We had a frost last week, after I stupidly planted out a few of the tender plants I bought last weekend. Lesson learned there. (I covered them – they did survive. Fortunately, it was only four plants.) So the rest of the plants I bought are jammed in with my seedlings under the grow lights, until at least Memorial Day.
The exception to that are a few flats that came in cardboard containers. I’m not comfortable leaving those in them, since they dry out so much more quickly. So those have been planted in their intended containers, and will hang out with the dahlias until it’s reliably warmed up.