After you have harvested all of your veggies for the year, instead of composting your end of the season organic matter, add it to your garden. With the soil still being warm, the material will decompose quickly, saving you the time of amending your soil in spring.
You can add any vegetable or plant material, along with grass clippings and leaves. You’ll want to chop up the larger pieces, such as tree leaves or garden residue. Lawn mowers with bagging attachments work well to shred this material and collect it in one operation.
Spread the organic matter to about 3” deep and work in the soil. The warmer days will quickly turn your garden refuse into black gold. Organic matter may be added every two weeks or so from September until the first weeks of December.
Organic matter loosens the soil, allowing the roots to spread out and grow. It helps the soil hold water and important plant nutrients. Adding organic matter increases the population of beneficial microbes, boosts pH and can suppress certain diseases. Ideally you want to add enough so that your soil gets to the consistency of chocolate cake, so loose you could plant with your hands (not that you would want to). The amount really depends upon your soil. If it turns as hard as bricks in summer, load it up. You can’t use too much. 6” of humus (decomposed organic matter) for needy soil will help considerably. In an existing bed, place 2-3” around your plants, the worms will work it into the soil. Continue to add organic matter every year, the more the better.