I started everything last month since it should be 6-8 weeks from our last frost date but this weird weather has me concerned that the frost may last longer. I keep them under grow lights 16hrs a day for now. They are mainly veggies, so Im hoping the weather settles by end of march so I can set them out before the outgrow the space in my garage. After that heat wave I didnt want to spend the time to put up a temp green house to have everything die on me.

I have similar issues being in the mountains of So CA. It even snowed weekend before last, and there's a possibility of flurries tonight. My poor garden is a mess!