Jot it down.
Before doing a single one of the following things head out to the garden with pen and paper in hand (or camera!) and make some quick notes on what was where, how it worked, how it tasted, what to remember to do again, and what to remember to never do again. The ideal is a garden journal, but even a quick map is great to avoid planting members of the same family in the same space next year or to help remember where that new rhubarb plant went.
Ok, so it's time to tuck the garden away, but it is such a pleasure to plant bulbs for that dash of spring color so why not plant some garlic for a dash of flavor? It's not too late to tuck some in, and add the site of those little tasty green shoots to your winter daydreams. Some good, basic information on growing garlic is helpful whether this is the first time you've planted them or the hundreth as is a list of varieties available. Never done it before? Never fear! With garlic, there is nothing to lose. The scapes (flowerheads that need to be snipped) are tasty, and the bulbs...is there really a question?
A bittersweet but satisfying task for the fall is cleaning up the beds. Frost bitten basil, tomatoes, and other plants need to be moved out, cages brought in, and plant tags found. Unless your garden was struck with tomato blight or some other disease plan to pop everything in the compost bin. Add a those last grass clippings and leaves, and savor the thought of the fantastic growing material that will soon be created.
Feeling really motivated about composting? Check out this great little article on deep composting. Reminiscent of lasagna gardening deep composting makes use of the woody debris that can accumulate in fall while creating a new growing space that can be put to use almost immediately.
Build up soil.
Fall is a great time to give the garden soil a boost of healthy snacks for recharging the soil as well as continuing to build a solid soil foundation for future growing. Mix in shredded leaves (just run them over with the lawnmower), although it is important to consider what kind of leaves get thrown on the garden or into the compost bin. Walnut leaves are less than ideal, and maple leaves need to be well-shredded. Maple leaves tend to be nitrogen-fixing (holding onto the nitrogen while they break down rather than giving it out to the plants growing in the garden) although eventually they contribute.
A nice recipe for building up soil (literally and figuratively) can be found here (again reminiscent of lasagna gardening) is feasible for old and new beds alike.