This reminds me of the concept of "winter sowing" popular among folks growing more ornamental things, but certainly applies to lots of useful permaculture plants. I haven't done it in years, but was planning to do a big batch this winter. Not sure if links are allowed (I'm fairly new!), but if you search "winter sowing", you'll come up with Trudi Davidoff's (sp?) website, which lists lots and lots of seed types that are successful this way. They tend to use labeled containers set out to overwinter in order to keep track of what germinates, but you could certainly do mixed sowings in dedicated areas.
I used to start a lot of my perennials, herbs, and some veggies this way - and yes, I found that those plants, especially the tomatoes, were much hardier throughout the growing season. I kind of love the container method, because I can sow new (recycled) containers in the winter "downtime" of January and February; it makes the wait for spring seem a little faster.