If you're starting seeds indoors, you can add the # of days to germination to the # of days to maturity -- then count back. At least that's the way I used to do it. Nowadays, I start nearly all of my seeds with wintersowing. (Even my tomatoes. I get later fruit than indoor sowing, but a ton more plants -- with a lot less stress.)

I did find this link. The info is for southern Wisconsin, so you can subtract 2 weeks from the starting date.

Here is a link that might be useful: Vegetable Planting and Harvest Dates

thank you so much! I printed it out and will use the info.
Susan