Always reluctant to speak in absolutes, but based on my experience, I'd disagree. First, most compost, even commercially prepared compost, is not fully decomposed. Fully decomposed compost is humus and tends to be very expensive when purchased and of an extremely uniform color and texture.

Compost under most normal conditions (not 100% "finished") tends to be very attractive to earthworms. And you are also overlooking the natural accumulation of organic matter over and above any application of compost - plant parts and roots, small weeds that do not mature or are disturbed, windblown leaves and other plant debris - that all build up on the soil surface or very close to it.

As one who adds OM to their garden pretty much solely through the use of an annual (or twice annual if I can manage it) compost mulch, I can report a very high population of worms - it's impossible to cultivate even the smallest area without disturbing several and castings are evident throughout. I would also add that my garden is primarily ornamentals and cultivation is limited to the addition of new plantings, division or transplanting of existing plants and light weeding.

Add to that- worms aren't the only ones doing the tilling and soil incorporation (excepting hard clays). I'd be more concerned about weeds when using only compost as a mulch.

I forgot to mention it's only about a 1" deep layer at most of compost that's added per year. Is this enough? It doesn't seem so because I see very little worms.

Also forgot to mention these garden beds are never allowed to have a buildup of organic material - they're always kept clean of that and bare

Which is it? Does it have an inch of compost added each year or is it kept clean and bare? The two seem mutually exclusinve.

If you mean that your friend clears the old away before adding new, that may be part of the reason the worms are staying little. If he'd leave the compost there and add to it each year, maybe they'd get bigger. And maybe the compost would have more of a chance to get incorporated into the soil.

Sorry I wasn't clear enough.

What happens is 1" of compost per year and everything else inetween applications (but NOT compost) are cleared off

Worms are a good indicator of a healthy soil. However lack of worms are not necessarily a indicator of poor soil.

If your friend is satifisfied with her plants and her landscape; then that person's plan of using compost as mulch is successful for that person. Each gardener will do what they are comfortable with and what works for them. Every soil is different, as are personal preferences for appearance and available effort.

Some people prefer the look of black compost (or soil) as a back drop for their vegetation, as opposed to other mulches. Typically these people are either meticulous weeders or they use a pre-emergent along with their compost mulch.

I use alot of leaf mulch or wood chip mulch because I prefer not to do a lot of weeding.

What I'm concerned about is the health of the soil, which seems to be lacking, considering there are basically no worms. I know that if the plants are doing ok now, they can do better with a healthy soil

Someone I know only mulches their plants with wood chips and never uses compost. Their plants are doomed...

How do you know there are "basically no worms"? Have you gone over and checked it out personally? Populations of worms can vary dramatically, even from one area of the garden to another and since the range of most common earthworms includes the top several feet of the soil, it is quite possible not to see many just under the surface yet still have a healthy soil and a decent worm population.

It is estimated that arable land contains 53,000 worms per acre. Recent studies have revised that number to as many as 250,000/acre for relatively "poor" soil conditions to as high as 1.75 million/acre for very fertile farmland. And environmental as well as soil conditions play a role in worm populations as well, drought and heat primarily. Drought and heat will drive worms down deep into the substrate where they are not visible to us unless serious digging is involved. The use of herbicides doesn't seem to have much impact on worm populations, however the use of other pesticides can, as does repeated use of chemical fertilizers.

yes, i have checked the various beds out. i don't see much evidence of worms, at all, even when digging to put plants in.

Really? You check out your neighbor's planting areas, looking for worms? I'm not sure I would appreciate my neighbors putzing around in my gardens or soil - in fact, I know I wouldn't appreciate it - but perhaps you do some gardening work for her. In that case, maybe you could encourage her to increase her use of OM to increase the worm populations and thereby improve her soils. 1" of compost is not all that much and not even very effective as a mulch, let alone adding significant amounts of OM.

I work for this person and we have multiple gardens we do. I've worked in all of them - examined all of them - dug in all of them - monitered all of them over a season.

to me it seems like compost out of a bag wouldn't do nearly as much as uncomposted matieral. sure, compost outta a bag is never necessarily fully done, but it's pretty close to fully done.

This is what I've concluded, feel free to express why you think I'm wrong if you do

Adding compost is good because it adds organic material
But it doesn't support soil life nearly as much as uncomposted mulch does. Yes?

Compost out of a bag (commercially prepared) is not very different than homemade compost, perhaps a little more closely managed and controlled is all. And I'm surprised no one else has chimed in yet to report of the benefits of their applications of compost - from whatever source - to their gardens and the state of the microbial life. Compost by definition is not complete - when it is completely decomposed and no further degradation is possible, it then becomes humus, a very stable element that is a major component of a balanced soil.

What you see with your naked eye as "finished" compost and a product that appears to be fully decomposed is rather different from humus. The difference will show up under a microscope. And until it hits that stable form, it will continue to suppy a food source to whatever is living in the soil and thereby to the plants themselves. And the advantages of either compost (in whatever stage of completion) or humus go far beyond just merely supplying food to soil creatures.

So would you say that as long as you add enough, compost is just as valuable in supporting biological soil life as an undecomposted mulch (seaweed, leaves, etc)?

Does her soil tend toward the sandy and acidic? Our sandy, acidic soil had no worms in it - never saw one once - until we'd been adding organic matter for 3-4 years.

Your terms are a little confusing hooray. I think of compost as a soil food, and mulch as a weed suppressant and erosion preventative that will gradually turn into soil food. By mulch I mean sawdust, wood shavings, eelgrass. In the fall we cover all the beds with something for over winter, something we won't be removing in spring: either compost or half-rotted leaves, or we grow a green manure like rye grass. This year we had rotting straw so we covered the layer of compost with a layer of straw - luxury for the soil organisms. 'Never leave soil bare' is a fundamental principle of organic gardening.

HFO, to answer your last question, I would say it depends entirely on the type of undecomposed mulch. Some are much slower to breakdown and therefore inhibit the development of some beneficial organisms. Others can encourage the development of pathogenic organisms, at least temporarily. And understand that "mulch" is a rather loose term that can apply to anything used as topdressing to soil, including a whole range of inorganic products that do absolutely nothing to develop the soil or its biological life but offer other advantages.

I really think you need to stop looking for absolutes - there are none - and concentrate on what works best for you. And this is a process that relates entirely to time, experience and your specific conditions, which will be different from anyone else's.

my question doesn't have to do with different environments, as far as i can tell, and im not asking for absolutes

i'm asking which supports bio life more:
compost from a bag, or uncomposted organic mulch

im guessing it's the latter

You are indeed asking for absolutes. As I and others have tried to point throughout all your many recents threads, it is never a simple yes or no, one is better, one is not answer. It depends.

this soil isn't compacted or claylike. it's black and reltivly soft but with no worms

its black and reltivly soft but no worms.
you will have to buy some or do like i did'dig some and turn them loose in your garden bed.

I have 6 inches of sand on top of red clay. I added compost and had lovely plants several years before the worms arrived. Worms aren't the end all and be all of a good garden plot. I don't till because I'm scared of mixing the sand and clay together, but I do have a pretty good garden going.