Dan 2007: You should try to get them in the ground as early as possible. Last year, I found an online source that said, for each day's delay planting after April 1st, there was roughly a 2% decline in yield. This is due to the strong photoperiodism in favas. Later planting results in smaller and smaller plants. I think I posted a link to this on the bean/pea forum in a fava thread. You might try searching for it if intested. Or, if you want, I can try to find the data again later, don't have time right now to do it, unfortunately. I planted mine last year on March 30th, and they did just fine, germinating well and weathering several boughts of very cold weather and snow after sowing and germination. I'm in the N.W. suburbs of Detroit, so we have the same weather.

Snap beans from the grocery will almost never be mature enough to have viable seed. And even in the best case scenario (which would be worst case for the grocer, having over-ripe beans) you won't get enough plants to make it worthwhile. What you will mostly get is failure. You are far better off just purchasing bean seed which will germinate reliably, rather than purchasing produce. The good news is that if the immature bean seed does grow, you will get plants that are true-to-type with with what you originally purchased. While hybrids are quite common in many garden vegetables, there are no hybrid beans... and likely never will be. It is too impractical to produce hybrid bean seed, both because of the flower structure, and because for each flower pollinated, you get 10 seeds at best. Contrast that with a tomato or pepper, where a single hand-pollinated flower can yield hundreds of seeds. While some beans may start out as crosses during the breeding process, the cross will be stabilized into an open pollinated variety before it is released commercially.

Wow, now I am worried about planting the favas I ordered from an Italian importer. Favas aren't on the seed racks around here. From the sounds of your posts it might get too hot here in the summer and too much snow in the winter. Oh well, all I can do is try. I shared a few with a friend who planted them in peat pots and they sprouted right away indoors. Lately, I've seen many cooks on the food channel using fresh favas in recipes. My family is of Portuguese descent, and my late mother fixed dry ones with onions and curry which were wonderful. It's a childhood memory of mine having grown up in Hawaii. I have heard about them causing severe allergic reactions in certain people, but I don't know much about that. I see where freedom farmer mentioned that. But he also says they grow fairly well in MA. I shall give it a try since there is more snow there than in Kansas.

They work better as a fall crop than as a spring one in our climate. Our spring cool season is usually too short for them as the heat generally arrives too early for them to make a crop here. Now, last year's prolonged cool and rainy spring might have been the rare spring when fava beans might have had a chance to produce in spring from a late winter/early spring planting. You're quite a distance further north than I am, but I don't think your heat arrives that much later than mine. However, if you are able to successfully get a good yield in spring from winter-planted cauliflower and brussels sprouts, then you might stay cool enough long enough there in springtime to get a good yield from spring fava beans. Down here in southcentral OK, it is rare to harvest much of anything from cauliflower and brussels sprouts in spring due to the early onset of the heat, so for us down here, they are more of a fall crop, and the same is true of favas.