Usually the seed packet will tell you. Poppies, sweet peas, bachelor
buttons, larkspur, alyssum, linaria, candytuft and many other cold-hardy
annuals can be sown now - in fact, could have been sown in March. On the
other hand, marigolds, zinnias, nasturtiums, four- oclocks, and most other
hot-weather late summer blooming annuals should be sown around the time of
the last expected frost. (They will usually not germinate until the danger
of frost has passed). Some seeds of warm weather annuals will rot in cold
soil, so it is important that your soil is starting to warm up too.
wrote in message
oups.com...
In general, can annuals be sown before the last frost?

The soil is warm, weather trend has been great. But, we'll probably see
a frost (zone 5).

Any input appreciated.
-Felder