I was thinking of trying to start some Lobelia cardinalis and L. siphilitica and Sagittaria latifolia from seed.

Is it too late to start these from seeds in flats?

If it take me a few months to get them growing and then translanted in late spring or early summer, will they have grown enough to winter over?

I have some wetlands behind my house that range from mostly shade to mostly sun. I would like to put in some attractive perennials and thought it might be fun and cheap to try it from seed.