Yes, they will compost in place...it's called sheet composting.

The advantages of sheet composting include ease of implementation (maybe not if you are going to the trouble of cutting into 1 - 3" pieces) and the moisture retention qualities of mulch.

The disadvantages of sheet composting include slow rate of decomposition and it is not compatible with composting all materials. Additionally, if the raw materials contain weed seed or plant pathogens, these will not be destroyed in the sheet composting process.

And it depends on the look you want for your garden, sheet composting may look very casual (messy). I add occasional stems, spent flowers, a few weeds onto beds in hot weather when I know they will wilt and dry up quickly, but for the most part larger pieces here where it stays so damp for so long provide hiding places for small slugs.

More than one school of thought:

One is that they will, as you suggest, return nutrients to the soil, and thus are a positive in the garden.

A second is that spent vegetation carries risk as being haven to pathogens & legged wigglies such that the benefit of allowing it to remain is outweighed by the risk, making it the opinion of the latter group that it is a negative.

Al

I see that 6 seconds (between posting times) is enough to turn me into a copy-cat. ;o)

Al

Well Al, legged wigglies is certainly more poetic than my term 'slugs'...:) My slugs have no legs.

Other than that, what is it they say about great minds ?

My slugs don't have legs either - but they all have feet. How paradoxical is that?

"Great minds are a terrible thing to waste"? Is THIS the one you're wondering after? Thought not. ;o)

Can anyone tell I'm bored with the general lack of activity around here? Anyone? Hellloooo?

Al

tapla, I take it you have not been hit by a Winter Sowing frenzy. Check out the link below. Folks there have been having a grand time sowing since December and the frenzy is getting more intense. The WSers have had no dull moment.

Here is a link that might be useful: Winter Sowing Outdoors! - FAQ

Three main reasons why I won't leave plant debris in the beds to decompose: aphid eggs, whitefly eggs, spider mite eggs!

When doing the fall clean-up, I'm sorta in-between morz-8 and the others. For the past couple decades, I've often put my trimmings on the nearby ground (which is already mulched) although I cut long stems down to about 6" pieces, but then I top the trimmings with a good layer of mulch (usually a dozen newspaper pages topped with 2" shredded leaves). I haven't had any of rhizo's problems, but that may be because I don't have whiteflies or spider mites, or it may be because the layering smothers the potential problems. Whichever, it's faster than hauling awkward trimmings to the compost.

To be truthful, I don't have those problems either, but remain a little paranoid about getting a nice population started here. But that's ME ;-)