Keep an eye on the Fall Crop thread
, because I'll be touching on Winter Crops over there, and some people have mentioned it already. The thing is, especially in the north, a lot of plants needed to be planted a lot earlier than you might think because they have to have the chance to grow near to maturity in order to survive the winter.
Garlic is an exception -- in the north
, should be planted when you plant spring flowering bulbs ... mid-Oct ~ Early-Nov in my area.
RIGHT NOW, if you sow parsley, they'll get established and may be able to overwinter. In spring, you can harvest until they start to flower.
Lacinato/Dinosaur Kale have successfully overwintered in my garden with minimum protection
Raddichio has also overwintered in my garden, as have carrots. Brussels sprouts survived but didn't make sprouts in spring as intended, but they may have been too immature going into winter.
If you are interested in grain, Winter Rye and Winter Wheat will overwinter and grow next spring but it won't be ready to harvest until later in spring.
You can grow winter covercrops -- not to harvest and eat but to enrich your garden soil. All need to be sown late summer/early fall to grow sufficiently before being winterkilled or to be turned under in spring.
WITH PROTECTION as outlined in the book Cynthia mentioned, you could grow more.