There was a thread about a month ago on this subject.

This should answer a lot of your questions.

Claire

Putting compost onto your garden in the fall allows the Soil Food Web to get that compost ready to feed your plants next spring when you plant them. By spring the SFW working in your soil will prepare that soil for planting for you.

I don't like to put compost down in the fall because the heavy winter rains will leach away some amount of nutrients. Particularly calcium and magnesium in my area. This may or may not be an issue wherever it is that you live.
How much would leach during a single winter I don't know, but around the globe there is a consistent and direct correlation between rainfall and soil fertility. More rain = poorer soils. So I cover my compost bins during the winter and hold off on compost application until spring.

Since the nutrients in compost are stable, not water soluble, they will not get "washed" out of soil over winter, provided the soil you have is properly and welll amended with organic matter that can hold soil nutrients. Where people do have a problem with nutrient leaching is in soils that lack sufficient levels of organic matter that could lock those nutrients in the soil, an acitve Soil Food Web.

Since the soil in much of the PNW is volcanic, it is quite rich in minerals. I like to mulch with compost (or leaves) in the fall to protect the soil from compaction, to prevent winter weeds, and, most of all, to free up space in the compost bins for incoming leaves :-).

Thank you all for the feedback. Sounds like my compost will work for me through the winter and come spring the area will be ready for some annuals! Admittedly, I'll probably add some more compost just before I plant!

What I usually do it dig in any remaining old compost, plant stuff, and then mulch with fresh compost to prevent weeds and conserve water.

Let's put it another way....the question was put, 'will it do any good to the soil given in fall'....then how about
can the compost come to something better allowed to percolate that much longer time over winter and then used in the spring when normal cultivation is carried out and the compost can be given where it counts more.

If the garden is designed in such a way that no one walks on the soil the plants grow in there is no reason to till, or cultivate, that soil once it has been well prepared, other than to maybe bury a few "weeds" growing there. although if that garden is planted well there should be no "weeds" because in thew words of Ann Lovejoy, "If you have "weeds" you do not have enough plants."
In the current issue of Organic Gardening magazine are two good articles about soil, one by Jeff Cox and oine Debra Prinzing about "Pat Marfisi's small but prolific vegetable garden."
Get your gardens soil ready for planting in the fall so you do not need to worry about doing that in the spring.