As a bonus, you will improve your soil and reduce the chance that diseases will take hold in your garden.
It's also worth noting that in a large vegetable garden, you don't have to wait until everything is done growing to begin your end-of-the-season cleanup. As you finish harvesting a crop, go ahead and clean up that section of the garden.
First, remove any plants that show signs of disease, as well as the mulch around them, and burn them. Don't toss them on your compost pile, or you'll reintroduce the disease to your garden later.
Particularly if you've had any signs of disease on your tomato plants, you probably should sterilize the soil. Tomato diseases can be stubborn and destructive, and they overwinter in the soil and on garden tools.
You can sterilize the soil by covering it in plastic to heat it. Old but clean shower curtains and plastic tarps work well, or you can buy a roll of heavy plastic. Cover the infected area and weight the corners and edges of the plastic with bricks or rocks, then cover the edges with dirt. The point is to seal the edges to keep in as much heat as possible.
It's best to begin this process while the temperatures are still warm. Leave the plastic in place for at least two months. At that point, you can till the soil.
On parts of the garden that appear to be disease-free, you can either remove the plants and mulch to your compost pile, or compost the plants and mulch directly into the soil. Some gardeners prefer the latter approach as a no-fuss way to amend the soil with organic matter.
To compost the healthy plants and mulch in the garden, uproot the plants and lay them on the ground. Corn stalks and tomato plants can be very difficult to uproot until the plant is entirely dead. You may need to use large shears to cut the plants off just above ground and then to break up the plants themselves.
Run over the mulch and plant material with a lawn mower to break it up. The kitchen equivalent for what you are doing here is mincing. When you have everything ground up, till it under.
This also is an opportunity to incorporate finished compost, grass clippings and leaves into the garden. Spread them on the surface of the soil before you fire up the tiller.
Some gardeners leave compostable material, including kitchen scraps, intact on the top of the soil. A couple of red flags should go up here. First of all, the kitchen scraps will invite all manner of creature into your garden. Trust me, you don't want animals to become accustomed to eating in your garden. Second, organic matter that rots on the surface of the soil really isn't doing the soil any good.
Your end-of-the-season tilling should draw the organic material down into the top 6 inches of the soil, where decomposition happens fairly quickly. For best results, do a crisscross tilling. For example, till the garden or a section of it with north-south passes, then go back and retill the area with east-west passes. In this way, you will make sure that no earth remains unturned. Many tillers invariably leave a ridge of untilled dirt, even when you overlap your rows.
If you go through this process, your soil will be easier to work and your yields will be better next spring. In the best-case scenario, you'll also find a warm day in February or early March to till the garden again, to aerate the soil before the new gardening season begins.
-- When she's not writing about foods and gardening, Gwyn Mellinger is teaching journalism at Baker University. Her phone number is (785) 594-4554.