If you are interested in extending the harvest season of your garden, I highly recommend reading the book 'Four Season Harvest' by Eliot Coleman. It's really well written and very engaging. He and his wife traveled to France and the books talks a lot about how the French extend their growing seasons. He applies their knowledge to his American garden and voila!! He has food, fresh from his garden 365 days a year.
Here is what I am doing to extend our harvest...
~Installing a mini hoop to cover my 6 tomato plants. A simple cover in Oregon can extend the harvest until December if all goes well. Our tomatoes need protection from rain and wind more than frost for the most part.
~Creating a raised bed with horse poo as the bottom layer of soil (warmth as it decomposes) to grow Broccolini, Kale, Carrots and Swiss Chard in.
~Planting pots with Mesculen salad blend, Swiss Chard, Arugula etc. Where some people might put a pot of Pansies by their front door, I'm going to have a pot of Bright Lights Swiss Chard. I'm all for edible landscaping.
~Locating a permanent spot for garlic and planting a ton. We will not have fresh garlic until next spring but the wait will be worth it!
~Starting Artichoke seeds, planting them out in the garden, waiting a year to see if we get Artichokes.
I plan on starting the Arugula and Mesculen pots at staggered times so my harvests will continue.