When the last few weeks of fall unfold, carrying the promise of an imminent frost, your garden will be well past its most fertile point. This period of winding down provides the perfect opportunity for cleaning and for a few simple tasks that can give you a head start when planting time comes in the spring. Perennials, such as chives, can be cut back for the next season: Cut the stems off right near the ground, giving the plants a neat appearance and readying them for spring regrowth. To save the plants you use for cooking, such as rosemary and thyme, pot them in a suitable container, place them in a sunny area in your kitchen, and use them throughout the winter.
For the rest of your garden, pull the dead annuals up, shake the soil from the roots, and rake the ground smooth. Compost the plants you've removed, and topdress the area. (Topdressing means applying a layer of fertilizer, mulch, or compost to enrich the soil; all of these provide nutrients and organic matter that leach into the soil throughout the winter.)